Trial Outcomes & Findings for Spinal Control During Functional Activities to Improve Low Back Pain Outcomes (NCT NCT02027623)

NCT ID: NCT02027623

Last Updated: 2020-08-21

Results Overview

Background/Purpose: The 10-item Modified Oswestry Disability Questionnaire is a disease-specific measure that provides an index of a participant's perceived low back pain-related functional limitation. Procedure: Participants will answer each of the 10 questions by placing a mark in the one box that best describes his current condition. Since a participant may feel that 2 of the statements describe his condition, he is instructed to mark only the box that most closely describes his current condition. Scoring: Each item is given a value from 0-5. The total score is the sum of all questions divided by 50, multiplied by 100 to get a percent. 100 represents the highest level of limitation.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 154 participants
• Primary outcome timeframe: Baseline, completion of initial 6 week intervention phase
• Results posted on: 2020-08-21

Participant Flow

Recruitment was by way of flyers placed in the community and physician offices, ads and interviews through local media and clinics in the region. Recruitment spanned December 2013 to August 2016.

Participant milestones

Measure	Motor Skill Training The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Overall Study STARTED	77	77
Overall Study COMPLETED	68	65
Overall Study NOT COMPLETED	9	12

Reasons for withdrawal

Measure	Motor Skill Training The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Overall Study Lost to Follow-up	3	3
Overall Study Withdrawal by Subject	6	9

Baseline Characteristics

Spinal Control During Functional Activities to Improve Low Back Pain Outcomes

Baseline characteristics by cohort

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.	Total n=149 Participants Total of all reporting groups
Age, Continuous	42.4 years STANDARD_DEVIATION 11.8 • n=93 Participants	42.6 years STANDARD_DEVIATION 11.7 • n=4 Participants	42.5 years STANDARD_DEVIATION 11.7 • n=27 Participants
Sex: Female, Male Female	50 Participants n=93 Participants	41 Participants n=4 Participants	91 Participants n=27 Participants
Sex: Female, Male Male	24 Participants n=93 Participants	34 Participants n=4 Participants	58 Participants n=27 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=93 Participants	0 Participants n=4 Participants	1 Participants n=27 Participants
Race (NIH/OMB) Asian	2 Participants n=93 Participants	5 Participants n=4 Participants	7 Participants n=27 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=93 Participants	1 Participants n=4 Participants	1 Participants n=27 Participants
Race (NIH/OMB) Black or African American	12 Participants n=93 Participants	11 Participants n=4 Participants	23 Participants n=27 Participants
Race (NIH/OMB) White	54 Participants n=93 Participants	56 Participants n=4 Participants	110 Participants n=27 Participants
Race (NIH/OMB) More than one race	5 Participants n=93 Participants	1 Participants n=4 Participants	6 Participants n=27 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants	1 Participants n=4 Participants	1 Participants n=27 Participants
Body Mass Index (BMI)	25.3 kg/m^2 STANDARD_DEVIATION 3.2 • n=93 Participants	26.1 kg/m^2 STANDARD_DEVIATION 3.1 • n=4 Participants	25.7 kg/m^2 STANDARD_DEVIATION 3.2 • n=27 Participants
Married or living with significant other	45 Participants n=93 Participants	55 Participants n=4 Participants	100 Participants n=27 Participants
Completed at least some college	67 Participants n=93 Participants	72 Participants n=4 Participants	139 Participants n=27 Participants
Employment situation Working full-time	50 Participants n=93 Participants	51 Participants n=4 Participants	101 Participants n=27 Participants
Employment situation Working part-time	15 Participants n=93 Participants	13 Participants n=4 Participants	28 Participants n=27 Participants
Employment situation Student (not working)	4 Participants n=93 Participants	1 Participants n=4 Participants	5 Participants n=27 Participants
Employment situation Other employment status	5 Participants n=93 Participants	10 Participants n=4 Participants	15 Participants n=27 Participants
Low Back Pain Classification Rotation	42 Participants n=93 Participants	40 Participants n=4 Participants	82 Participants n=27 Participants
Low Back Pain Classification Rotation with flexion	1 Participants n=93 Participants	3 Participants n=4 Participants	4 Participants n=27 Participants
Low Back Pain Classification Rotation with extension	31 Participants n=93 Participants	32 Participants n=4 Participants	63 Participants n=27 Participants
Duration of Low Back Pain	7.0 years n=93 Participants	7.0 years n=4 Participants	7.0 years n=27 Participants
Symptoms only in the back	58 Participants n=93 Participants	54 Participants n=4 Participants	112 Participants n=27 Participants
Fear-Avoidance Beliefs Questionnaire - Physical Activity Subscale Score	14.7 units on a scale STANDARD_DEVIATION 6.1 • n=93 Participants	14.1 units on a scale STANDARD_DEVIATION 5.1 • n=4 Participants	14.4 units on a scale STANDARD_DEVIATION 5.6 • n=27 Participants
Fear-Avoidance Beliefs Questionnaire - Work Subscale Score	10.9 units on a scale STANDARD_DEVIATION 8.4 • n=93 Participants	11.8 units on a scale STANDARD_DEVIATION 9.0 • n=4 Participants	11.4 units on a scale STANDARD_DEVIATION 8.7 • n=27 Participants
Modified Oswestry Disability Questionnaire	32.3 units on a scale STANDARD_DEVIATION 10.2 • n=93 Participants	32.6 units on a scale STANDARD_DEVIATION 9.4 • n=4 Participants	32.4 units on a scale STANDARD_DEVIATION 9.8 • n=27 Participants
NRS average pain prior 7 days	4.7 units on a scale STANDARD_DEVIATION 1.9 • n=93 Participants	4.7 units on a scale STANDARD_DEVIATION 1.5 • n=4 Participants	4.7 units on a scale STANDARD_DEVIATION 1.7 • n=27 Participants
NRS worst pain, prior 7 days	6.3 units on a scale STANDARD_DEVIATION 2 • n=93 Participants	6.9 units on a scale STANDARD_DEVIATION 1.6 • n=4 Participants	6.6 units on a scale STANDARD_DEVIATION 1.8 • n=27 Participants

PRIMARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: The 10-item Modified Oswestry Disability Questionnaire is a disease-specific measure that provides an index of a participant's perceived low back pain-related functional limitation.

