Trial Outcomes & Findings for Optimization of Spinal Manipulative Therapy Protocols (NCT NCT02868034)

Last Updated: 2023-05-17

Results Overview

Spinal stiffness is assessed with the VerteTrack device that applies a vertical load along the lumbar spine of a prone participant. The indenter houses a sensor to provide continuous, real-time quantification of spinal deformation in response to a defined load. Stiffness was determined as the ratio of the maximum applied force to the resultant displacement in N/mm. Higher numbers indicate greater amounts of stiffness.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

273 participants

Primary outcome timeframe

Assessed at Phase II Baseline, 4 weeks, 12 weeks. 4 weeks and 12 weeks reported. Phase II baseline values were constrained to be equal to a common overall mean for analyses.

Results posted on

2023-05-17

Participant Flow

Participants were enrolled into Phase I of the study (enrollment - 1 week). After the completion of Phase I participants were randomized to an intervention arm for Phase II (1 week - 12 weeks). Baseline data are provided from the 1-week assessment, which corresponds to the time of randomization and beginning of Phase II.

Participant milestones

Participant milestones
Measure	Phase II - SMT Only Patients receive 2 sessions on SMT during treatment Phase I, no additional treatment in Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. If the subject cannot identify a more painful side the clinician selects a side. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. The clinician notes if a cavitation (ie, a "pop") occurred. If it does, SMT treatment is complete. If no cavitation occurs, the subject is repositioned and SMT is performed again. If no cavitation occurs on the second attempt, the clinician manipulates the opposite side. A maximum of 2 attempts per side is permitted. If no cavitation is noted by that time, SMT treatment is complete. Substitution with a side-posture HVLA technique is allowed if the preferred technique is not possible due to subject preference or comfort.	Phase II - SMT Extended Patients received 2 sessions of SMT in during Phase I, and 6 additional sessions of SMT during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. If the subject cannot identify a more painful side the clinician selects a side. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. The clinician notes if a cavitation (ie, a "pop") occurred. If it does, SMT treatment is complete. If no cavitation occurs, the subject is repositioned and SMT is performed again. If no cavitation occurs on the second attempt, the clinician manipulates the opposite side. A maximum of 2 attempts per side is permitted. If no cavitation is noted by that time, SMT treatment is complete. Substitution with a side-posture HVLA technique is allowed if the preferred technique is not possible due to subject preference or comfort. SMT extended: This treatment involves 6 additional SMT sessions. Each SMT session is conducted as described previously.	Phase II - SMT With Activation Exercises Patients received 2 sessions of SMT during Phase I, and 6 additional sessions of lumbar multifidus activating exercises during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. Substitution with a side-posture HVLA technique is allowed. Activation Exercises: Activation exercises are designed to facilitate use of the lumbar multifidus muscle. Exercises will begin with isometric multifidus contractions in different positions with clinician feedback and exercises to isometrically co-contract the multifidus and deep abdominal muscles. Subjects will also perform lumbar extensor strengthening exercises shown to produce 20%-50% of multifidus maximum voluntary contraction. Subjects will continue to perform isometric exercises throughout treatment. Subjects will perform their prescribed exercises at treatment sessions and will be instructed to perform the exercises daily on other days.	Phase II - SMT With Mobilizing Exercises patients received 2 sessions of SMT during Phase I; and 6 sessions of spinal mobilizing exercises during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. Substitution with a side-posture HVLA technique is allowed. Mobilizing Exercises: Mobilizing exercises will include a program of repeated movements progressing into end-ranges of spinal flexion and/or extension shown in past studies to improve ROM and reduce spinal stiffness. Patients will be instructed in mid-range exercises and will be further assessed for a directional preference. A directional preference is present if movement in a particular direction decreases LBP intensity or causes symptoms to centralize towards the midline. If a subject has a directional preference he or she will be prescribed exercises specifically in that direction along with mid-range exercise. Otherwise the subject will be assigned exercises moving into either flexion or extension based on the clinician's discretion. Subjects will perform their prescribed exercises at treatment sessions and will be instructed to perform the exercises daily on other days.	Phase II - SMT With Mobilizing and Activation Exercises Patients received 2 sessions of SMT during Phase I; and 6 sessions of lumbar multifidus activating exercises and spinal mobilizing exercises during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. Substitution with a side-posture HVLA technique is allowed. Mobilizing Exercises: Mobilizing exercises include repeated movements in spinal flexion and/or extension. Patients will be instructed in mid-range exercises. If a subject has a directional preference he or she will be prescribed exercises specifically in that direction. Otherwise the subject will be assigned exercises moving into flexion or extension based on the clinician's discretion. Subjects will perform their prescribed exercises at treatment sessions and daily on other days. Activation Exercises: Activation exercises facilitate the lumbar multifidus muscle. Exercises begin with isometric multifidus contractions in different positions and co-contraction of multifidus and abdominals. Subjects also perform extensor strengthening exercises. Subjects will perform their prescribed exercises at treatment sessions daily on other days.	Phase II - SMT Extended With Mobilizing Exercises Patients received 2 sessions of SMT during Phase I; and 6 sessions of SMT and spinal mobilizing exercises during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. Substitution with a side-posture HVLA technique is allowed. Mobilizing Exercises: Mobilizing exercises include repeated movements progressing into end-ranges of spinal flexion and/or extension. Patients will be instructed in mid-range exercises and are assessed for a directional preference. If a subject has a directional preference he or she will be prescribed exercises specifically in that direction along with mid-range exercise. Otherwise the subject will be assigned exercises moving into either flexion or extension based on the clinician's discretion. Subjects will perform their prescribed exercises at treatment sessions and will be instructed to perform the exercises daily on other days. SMT extended: This treatment involves 6 additional SMT sessions. Each SMT session is conducted as described previously.	Phase II - SMT Extended With Activation Exercises Patients received 2 sessions of SMT during Phase I; and 6 sessions of SMT and lumbar multifidus activating exercises during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side to manipulate. The side to be manipulated is the more painful. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. Substitution with a side-posture HVLA technique is allowed. Activation Exercises: Activation exercises are designed to facilitate use of the lumbar multifidus muscle. Exercises will begin with isometric multifidus contractions in different positions with clinician feedback and exercises to isometrically co-contract the multifidus and deep abdominal muscles. Subjects will also perform lumbar extensor strengthening exercises shown to produce 20%-50% of multifidus maximum voluntary contraction. Subjects will continue to perform isometric exercises throughout treatment. Subjects will perform their prescribed exercises at treatment sessions and will be instructed to perform the exercises daily on other days. SMT extended: This treatment involves 6 additional SMT sessions. Each SMT session is conducted as described previously.	Phase II - SMT Extended With Activation and Mobilizing Exercises Patients received 2 sessions of SMT during Phase I; and 6 sessions of SMT, multifidus activating and spinal mobilizing exercises during Phase II. SMT: All patients receive 2 SMT sessions in the first week. The subject is supine. The clinician stands opposite the side to be manipulated and side-bends the subject away from the side. The side to be manipulated is the more painful. The clinician rotates the subject, and delivers a high-velocity, low-amplitude (HVLA) thrust to the pelvis in a posterior/inferior direction. Substitution with a side-posture HVLA technique is allowed. Mobilizing Exercises: include repeated movements in spinal flexion and/or extension. Patients will be instructed in mid-range exercises. If a subject has a directional preference he or she will be prescribed exercises specifically in that direction. Otherwise the subject will be assigned exercises moving into flexion or extension based on the clinician's discretion. Subjects will perform their prescribed exercises at treatment sessions and daily on other days. Activation Exercises: Activation exercises facilitate the lumbar multifidus muscle. Exercises begin with isometric multifidus contractions in different positions and co-contraction of multifidus and abdominals. Subjects also perform extensor strengthening exercises. Subjects will perform their prescribed exercises at treatment sessions daily on other days. SMT extended: 6 additional SMT sessions, each conducted as described previously.
Overall Study STARTED	30	29	30	31	30	29	30	32
Overall Study COMPLETED	22	23	26	27	24	26	24	26
Overall Study NOT COMPLETED	8	6	4	4	6	3	6	6