Procedure: Participants will answer each of the 10 questions by placing a mark in the one box that best describes his current condition. Since a participant may feel that 2 of the statements describe his condition, he is instructed to mark only the box that most closely describes his current condition.

Scoring: Each item is given a value from 0-5. The total score is the sum of all questions divided by 50, multiplied by 100 to get a percent. 100 represents the highest level of limitation.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Modified Oswestry Disability Questionnaire (0-100%) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	32.3 score on a scale Standard Deviation 10.2	32.6 score on a scale Standard Deviation 9.4
Change in Modified Oswestry Disability Questionnaire (0-100%) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	12.8 score on a scale Standard Deviation 10.7	21.2 score on a scale Standard Deviation 10.7

PRIMARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: The 10-item Modified Oswestry Disability Questionnaire is a disease-specific measure that provides an index of a participant's perceived low back pain-related functional limitation.

Procedure: Participants will answer each of the 10 questions by placing a mark in the one box that best describes his current condition. Since a participant may feel that 2 of the statements describe his condition, he is instructed to mark only the box that most closely describes his current condition.

Scoring: Each item is given a value from 0-5. The total score is the sum of all questions divided by 50, multiplied by 100 to get a percent. 100 represents the highest level of limitation.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Modified Oswestry Disability Questionnaire (0-100%) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	12.8 score on a scale Standard Deviation 10.7	21.2 score on a scale Standard Deviation 10.7
Change in Modified Oswestry Disability Questionnaire (0-100%) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	12.0 score on a scale Standard Deviation 12.6	18.2 score on a scale Standard Deviation 10.5

PRIMARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: The 10-item Modified Oswestry Disability Questionnaire is a disease-specific measure that provides an index of a participant's perceived low back pain-related functional limitation.

Procedure: Participants will answer each of the 10 questions by placing a mark in the one box that best describes his current condition. Since a participant may feel that 2 of the statements describe his condition, he is instructed to mark only the box that most closely describes his current condition.

Scoring: Each item is given a value from 0-5. The total score is the sum of all questions divided by 50, multiplied by 100 to get a percent. 100 represents the highest level of limitation.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Modified Oswestry Disability Questionnaire (0-100%) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12	10.8 score on a scale Standard Deviation 11.3	16.7 score on a scale Standard Deviation 11.3
Change in Modified Oswestry Disability Questionnaire (0-100%) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6	12.0 score on a scale Standard Deviation 12.6	18.2 score on a scale Standard Deviation 10.5

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to give the therapist information on the intensity of a participant's LBP symptoms.

Procedure: Participants will rate their LBP symptoms on a numeric scale of 0-10 where 0 represents no symptoms and 10 represents symptoms as bad as can be. They will rate their average symptoms over the prior 7 days, and worst symptoms over the prior 7 days.

Scoring: The score for each item is the rating the participant provides for each symptom category (average and worst).

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Numeric Pain Rating Scale (0-10) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline (Average)	4.7 units on a scale Standard Deviation 1.9	4.7 units on a scale Standard Deviation 1.5
Change in Numeric Pain Rating Scale (0-10) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment (Average)	1.4 units on a scale Standard Deviation 1.1	2.1 units on a scale Standard Deviation 1.2
Change in Numeric Pain Rating Scale (0-10) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline (Worst)	6.3 units on a scale Standard Deviation 2.0	6.9 units on a scale Standard Deviation 1.6
Change in Numeric Pain Rating Scale (0-10) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment (Worst)	2.7 units on a scale Standard Deviation 1.7	4.0 units on a scale Standard Deviation 1.9

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to give the therapist information on the intensity of a participant's LBP symptoms.

Procedure: Participants will rate their LBP symptoms on a numeric scale of 0-10 where 0 represents no symptoms and 10 represents symptoms as bad as can be. They will rate their average symptoms over the prior 7 days, and worst symptoms over the prior 7 days.

Scoring: The score for each item is the rating the participant provides for each symptom category (average and worst).

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Numeric Pain Rating Scale (0-10) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6 (Worst)	2.9 units on a scale Standard Deviation 2.2	3.8 units on a scale Standard Deviation 2.2
Change in Numeric Pain Rating Scale (0-10) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment (Average)	1.4 units on a scale Standard Deviation 1.1	2.1 units on a scale Standard Deviation 1.2
Change in Numeric Pain Rating Scale (0-10) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6 (Average)	2.0 units on a scale Standard Deviation 1.8	2.6 units on a scale Standard Deviation 1.8
Change in Numeric Pain Rating Scale (0-10) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment (Worst)	2.7 units on a scale Standard Deviation 1.7	4.0 units on a scale Standard Deviation 1.9

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to give the therapist information on the intensity of a participant's LBP symptoms.

Procedure: Participants will rate their LBP symptoms on a numeric scale of 0-10 where 0 represents no symptoms and 10 represents symptoms as bad as can be. They will rate their average symptoms over the prior 7 days, and worst symptoms over the prior 7 days.

Scoring: The score for each item is the rating the participant provides for each symptom category (average and worst).

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Numeric Pain Rating Scale (0-10) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12 (Average)	1.8 units on a scale Standard Deviation 1.9	2.6 units on a scale Standard Deviation 2.0
Change in Numeric Pain Rating Scale (0-10) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6 (Worst)	2.9 units on a scale Standard Deviation 2.2	3.8 units on a scale Standard Deviation 2.2
Change in Numeric Pain Rating Scale (0-10) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12 (Worst)	2.8 units on a scale Standard Deviation 2.3	3.9 units on a scale Standard Deviation 2.5
Change in Numeric Pain Rating Scale (0-10) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6 (Average)	2.0 units on a scale Standard Deviation 1.8	2.6 units on a scale Standard Deviation 1.8

SECONDARY outcome

Timeframe: Baseline, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to give the therapist information about the history of a participant's LBP flare-ups in the past 6 months.

Definition: A flare-up is an increase in symptoms of at least 2 points on the NRS above a person's typical low back pain and lasts for at least 2 consecutive days Procedure: Participants will fill in information on how many acute flare-ups they have had over the past 6 months.

Scoring: The score will be the number the participant provides for the number of acute flare-ups over the last 6 months.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Number of Acute Flare-ups of Low Back Pain (#) in Past 6 Months, From Baseline to 6 Months After Initial Intervention Phase Baseline	7.1 acute flare-ups Standard Deviation 7.6	9.8 acute flare-ups Standard Deviation 11.9
Change in Number of Acute Flare-ups of Low Back Pain (#) in Past 6 Months, From Baseline to 6 Months After Initial Intervention Phase Follow-Up Month 6	2.0 acute flare-ups Standard Deviation 3.3	4.2 acute flare-ups Standard Deviation 8.2

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to give the therapist information about the history of a participant's LBP flare-ups in the past 6 months.

Definition: A flare-up is an increase in symptoms of at least 2 points on the NRS above a person's typical low back pain and lasts for at least 2 consecutive days Procedure: Participants will fill in information on how many acute flare-ups they have had over the past 6 months.

Scoring: The score will be the number the participant provides for the number of acute flare-ups over the last 6 months.

Outcome measures

Measure	Motor Skill Training n=67 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=64 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Number of Acute Flare-ups of Low Back Pain (#) in Past 6 Months, From 6 Months After the Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6	2.0 acute flare-ups Standard Deviation 3.3	4.2 acute flare-ups Standard Deviation 8.2
Change in Number of Acute Flare-ups of Low Back Pain (#) in Past 6 Months, From 6 Months After the Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12	1.3 acute flare-ups Standard Deviation 1.8	2.0 acute flare-ups Standard Deviation 2.8

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to provide general information on the use of medication for a participant's LBP.

Procedure: Participants will answer each question by marking if they are taking non-prescription medication and prescription medication for their LBP. Reported as number of participants currently using medication for LBP.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Current Medication Use for Low Back Pain (Number of Participants Currently Using Medication) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	50 Participants	47 Participants
Change in Current Medication Use for Low Back Pain (Number of Participants Currently Using Medication) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	21 Participants	31 Participants

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to provide general information on the use of medication for a participant's LBP.

Procedure: Participants will answer each question by marking if they are taking non-prescription medication and prescription medication for their LBP. Reported as number of participants currently using medication for LBP.

Outcome measures

Measure	Motor Skill Training n=70 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Current Medication Use for Low Back Pain (Number of Participants Currently Using Medication) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	21 Participants	31 Participants
Change in Current Medication Use for Low Back Pain (Number of Participants Currently Using Medication) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	27 Participants	29 Participants

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to provide general information on the use of medication for a participant's LBP.

Procedure: Participants will answer each question by marking if they are taking non-prescription medication and prescription medication for their LBP. Reported as number of participants currently using medication for LBP.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=66 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Current Medication Use for Low Back Pain (Number of Participants Currently Using Medication) From 6 Months After Completion of Initial Intervention Phase to 12 Months After Completion of Initial Intervention Phase Follow-Up Month 6	27 Participants	29 Participants
Change in Current Medication Use for Low Back Pain (Number of Participants Currently Using Medication) From 6 Months After Completion of Initial Intervention Phase to 12 Months After Completion of Initial Intervention Phase Follow-Up Month 12	23 Participants	25 Participants

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess the number of days a participant has been kept from his usual activities (work, school or housework) because of LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Reported as the number of participants who reported absenteeism from usual activities over the past 4 weeks.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Absenteeism From Usual Activities Due to Low Back Pain (Number of Participants Who Report Absenteeism) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	42 Participants	47 Participants
Change in Absenteeism From Usual Activities Due to Low Back Pain (Number of Participants Who Report Absenteeism) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	11 Participants	29 Participants

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess the number of days a participant has been kept from his usual activities (work, school or housework) because of LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Reported as the number of participants who reported absenteeism from usual activities over the past 4 weeks.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Absenteeism From Usual Activities Due to Low Back Pain (Number of Participants Who Report Absenteeism) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	11 Participants	29 Participants
Change in Absenteeism From Usual Activities Due to Low Back Pain (Number of Participants Who Report Absenteeism) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	9 Participants	11 Participants

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess the number of days a participant has been kept from his usual activities (work, school or housework) because of LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Reported as the number of participants who reported absenteeism from usual activities over the past 4 weeks.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Absenteeism From Usual Activities Due to Low Back Pain (Number of Participants Who Report Absenteeism) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6	9 Participants	11 Participants
Change in Absenteeism From Usual Activities Due to Low Back Pain (Number of Participants Who Report Absenteeism) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12	11 Participants	12 Participants

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess how a participant's LBP affected his participation in usual activities and the impact of LBP on his ability to do his job over the past 4 weeks.

Scoring: A Work Impairment Score (WIS) is calculated as the sum of answers on the questions regarding how LBP has affected job ability over the past 4 weeks. Each of the WIS questions is ranked on a 5-point Likert scale. All scores are 1-5, with questions 2, 5, 6, 8, and 10 reverse scored (5-1). The score ranges from 10-50 with 50 indicating the highest degree of impairment.

Outcome measures

Measure	Motor Skill Training n=66 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=63 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Stanford Presenteeism Scale (Work Impairment Score: 10-50) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	20.3 score on a scale Standard Deviation 5.3	19.9 score on a scale Standard Deviation 6.2
Change in Stanford Presenteeism Scale (Work Impairment Score: 10-50) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	17.4 score on a scale Standard Deviation 4.6	18.3 score on a scale Standard Deviation 5.2

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess how a participant's LBP affected his participation in usual activities and the impact of LBP on his ability to do his job over the past 4 weeks.

Scoring: A Work Impairment Score (WIS) is calculated as the sum of answers on the questions regarding how LBP has affected job ability over the past 4 weeks. Each of the WIS questions is ranked on a 5-point Likert scale. All scores are 1-5, with questions 2, 5, 6, 8, and 10 reverse scored (5-1). The score ranges from 10-50 with 50 indicating the highest degree of impairment.

Outcome measures

Measure	Motor Skill Training n=59 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=59 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Stanford Presenteeism Scale (Work Impairment Score: 10-50) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	17.4 score on a scale Standard Deviation 4.6	18.3 score on a scale Standard Deviation 5.2
Change in Stanford Presenteeism Scale (Work Impairment Score: 10-50) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	15.9 score on a scale Standard Deviation 5.6	16.5 score on a scale Standard Deviation 5.3

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess how a participant's LBP affected his participation in usual activities and the impact of LBP on his ability to do his job over the past 4 weeks.