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Phase II - No Further Treatment n=30 Participants Phase II baseline values from the 1-weekassessment for participants who did not receive additional treatment in Phase II	Phase II - Extended SMT Only n=29 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of additional SMT in Phase II	Phase II - Activating Exercise Component Only n=30 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of activating exercises only in Phase II	Phase II - Mobilizing Exercise Component Only n=31 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of mobilizing exercises only in Phase II	Phase II i SMT and Activating Exercise Component n=30 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of activating exercises and SMT in Phase II	Phase II - - SMT With Mobilizing Exercise Component n=29 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of mobilizing exercises and SMT in Phase II	Phase II - Activating Exercise and Mobilizing Exercise Components n=30 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of mobilizing exercises and activating exercises in Phase II	Phase II - SMT With Mobilizing Exercise and Activating Exercise n=32 Participants Phase II baseline values from the 1-weekassessment for participants who received 2 sessions per week of mobilizing exercises and activating exercises and SMT in Phase II	Total n=241 Participants Total of all reporting groups
Age, Continuous Phase II baseline age	42.6 years STANDARD_DEVIATION 11.5 • n=5 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	36.3 years STANDARD_DEVIATION 9.8 • n=7 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	41.1 years STANDARD_DEVIATION 12.6 • n=5 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	38.1 years STANDARD_DEVIATION 10.5 • n=4 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	41.2 years STANDARD_DEVIATION 13.7 • n=21 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	40.4 years STANDARD_DEVIATION 12 • n=8 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	40.5 years STANDARD_DEVIATION 10.5 • n=8 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	38.8 years STANDARD_DEVIATION 12.3 • n=24 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.	39.9 years STANDARD_DEVIATION 11.8 • n=42 Participants • A total of 273 met all eligibility criteria and enrolled in Phase I of the study. Of these 32 (11.7%) withdrew during treatment phase I, leaving 241 participants who completed the 1-week assessment and were randomized to receive additional treatment components in Phase II.
Sex: Female, Male Phase II - Baseline Sex · Female	18 Participants n=5 Participants	20 Participants n=7 Participants	20 Participants n=5 Participants	19 Participants n=4 Participants	18 Participants n=21 Participants	15 Participants n=8 Participants	16 Participants n=8 Participants	18 Participants n=24 Participants	144 Participants n=42 Participants
Sex: Female, Male Phase II - Baseline Sex · Male	12 Participants n=5 Participants	9 Participants n=7 Participants	10 Participants n=5 Participants	12 Participants n=4 Participants	12 Participants n=21 Participants	14 Participants n=8 Participants	14 Participants n=8 Participants	14 Participants n=24 Participants	97 Participants n=42 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants	3 Participants n=7 Participants	4 Participants n=5 Participants	3 Participants n=4 Participants	3 Participants n=21 Participants	6 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	20 Participants n=42 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	28 Participants n=5 Participants	25 Participants n=7 Participants	26 Participants n=5 Participants	28 Participants n=4 Participants	27 Participants n=21 Participants	21 Participants n=8 Participants	30 Participants n=8 Participants	32 Participants n=24 Participants	217 Participants n=42 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	2 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	4 Participants n=42 Participants
Race (NIH/OMB) American Indian or Alaska Native	3 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	1 Participants n=24 Participants	4 Participants n=42 Participants