Scoring: A Work Impairment Score (WIS) is calculated as the sum of answers on the questions regarding how LBP has affected job ability over the past 4 weeks. Each of the WIS questions is ranked on a 5-point Likert scale. All scores are 1-5, with questions 2, 5, 6, 8, and 10 reverse scored (5-1). The score ranges from 10-50 with 50 indicating the highest degree of impairment.

Outcome measures

Measure	Motor Skill Training n=59 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=59 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Stanford Presenteeism Scale (Work Impairment Score: 10-50) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6	15.9 score on a scale Standard Deviation 5.6	16.5 score on a scale Standard Deviation 5.3
Change in Stanford Presenteeism Scale (Work Impairment Score: 10-50) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12	15.4 score on a scale Standard Deviation 5.1	16.7 score on a scale Standard Deviation 6.0

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess information about a participant's mental and physical health, and how well he is able to do his usual activities.

Procedure: Participants will answer each question by marking the answer as indicated. If participants are unsure how to answer a question, they are instructed to choose the best answer they can.

Scoring: Using a scoring application, the SF-36 provides 8 scales: a Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional, and a Mental Health score. The scores are combined to provide a Physical Component (PCS) and Mental Component (MCS) Summary score. For the PCS and the MCS, norm-based scores are scaled and normalized to have a mean of 50 and a standard deviation of 10 based on the 1998 population norms. Higher scores indicate better health.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in 36-Item Short Form Health Survey (SF-36) Physical Component Summary Score From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	43.2 T-scores Standard Deviation 6.6	40.8 T-scores Standard Deviation 6.9
Change in 36-Item Short Form Health Survey (SF-36) Physical Component Summary Score From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	50.8 T-scores Standard Deviation 6.5	46.3 T-scores Standard Deviation 7.0

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess information about a participant's mental and physical health, and how well he is able to do his usual activities.

Procedure: Participants will answer each question by marking the answer as indicated. If participants are unsure how to answer a question, they are instructed to choose the best answer they can.

Scoring: Using a scoring application, the SF-36 provides 8 scales: a Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional, and a Mental Health score. The scores are combined to provide a Physical Component (PCS) and Mental Component (MCS) Summary score. For the PCS and the MCS, norm-based scores are scaled and normalized to have a mean of 50 and a standard deviation of 10 based on the 1998 population norms. Higher scores indicate better health.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in 36-Item Short Form Health Survey (SF-36) Physical Component Summary Score From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	50.8 T-scores Standard Deviation 6.5	46.3 T-scores Standard Deviation 7.0
Change in 36-Item Short Form Health Survey (SF-36) Physical Component Summary Score From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	50.9 T-scores Standard Deviation 6.6	47.8 T-scores Standard Deviation 7.4

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess information about a participant's mental and physical health, and how well he is able to do his usual activities.

Procedure: Participants will answer each question by marking the answer as indicated. If participants are unsure how to answer a question, they are instructed to choose the best answer they can.

Scoring: Using a scoring application, the SF-36 provides 8 scales: a Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional, and a Mental Health score. The scores are combined to provide a Physical Component (PCS) and Mental Component (MCS) Summary score. For the PCS and the MCS, norm-based scores are scaled and normalized to have a mean of 50 and a standard deviation of 10 based on the 1998 population norms. Higher scores indicate better health.

Outcome measures

Measure	Motor Skill Training n=66 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=64 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in 36-Item Short Form Health Survey (SF-36) Physical Component Summary Score From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6	50.9 T-scores Standard Deviation 6.6	47.8 T-scores Standard Deviation 7.4
Change in 36-Item Short Form Health Survey (SF-36) Physical Component Summary Score From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12	51.2 T-scores Standard Deviation 8.0	48.3 T-scores Standard Deviation 7.4

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess information about a participant's mental and physical health, and how well he is able to do his usual activities.

Procedure: Participants will answer each question by marking the answer as indicated. If participants are unsure how to answer a question, they are instructed to choose the best answer they can.

Scoring: Using a scoring application, the SF-36 provides 8 scales: a Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional, and a Mental Health score. The scores are combined to provide a Physical Component (PCS) and Mental Component (MCS) Summary score. For the PCS and the MCS, norm-based scores are scaled and normalized to have a mean of 50 and a standard deviation of 10 based on the 1998 population norms. Higher scores indicate better health.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in 36-Item Short Form Health Survey (SF-36) Mental Component Summary Score From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	49.2 T-scores Standard Deviation 11.6	52.1 T-scores Standard Deviation 9.3
Change in 36-Item Short Form Health Survey (SF-36) Mental Component Summary Score From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	50.7 T-scores Standard Deviation 8.6	51.0 T-scores Standard Deviation 11.6

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess information about a participant's mental and physical health, and how well he is able to do his usual activities.

Procedure: Participants will answer each question by marking the answer as indicated. If participants are unsure how to answer a question, they are instructed to choose the best answer they can.

Scoring: Using a scoring application, the SF-36 provides 8 scales: a Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional, and a Mental Health score. The scores are combined to provide a Physical Component (PCS) and Mental Component (MCS) Summary score. For the PCS and the MCS, norm-based scores are scaled and normalized to have a mean of 50 and a standard deviation of 10 based on the 1998 population norms. Higher scores indicate better health.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in 36-Item Short Form Health Survey (SF-36) Mental Component Summary Score From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	50.7 T-scores Standard Deviation 8.6	51.0 T-scores Standard Deviation 11.6
Change in 36-Item Short Form Health Survey (SF-36) Mental Component Summary Score From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	49.6 T-scores Standard Deviation 10.5	50.8 T-scores Standard Deviation 10.4

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess information about a participant's mental and physical health, and how well he is able to do his usual activities.

Procedure: Participants will answer each question by marking the answer as indicated. If participants are unsure how to answer a question, they are instructed to choose the best answer they can.

Scoring: Using a scoring application, the SF-36 provides 8 scales: a Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional, and a Mental Health score. The scores are combined to provide a Physical Component (PCS) and Mental Component (MCS) Summary score. For the PCS and the MCS, norm-based scores are scaled and normalized to have a mean of 50 and a standard deviation of 10 based on the 1998 population norms. Higher scores indicate better health.

Outcome measures

Measure	Motor Skill Training n=66 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=64 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in 36-Item Short Form Health Survey (SF-36) Mental Component Summary Score From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6	49.6 T-scores Standard Deviation 10.5	50.8 T-scores Standard Deviation 10.4
Change in 36-Item Short Form Health Survey (SF-36) Mental Component Summary Score From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12	50.4 T-scores Standard Deviation 10.3	50.3 T-scores Standard Deviation 11.5

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to provide general information on the use of additional treatments for a participant's LBP.

Health Professional Care Seeking Procedure: Participants will answer each question by marking yes or no for a list of other healthcare professionals they are seeing for treatment of their LBP.

Equipment Use Procedure: Participants will answer each question by marking yes or no for a list of equipment they are using to treat their LBP.

Scoring: Reported as the number of participants seeking care from health professionals for LBP or using equipment for LBP.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline (Care Seeking)	35 Participants	29 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment (Care Seeking)	7 Participants	6 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline (Equipment Use)	66 Participants	65 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment (Equipment Use)	62 Participants	48 Participants

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to provide general information on the use of additional treatments for a participant's LBP.

Health Professional Care Seeking Procedure: Participants will answer each question by marking yes or no for a list of other healthcare professionals they are seeing for treatment of their LBP.

Equipment Use Procedure: Participants will answer each question by marking yes or no for a list of equipment they are using to treat their LBP.

Scoring: Reported as the number of participants seeking care from health professionals for LBP or using equipment for LBP.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment (Care Seeking)	7 Participants	6 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6 (Care Seeking)	13 Participants	13 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment (Equipment Use)	62 Participants	48 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6 (Equipment Use)	33 Participants	29 Participants

SECONDARY outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to provide general information on the use of additional treatments for a participant's LBP.

Health Professional Care Seeking Procedure: Participants will answer each question by marking yes or no for a list of other healthcare professionals they are seeing for treatment of their LBP.

Equipment Use Procedure: Participants will answer each question by marking yes or no for a list of equipment they are using to treat their LBP.

Scoring: Reported as the number of participants seeking care from health professionals for LBP or using equipment for LBP.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6 (care seeking)	13 Participants	13 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12 (care seeking)	8 Participants	11 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 6 (equipment use)	33 Participants	29 Participants
Change in Use of Other Low Back Pain-related Treatments (Health Professional Care Seeking or Equipment Use (# of Participants)) From 6 Months After Initial Intervention Phase to 12 Months After Initial Intervention Phase Follow-Up Month 12 (equipment use)	28 Participants	30 Participants

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire assesses information about how satisfied a participant feels with the physical therapist and treatment he was provided.

Procedure: Participants will answer each question by marking the answer as indicated. They may only check off one answer per item.

Scoring: Each question is ranked on a 5-point Likert scale. All scores are 1-5, with questions 1, 3, 4, 8, 9, 10 and 13 reverse scored (5-1). The total score is the sum of all of the answers (15-75) with higher scores indicating more satisfaction with care.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Satisfaction With Care (15-75 Points)	68.8 score on a scale Standard Deviation 0.9	61.4 score on a scale Standard Deviation 0.9

SECONDARY outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: These are laboratory measures of (1) movement of the lumbar region, hips and knees or (2) static alignment of the lumbar region during functional activities. Procedures: Angular data is quantified based on data from retro-reflective markers that are tracked with a 3-dimensional video system while the person performs an activity. Coordinate data from the video system is processed to provide quantification of movement or alignment. The variables of interest are (1) angular excursion in the first 50% of the descent phase for each region or joint during picking up an object and (2) lumbar curvature angle for preferred sitting. For movement, smaller numbers from baseline to post-treatment represent decreased movement of a region or joint. For alignment, larger negative numbers from baseline to post-treatment represent a more extended lumbar region alignment. Measures are obtained at baseline and immediately after a 6-week intervention phase.

Outcome measures

Measure	Motor Skill Training n=76 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=77 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline: Knee joint excursion	11.08 Angle in degrees Interval 8.04 to 14.11	8.86 Angle in degrees Interval 5.81 to 11.9
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Post-intervention: Lumbar region curvature	-7.51 Angle in degrees Interval -9.7 to -5.33	-6.45 Angle in degrees Interval -8.52 to -4.38
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline: Lumbar region excursion	11.32 Angle in degrees Interval 10.36 to 12.29	11.23 Angle in degrees Interval 10.28 to 12.17
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Post-intervention: Lumbar region	9.17 Angle in degrees Interval 8.33 to 10.0	11.05 Angle in degrees Interval 9.94 to 12.16
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline: Hip joint excursion	21.17 Angle in degrees Interval 19.18 to 23.16	20.84 Angle in degrees Interval 18.78 to 22.9
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Post-intervention: Hip joint excursion	31.98 Angle in degrees Interval 29.84 to 34.13	20.36 Angle in degrees Interval 18.46 to 22.25
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Post-intervention: Knee joint excursion	30.10 Angle in degrees Interval 26.96 to 33.25	9.69 Angle in degrees Interval 6.15 to 13.24
Change in Kinematics During Functional Activities (Degrees) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline: Lumbar region curvature	-5.91 Angle in degrees Interval -7.91 to -3.88	-3.18 Angle in degrees Interval -5.09 to -1.27