Race (NIH/OMB) Asian	2 Participants n=5 Participants	3 Participants n=7 Participants	5 Participants n=5 Participants	4 Participants n=4 Participants	2 Participants n=21 Participants	2 Participants n=8 Participants	3 Participants n=8 Participants	4 Participants n=24 Participants	25 Participants n=42 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Race (NIH/OMB) Black or African American	1 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	1 Participants n=21 Participants	1 Participants n=8 Participants	2 Participants n=8 Participants	0 Participants n=24 Participants	7 Participants n=42 Participants
Race (NIH/OMB) White	22 Participants n=5 Participants	19 Participants n=7 Participants	19 Participants n=5 Participants	21 Participants n=4 Participants	24 Participants n=21 Participants	21 Participants n=8 Participants	25 Participants n=8 Participants	25 Participants n=24 Participants	176 Participants n=42 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants	3 Participants n=4 Participants	2 Participants n=21 Participants	2 Participants n=8 Participants	0 Participants n=8 Participants	2 Participants n=24 Participants	13 Participants n=42 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	5 Participants n=7 Participants	3 Participants n=5 Participants	3 Participants n=4 Participants	1 Participants n=21 Participants	3 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	16 Participants n=42 Participants
Chronic LBP	24 Participants n=5 Participants	22 Participants n=7 Participants	23 Participants n=5 Participants	25 Participants n=4 Participants	26 Participants n=21 Participants	20 Participants n=8 Participants	21 Participants n=8 Participants	22 Participants n=24 Participants	183 Participants n=42 Participants
Oswestry	35.7 units on a scale STANDARD_DEVIATION 11.8 • n=5 Participants	36.1 units on a scale STANDARD_DEVIATION 17.7 • n=7 Participants	33.9 units on a scale STANDARD_DEVIATION 10.0 • n=5 Participants	30.6 units on a scale STANDARD_DEVIATION 8.6 • n=4 Participants	36.3 units on a scale STANDARD_DEVIATION 11.5 • n=21 Participants	29.1 units on a scale STANDARD_DEVIATION 9.5 • n=8 Participants	32.7 units on a scale STANDARD_DEVIATION 9.3 • n=8 Participants	38.6 units on a scale STANDARD_DEVIATION 12.0 • n=24 Participants	34.4 units on a scale STANDARD_DEVIATION 11.8 • n=42 Participants
Pain intensity	4.4 units on a scale STANDARD_DEVIATION 1.5 • n=5 Participants	4.9 units on a scale STANDARD_DEVIATION 2.0 • n=7 Participants	4.8 units on a scale STANDARD_DEVIATION 1.5 • n=5 Participants	4.4 units on a scale STANDARD_DEVIATION 1.7 • n=4 Participants	4.5 units on a scale STANDARD_DEVIATION 1.5 • n=21 Participants	4.4 units on a scale STANDARD_DEVIATION 1.7 • n=8 Participants	4.5 units on a scale STANDARD_DEVIATION 1.6 • n=8 Participants	4.9 units on a scale STANDARD_DEVIATION 1.7 • n=24 Participants	4.6 units on a scale STANDARD_DEVIATION 1.7 • n=42 Participants
Multifidus Activation	11.4 percentage increase in thickness STANDARD_DEVIATION 9.5 • n=5 Participants	9.5 percentage increase in thickness STANDARD_DEVIATION 9.4 • n=7 Participants	13.6 percentage increase in thickness STANDARD_DEVIATION 11.4 • n=5 Participants	11.6 percentage increase in thickness STANDARD_DEVIATION 8.5 • n=4 Participants	14.2 percentage increase in thickness STANDARD_DEVIATION 10.9 • n=21 Participants	10.7 percentage increase in thickness STANDARD_DEVIATION 9.1 • n=8 Participants	10.0 percentage increase in thickness STANDARD_DEVIATION 8.9 • n=8 Participants	11.6 percentage increase in thickness STANDARD_DEVIATION 8.2 • n=24 Participants	11.2 percentage increase in thickness STANDARD_DEVIATION 9.3 • n=42 Participants
Spinal Stiffness	6.0 N/mm STANDARD_DEVIATION 1.2 • n=5 Participants	5.8 N/mm STANDARD_DEVIATION 1.4 • n=7 Participants	5.9 N/mm STANDARD_DEVIATION 1.3 • n=5 Participants	6.3 N/mm STANDARD_DEVIATION 1.1 • n=4 Participants	5.7 N/mm STANDARD_DEVIATION 1.2 • n=21 Participants	5.9 N/mm STANDARD_DEVIATION 1.4 • n=8 Participants	5.7 N/mm STANDARD_DEVIATION 1.1 • n=8 Participants	5.9 N/mm STANDARD_DEVIATION 1.0 • n=24 Participants	6.0 N/mm STANDARD_DEVIATION 1.4 • n=42 Participants