SECONDARY outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: These are laboratory measures of (1) movement of the lumbar region, hips and knees or (2) static alignment of the lumbar region during functional activities. Procedures: Angular data is quantified based on data from retro-reflective markers that are tracked with a 3-dimensional video system while the person performs an activity. Coordinate data from the video system is processed to provide quantification of movement or alignment. The variables of interest are (1) angular excursion in the first 50% of the descent phase for each region or joint during picking up an object and (2) lumbar curvature angle for preferred sitting. For movement, smaller numbers from baseline to post-treatment represent decreased movement of a region or joint. For alignment, larger negative numbers from baseline to post-treatment represent a more extended lumbar region alignment. Measures are obtained after a 6 week intervention phase and 6 months after intervention.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase Post-intervention: Knee joint excursion	30.10 Angle in degrees Interval 26.96 to 33.25	9.69 Angle in degrees Interval 6.15 to 13.2
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase Post-intervention: Lumbar excursion	9.17 Angle in degrees Interval 8.33 to 10.0	11.05 Angle in degrees Interval 9.94 to 12.16
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase 6 months post-intervention: Lumbar excursion	8.63 Angle in degrees Interval 7.71 to 9.55	10.84 Angle in degrees Interval 9.73 to 11.96
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase Post-intervention: Hip joint excursion	31.98 Angle in degrees Interval 29.84 to 34.13	20.36 Angle in degrees Interval 18.46 to 22.25
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase 6 months post-intervention: Hip joint excursion	30.03 Angle in degrees Interval 27.7 to 32.35	20.08 Angle in degrees Interval 18.39 to 21.78
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase 6 months post intervention: Knee joint excursion	26.90 Angle in degrees Interval 23.83 to 29.97	9.81 Angle in degrees Interval 6.43 to 13.2
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase Post-intervention: Lumbar curvature	-7.51 Angle in degrees Interval -9.7 to -5.33	-6.45 Angle in degrees Interval -8.52 to -4.38
Change in Kinematics During Functional Activities (Degrees) From Completion of Initial 6 Week Intervention Phase to 6 Months After Intervention Phase 6 months post-intervention: Lumbar curvature	-5.43 Angle in degrees Interval -7.63 to -3.24	-5.89 Angle in degrees Interval -7.79 to -3.99

OTHER_PRE_SPECIFIED outcome

Timeframe: completion of initial 6 week intervention phase

Population: Data available at this time point

Background/Purpose: This questionnaire is designed to provide information about how often a participant performs his treatment as it was prescribed.

Procedure: Participants will use a VAS to indicate for each day the percentage of the treatment they were able to perform as prescribed. At each clinic visit the therapist will ask the participant to provide an estimate of the average percentage of the treatment he was able to perform as prescribed in the interval of time between 2 clinic visits.

Scoring: Average adherence is calculated by averaging the participants' daily adherence. Scores range from 0-100%. Higher values indicate higher adherence to treatment.

Outcome measures

Measure	Motor Skill Training n=71 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=72 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Adherence to Home Program (0-100%) at Completion of Initial 6 Week Intervention Phase	83 percentage of adherence to home program Standard Deviation 14	90 percentage of adherence to home program Standard Deviation 15

OTHER_PRE_SPECIFIED outcome

Timeframe: 6 months after initial intervention phase

Population: Data available at this time point

Background/Purpose: This questionnaire is designed to provide information about how often a participant performs his treatment as it was prescribed.

Procedure: Participants will use a VAS to indicate an average percent adherence to performance of the treatment as prescribed over the past month.

Scoring: Value (percentage of treatment performed) provided by the participant on each monthly survey. Scores range from 0-100%. Higher values indicate higher adherence to treatment.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Adherence to Home Program (0-100%) at 6 Months After Completion of Initial Intervention Phase	70 percentage of adherence to home program Standard Deviation 21	42 percentage of adherence to home program Standard Deviation 31

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 months after initial intervention phase

Population: Data available at this time point

Background/Purpose: This questionnaire is designed to provide information about how often a participant performs his treatment as it was prescribed.

Procedure: Participants will use a VAS to indicate an average percent adherence to performance of the treatment as prescribed over the past month.

Scoring: Value (percentage of treatment performed) provided by the participant on each monthly survey. Scores range from 0-100%. Higher values indicate higher adherence to treatment.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=65 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Adherence to Home Program (0-100%) at 12 Months After Initial Intervention Phase	66 percentage of adherence to home program Standard Deviation 21	52 percentage of adherence to home program Standard Deviation 35

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess a participant's fear of pain and beliefs about how work and physical activity affect his LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Each question is ranked on a 7-point Likert scale (0-6). Higher scores indicate higher fear-avoidance. Two subscale scores are calculated. The physical activity subscale score (FABQ-PA) is the sum of questions 2, 3, 4, and 5 and ranges from 0-24. The work subscale score (FABQ-W) is the sum of items 6, 7, 9, 10, 11, 12, and 15 and ranges from 0-42.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Fear-Avoidance Beliefs Questionnaire Work Subscale Score (0-42 Points) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	10.9 score on a scale Standard Deviation 8.4	11.8 score on a scale Standard Deviation 9.0
Change in Fear-Avoidance Beliefs Questionnaire Work Subscale Score (0-42 Points) From Baseline to Completion of Initial 6 Week Intervention Phase Post-Treatment	7.7 score on a scale Standard Deviation 7.1	10.9 score on a scale Standard Deviation 9.5

OTHER_PRE_SPECIFIED outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess a participant's fear of pain and beliefs about how work and physical activity affect his LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Each question is ranked on a 7-point Likert scale (0-6). Higher scores indicate higher fear-avoidance. Two subscale scores are calculated. The physical activity subscale score (FABQ-PA) is the sum of questions 2, 3, 4, and 5 and ranges from 0-24. The work subscale score (FABQ-W) is the sum of items 6, 7, 9, 10, 11, 12, and 15 and ranges from 0-42.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Fear-Avoidance Beliefs Questionnaire Work Subscale Score (0-42 Points) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	7.7 score on a scale Standard Deviation 7.1	10.9 score on a scale Standard Deviation 9.5
Change in Fear-Avoidance Beliefs Questionnaire Work Subscale Score (0-42 Points) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	7.2 score on a scale Standard Deviation 8.2	9.0 score on a scale Standard Deviation 8.7

OTHER_PRE_SPECIFIED outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data for 12 months after the initial intervention phase were not collected. The decision not to collect 12 month data was made prior to finalization of the protocol and participant enrollment.