PRIMARY outcome

Timeframe: Assessed at Phase II Baseline, 4 weeks, 12 weeks. 4 weeks and 12 weeks reported. Phase II baseline values were constrained to be equal to a common overall mean for analyses.

Population: Results were examined based on the main effects and interactions among the 3 treatment components in the factorial study design (SMT, Mobilizing Exercise, Activating Exercise). Scores were missing for participants in the SMT group (n=21 at 4 weeks and 12 weeks), Mobilizing exercise (n=14 at 4 weeks and n=19 at 12 weeks), and Activating exercise (n=16 at 4 weeks and n=22 at 12 weeks)

Outcome measures

Outcome measures
Measure	SMT Treatment Component n=99 Participants Participants who received extended SMT in weeks 2-4 based on randomized assignment in the factorial study design.	Mobilizing Exercise Component n=108 Participants Participants who received mobilizing exercises in weeks 2-4 based on randomized assignment in the factorial study design.	Activating Exercise Component n=106 Participants Participants who received activating exercises in weeks 2-4 based on randomized assignment in the factorial study design.
Spinal Stiffness Spinal Stiffness measure at 4 weeks	6.20 N/mm Interval 5.98 to 6.41	6.28 N/mm Interval 6.07 to 6.48	6.10 N/mm Interval 5.9 to 6.31
Spinal Stiffness Spinal Stiffness measure at 12 weeks	6.07 N/mm Interval 5.85 to 6.28	6.16 N/mm Interval 5.96 to 6.37	6.06 N/mm Interval 5.85 to 6.27

PRIMARY outcome

Timeframe: Assessed at Phase II Baseline, 4 weeks, 12 weeks. 4 weeks and 12 weeks reported. Phase II baseline values were constrained to be equal to a common overall mean for analyses.

Multifidus activation was measured with brightness-mode ultrasound images using a 60mm, 2-5 MHz curvilinear array. Images are acquired with the multifidus at rest and during submaximal contraction. Three images in each state are acquired and averaged. Muscle activation is calculated as the change in thickness at rest and submaximal contraction and expressed as a percentage change. Greater numbers indicate higher muscle activation.

Outcome measures

Outcome measures
Measure	SMT Treatment Component n=99 Participants Participants who received extended SMT in weeks 2-4 based on randomized assignment in the factorial study design.	Mobilizing Exercise Component n=108 Participants Participants who received mobilizing exercises in weeks 2-4 based on randomized assignment in the factorial study design.	Activating Exercise Component n=106 Participants Participants who received activating exercises in weeks 2-4 based on randomized assignment in the factorial study design.
Multifidus Activation Multifidus Activation 4 weeks	12.10 percentage Interval 10.2 to 14.0	12.42 percentage Interval 10.56 to 14.28	12.0 percentage Interval 10.09 to 13.84
Multifidus Activation Multifidus Activation 12 weeks	12.20 percentage Interval 10.28 to 14.12	12.74 percentage Interval 10.87 to 14.62	12.10 percentage Interval 10.22 to 13.97

SECONDARY outcome

Timeframe: Assessed at Phase II Baseline, 4 weeks, 12 weeks. 4 weeks and 12 weeks reported. Phase II baseline values were constrained to be equal to a common overall mean for analyses.

The Oswestry Disability Index measures back pain-related disability. The scale contains 10 items with a minimum score of zero and maximum score of 100. Higher numbers indicate more disability. There are no subscales.

Outcome measures

Outcome measures
Measure	SMT Treatment Component n=99 Participants Participants who received extended SMT in weeks 2-4 based on randomized assignment in the factorial study design.	Mobilizing Exercise Component n=108 Participants Participants who received mobilizing exercises in weeks 2-4 based on randomized assignment in the factorial study design.	Activating Exercise Component n=106 Participants Participants who received activating exercises in weeks 2-4 based on randomized assignment in the factorial study design.
Oswestry Disability Index Oswestry 4 week outcomes	21.74 units on a scale Interval 19.23 to 24.25	21.64 units on a scale Interval 19.18 to 24.1	21.15 units on a scale Interval 18.7 to 23.61
Oswestry Disability Index Oswestry 12 week outcomes	19.73 units on a scale Interval 17.05 to 22.42	18.97 units on a scale Interval 16.33 to 21.62	18.02 units on a scale Interval 15.38 to 20.66

SECONDARY outcome

Timeframe: Assessed at Phase II Baseline, 4 weeks, 12 weeks. 4 weeks and 12 weeks reported. Phase II baseline values were constrained to be equal to a common overall mean for analyses.

A 0-10 numeric pain rating is used to assess pain intensity. The minimum score is zero, maximum score is 10. Higher numbers indicate greater pain intensity. There are no subscales.