Background/Purpose: This questionnaire is designed to assess a participant's fear of pain and beliefs about how work and physical activity affect his LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Each question is ranked on a 7-point Likert scale (0-6). Higher scores indicate higher fear-avoidance. Two subscale scores are calculated. The physical activity subscale score (FABQ-PA) is the sum of questions 2, 3, 4, and 5 and ranges from 0-24. The work subscale score (FABQ-W) is the sum of items 6, 7, 9, 10, 11, 12, and 15 and ranges from 0-42.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess a participant's fear of pain and beliefs about how work and physical activity affect his LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Each question is ranked on a 7-point Likert scale (0-6). Higher scores indicate higher fear-avoidance. Two subscale scores are calculated. The physical activity subscale score (FABQ-PA) is the sum of questions 2, 3, 4, and 5 and ranges from 0-24. The work subscale score (FABQ-W) is the sum of items 6, 7, 9, 10, 11, 12, and 15 and ranges from 0-42.

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Fear-Avoidance Beliefs Questionnaire Physical Activity Subscale Score (0-24 Points) From Baseline to Completion of Initial 6 Week Intervention Phase Baseline	14.7 score on a scale Standard Deviation 6.1	14.1 score on a scale Standard Deviation 5.1
Change in Fear-Avoidance Beliefs Questionnaire Physical Activity Subscale Score (0-24 Points) From Baseline to Completion of Initial 6 Week Intervention Phase Follow-Up Month 6	11.4 score on a scale Standard Deviation 5.9	11.6 score on a scale Standard Deviation 5.3

OTHER_PRE_SPECIFIED outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: Data available at the time points

Background/Purpose: This questionnaire is designed to assess a participant's fear of pain and beliefs about how work and physical activity affect his LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Each question is ranked on a 7-point Likert scale (0-6). Higher scores indicate higher fear-avoidance. Two subscale scores are calculated. The physical activity subscale score (FABQ-PA) is the sum of questions 2, 3, 4, and 5 and ranges from 0-24. The work subscale score (FABQ-W) is the sum of items 6, 7, 9, 10, 11, 12, and 15 and ranges from 0-42.

Outcome measures

Measure	Motor Skill Training n=68 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=67 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Change in Fear-Avoidance Beliefs Questionnaire Physical Activity Subscale Score (0-24 Points) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Post-Treatment	11.4 score on a scale Standard Deviation 5.9	11.6 score on a scale Standard Deviation 5.3
Change in Fear-Avoidance Beliefs Questionnaire Physical Activity Subscale Score (0-24 Points) From Completion of Initial 6 Week Intervention Phase to 6 Months After Initial Intervention Phase Follow-Up Month 6	11.0 score on a scale Standard Deviation 5.8	11.4 score on a scale Standard Deviation 5.5

OTHER_PRE_SPECIFIED outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: Data for 12 months after the initial intervention phase were not collected. The decision not to collect 12 month data was made prior to finalization of the protocol and participant enrollment.

Background/Purpose: This questionnaire is designed to assess a participant's fear of pain and beliefs about how work and physical activity affect his LBP.

Procedure: Participants will answer each question by marking the answer as indicated.

Scoring: Each question is ranked on a 7-point Likert scale (0-6). Higher scores indicate higher fear-avoidance. Two subscale scores are calculated. The physical activity subscale score (FABQ-PA) is the sum of questions 2, 3, 4, and 5 and ranges from 0-24. The work subscale score (FABQ-W) is the sum of items 6, 7, 9, 10, 11, 12, and 15 and ranges from 0-42.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline

Background/Purpose: This questionnaire is designed to provide information about a participant's treatment preferences and the participant's perceptions of four attributes of each treatment: effectiveness, acceptability, suitability/appropriateness, and convenience. The questionnaire is modified from a preference questionnaire designed by Sidani et al to reflect the treatments provided in the trial.

Procedure: The two treatment descriptions will be given in a random order to each participant.

Scoring: The four treatment attributes (effectiveness, acceptability, suitability/appropriateness, and convenience) will be rated on a 5-point Likert scale (0-4). The anchors are not at all (rating=0) and very much (rating=4).

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Treatment Preference Assessment Measure, Effectiveness Subscale (0-4 Points) Effectiveness of Motor Skill Training	2.28 units on a scale Standard Deviation 1.14	2.36 units on a scale Standard Deviation 1.00
Treatment Preference Assessment Measure, Effectiveness Subscale (0-4 Points) Effectiveness of Strength and Flexibility Exercise	3.19 units on a scale Standard Deviation 0.81	2.92 units on a scale Standard Deviation 0.82

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline

Population: Data available at this time point

Background/Purpose: This questionnaire is designed to provide information about a participant's treatment preferences and the participant's perceptions of four attributes of each treatment: effectiveness, acceptability, suitability/appropriateness, and convenience. The questionnaire is modified from a preference questionnaire designed by Sidani et al to reflect the treatments provided in the trial.

Procedure: The two treatment descriptions will be given in a random order to each participant.

Scoring: The four treatment attributes (effectiveness, acceptability, suitability/appropriateness, and convenience) will be rated on a 5-point Likert scale (0-4). The anchors are not at all (rating=0) and very much (rating=4).

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Treatment Preference Assessment Measure, Acceptability Subscale (0-4 Points) Acceptability of Strength and Flexibility Exercise	3.37 units on a scale Standard Deviation 0.69	3.21 units on a scale Standard Deviation 0.70
Treatment Preference Assessment Measure, Acceptability Subscale (0-4 Points) Acceptability of Motor Skill Training	2.66 units on a scale Standard Deviation 1.09	2.72 units on a scale Standard Deviation 0.97

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline

Background/Purpose: This questionnaire is designed to provide information about a participant's treatment preferences and the participant's perceptions of four attributes of each treatment: effectiveness, acceptability, suitability/appropriateness, and convenience. The questionnaire is modified from a preference questionnaire designed by Sidani et al to reflect the treatments provided in the trial.

Procedure: The two treatment descriptions will be given in a random order to each participant.

Scoring: The four treatment attributes (effectiveness, acceptability, suitability/appropriateness, and convenience) will be rated on a 5-point Likert scale (0-4). The anchors are not at all (rating=0) and very much (rating=4).

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Treatment Preference Assessment Measure, Suitability/Appropriateness Subscale (0-4 Points) Suitability of Motor Skill Training	2.43 units on a scale Standard Deviation 1.14	2.48 units on a scale Standard Deviation 1.20
Treatment Preference Assessment Measure, Suitability/Appropriateness Subscale (0-4 Points) Suitability of Strength and Flexibility Exercise	3.31 units on a scale Standard Deviation 0.74	3.15 units on a scale Standard Deviation 0.80

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline

Population: Data available at this time point

Background/Purpose: This questionnaire is designed to provide information about a participant's treatment preferences and the participant's perceptions of four attributes of each treatment: effectiveness, acceptability, suitability/appropriateness, and convenience. The questionnaire is modified from a preference questionnaire designed by Sidani et al to reflect the treatments provided in the trial.

Procedure: The two treatment descriptions will be given in a random order to each participant.

Scoring: The four treatment attributes (effectiveness, acceptability, suitability/appropriateness, and convenience) will be rated on a 5-point Likert scale (0-4). The anchors are not at all (rating=0) and very much (rating=4).

Outcome measures

Measure	Motor Skill Training n=74 Participants The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 Participants The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Treatment Preference Assessment Measure, Convenience Subscale (0-4 Points) Convenience of Motor Skill Training	2.65 units on a scale Standard Deviation 0.96	2.45 units on a scale Standard Deviation 0.96
Treatment Preference Assessment Measure, Convenience Subscale (0-4 Points) Convenience of Strength and Flexibility Exercise	3.01 units on a scale Standard Deviation 0.89	2.76 units on a scale Standard Deviation 0.93

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline, completion of initial 6 week intervention phase

Population: The exploratory economic analyses we proposed to examine direct (medication and health services use and medical equipment) and indirect (absenteeism and presenteeism) health costs are not to be conducted. The decision was based on large budget cuts that limited our ability to financially support the personnel to conduct the analyses

Background/Purpose: These are measures of costs associated with healthcare over the intervention phase. Procedure: Direct health costs will be estimates of the cost of (1) medication using average wholesale price and wholesale acquisition cost and (2) health services and medical equipment using the Medicare allowable cost. Indirect health costs will be estimated using absenteeism and presenteeism measures.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Completion of initial 6 week intervention phase, 6 months after initial intervention phase

Population: The exploratory economic analyses we proposed to examine direct (medication and health services use and medical equipment) and indirect (absenteeism and presenteeism) health costs are not to be conducted. The decision was based on large budget cuts that limited our ability to financially support the personnel to conduct the analyses

Background/Purpose: These are measures of costs associated with healthcare from completion of the initial 6 week intervention phase to 6 months after the initial intervention phase.. Procedure: Direct health costs will be estimates of the cost of (1) medication using average wholesale price and wholesale acquisition cost and (2) health services and medical equipment using the Medicare allowable cost. Indirect health costs will be estimated using absenteeism and presenteeism measures.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: 6 months after initial intervention phase, 12 months after initial intervention phase

Population: The exploratory economic analyses we proposed to examine direct (medication and health services use and medical equipment) and indirect (absenteeism and presenteeism) health costs are not to be conducted. The decision was based on large budget cuts that limited our ability to financially support the personnel to conduct the analyses

Background/Purpose: These are measures of costs associated with healthcare from 6 months after the initial intervention phase to 12 months after the initial intervention phase. Procedure: Direct health costs will be estimates of the cost of (1) medication using average wholesale price and wholesale acquisition cost and (2) health services and medical equipment using the Medicare allowable cost. Indirect health costs will be estimated using absenteeism and presenteeism measures.

Outcome measures

Outcome data not reported

Adverse Events

Motor Skill Training

Serious events: 1 serious events

Other events: 43 other events

Deaths: 0 deaths

Strength and Flexibility Exercise

Serious events: 1 serious events

Other events: 34 other events

Deaths: 0 deaths

Serious adverse events

Measure	Motor Skill Training n=74 participants at risk The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 participants at risk The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Non-Related to Treatment: Ductal Carcinoma	1.4% 1/74 • Number of events 1 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.	0.00% 0/75 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.
Surgical and medical procedures Non-Related to Treatment: Disc Herniation Surgery	0.00% 0/74 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.	1.3% 1/75 • Number of events 1 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.

Other adverse events

Measure	Motor Skill Training n=74 participants at risk The motor skill training condition involves supervised, massed practice of novel, challenging functional activities that are difficult or painful for the participant to perform due to his low back pain. Motor skill training: The participant will assist in selecting both simple and complex functional activities to practice. Difficulty will be graded to match the participant's motor capabilities. Three activities will be practiced per session. Within the practice of activities the training will emphasize 1) contraction of groups of specific trunk muscles, 2) earlier and greater movement of the hip, knee, and/or thoracic spine relative to the lumbar spine, 3) later and less movement of the lumbar spine relative to other regions. Within each activity the conditions of practice will vary based on 1) the participant's ability to perform the activity, and 2) the level of challenge the participant is faced with when performing the activity during his day. Equipment provided as needed.	Strength and Flexibility Exercise n=75 participants at risk The strength and flexibility exercise condition involves performance of 1) strengthening exercises that target all trunk muscles, and 2) flexibility exercises that target all trunk and lower extremity motions. Strength and flexibility exercise: Exercises based on best evidence for effectiveness in people with chronic low back pain will be prescribed. Strengthening exercises will target all trunk muscles. Flexibility exercises will target all trunk and hip motions. All exercises will be performed at the intensity appropriate for the person's musculoskeletal fitness level based on the American College of Sports Medicine guidelines. Difficulty level, frequency, and number of repetitions will be modified based on guidelines described in the literature. Equipment will be provided as needed.
Musculoskeletal and connective tissue disorders Non-Related to Treatment: Worsening of symptoms	50.0% 37/74 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.	33.3% 25/75 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.
Musculoskeletal and connective tissue disorders Related to Treatment: Worsening of symptoms	1.4% 1/74 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.	2.7% 2/75 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.
General disorders Non-Related to Treatment: non-serious	6.8% 5/74 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.	9.3% 7/75 • Study recruitment began in December of 2013 and all study participation ended November of 2017 therefore any adverse event data would be collected between those study time points. Participation for any given individuals was approximately 14 months.

Additional Information

Linda van Dillen, PT, PhD, FAPTA; Research Division Director

Washington University

Phone: 314-286-1427

Email: vandillenl@wustl.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place