Trial Outcomes & Findings for Combined Application of Electrical Stimulation and Volitional Contractions for Muscle Strengthening and Knee Pain Inhibition (Seated Study) (NCT NCT02802878)

NCT ID: NCT02802878

Last Updated: 2018-05-18

Results Overview

Participants will be familiarized with strength testing equipment and counseled on proper lifting technique. They will undergo testing to determine their peak isokinetic knee extensor torque at 60°/sec, using an isokinetic dynamometer. These testing procedures will then be repeated for the other side.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 42 participants
• Primary outcome timeframe: Baseline and 12-week follow-up
• Results posted on: 2018-05-18

Participant Flow

Participant milestones

Measure	Hybrid Training The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise 40% max isokinetic training in same repetitions/sets as experimental group. Isokinetic Training with Computer Sports Medicine Inc. (CSMi) HUMAC NORM: Low intensity exercises completed using CSMi HUMAC NORM in isokinetic mode at approximately 40%1 RM.
Overall Study STARTED	21	21
Overall Study COMPLETED	17	18
Overall Study NOT COMPLETED	4	3

Reasons for withdrawal

Measure	Hybrid Training The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise 40% max isokinetic training in same repetitions/sets as experimental group. Isokinetic Training with Computer Sports Medicine Inc. (CSMi) HUMAC NORM: Low intensity exercises completed using CSMi HUMAC NORM in isokinetic mode at approximately 40%1 RM.
Overall Study Withdrawal by Subject	3	3
Overall Study Protocol Violation	1	0

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Measure	Hybrid Training n=21 Participants The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise n=21 Participants 40% max isokinetic training in same repetitions/sets as experimental group. Isokinetic Training with Computer Sports Medicine Inc. (CSMi) HUMAC NORM: Low intensity exercises completed using CSMi HUMAC NORM in isokinetic mode at approximately 40%1 RM.	Total n=42 Participants Total of all reporting groups
Age, Continuous	67.62 years STANDARD_DEVIATION 8.38 • n=21 Participants	65.14 years STANDARD_DEVIATION 9.51 • n=21 Participants	66.38 years STANDARD_DEVIATION 8.94 • n=42 Participants
Sex: Female, Male Female	21 Participants n=21 Participants	21 Participants n=21 Participants	42 Participants n=42 Participants
Sex: Female, Male Male	0 Participants n=21 Participants	0 Participants n=21 Participants	0 Participants n=42 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Height	165.38 centimeters (cm) STANDARD_DEVIATION 4.96 • n=21 Participants	163.38 centimeters (cm) STANDARD_DEVIATION 8.53 • n=21 Participants	164.4 centimeters (cm) STANDARD_DEVIATION 6.96 • n=42 Participants
Body Mass	74.49 kilograms (kg) STANDARD_DEVIATION 15.66 • n=21 Participants	76.14 kilograms (kg) STANDARD_DEVIATION 15.56 • n=21 Participants	75.31 kilograms (kg) STANDARD_DEVIATION 15.44 • n=42 Participants
Body Mass Index (BMI)	27.29 kg/m^2 STANDARD_DEVIATION 5.99 • n=21 Participants	28.45 kg/m^2 STANDARD_DEVIATION 5.33 • n=21 Participants	27.87 kg/m^2 STANDARD_DEVIATION 5.64 • n=42 Participants
20-Meter Walk Time	13.12 seconds STANDARD_DEVIATION 4.38 • n=21 Participants	13.78 seconds STANDARD_DEVIATION 3.22 • n=21 Participants	13.49 seconds STANDARD_DEVIATION 3.81 • n=42 Participants
5-Chair Stand Time	17.13 seconds STANDARD_DEVIATION 11.75 • n=21 Participants	15.36 seconds STANDARD_DEVIATION 4.35 • n=21 Participants	16.25 seconds STANDARD_DEVIATION 8.79 • n=42 Participants
Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain	60.85 units on a scale STANDARD_DEVIATION 15.47 • n=21 Participants	54.86 units on a scale STANDARD_DEVIATION 14.55 • n=21 Participants	57.9 units on a scale STANDARD_DEVIATION 15.07 • n=42 Participants
Extensor Torque	69.40 Newton-meters STANDARD_DEVIATION 3.67 • n=21 Participants	67.60 Newton-meters STANDARD_DEVIATION 3.57 • n=21 Participants	68.50 Newton-meters STANDARD_DEVIATION 3.62 • n=42 Participants
Flexor Torque	31.32 Newton-meters STANDARD_DEVIATION 1.82 • n=21 Participants	28.36 Newton-meters STANDARD_DEVIATION 1.77 • n=21 Participants	29.84 Newton-meters STANDARD_DEVIATION 1.80 • n=42 Participants

PRIMARY outcome

Timeframe: Baseline and 12-week follow-up

Population: 4 participants in the hybrid training group discontinued the intervention due to unrelated pain, knee injections, car issues, and unrelated hospitalization. 3 participants in the low intensity exercise group discontinued the intervention due to unrelated pain, fatigue and the inability to gain strength due to radiation overdose (unrelated).

Participants will be familiarized with strength testing equipment and counseled on proper lifting technique. They will undergo testing to determine their peak isokinetic knee extensor torque at 60°/sec, using an isokinetic dynamometer. These testing procedures will then be repeated for the other side.

Outcome measures

Measure	Hybrid Training n=17 Participants The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise n=18 Participants Isokinetic Training with isokinetic dynamometer. Low intensity exercises completed in isokinetic mode at approximately 40%1 RM in same repetitions/sets as experimental group.
Change in Maximal Isokinetic Knee Extensor Torque by Body Mass Assessed by Isokinetic Dynamometer.	0.06 Newton-meters/kilogram Standard Error 0.04	0.03 Newton-meters/kilogram Standard Error 0.04

SECONDARY outcome

Timeframe: Baseline and 12-week follow-up

Population: 4 participants in the hybrid training group discontinued the intervention due to unrelated pain, knee injections, car issues, and unrelated hospitalization. 3 participants in the low intensity exercise group discontinued the intervention due to unrelated pain, fatigue and the inability to gain strength due to radiation overdose (unrelated).

Participants will be familiarized with strength testing equipment and counseled on proper lifting technique. They will undergo testing to determine their peak isokinetic knee flexor torque, using an isokinetic dynamometer.

Outcome measures

Measure	Hybrid Training n=17 Participants The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise n=18 Participants Isokinetic Training with isokinetic dynamometer. Low intensity exercises completed in isokinetic mode at approximately 40%1 RM in same repetitions/sets as experimental group.
Change in Maximal Isokinetic Knee Flexor Torque by Body Mass Assessed by Isokinetic Dynamometer.	0.05 Newton-meters/kilogram Standard Error 0.02	0.06 Newton-meters/kilogram Standard Error 0.02

SECONDARY outcome

Timeframe: Baseline and 12-week follow-up

Population: 4 participants in the hybrid training group discontinued the intervention due to unrelated pain, knee injections, car issues, and unrelated hospitalization. 3 participants in the low intensity exercise group discontinued the intervention due to unrelated pain, fatigue and the inability to gain strength due to radiation overdose (unrelated).

The Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain subscale was used at baseline and follow-up to assess participant outcomes. The pain subscale is made up of 9 questions and was scored from zero to 100, with zero corresponding to extreme knee problems and 100 corresponding to no knee problems.

Outcome measures

Measure	Hybrid Training n=17 Participants The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise n=18 Participants Isokinetic Training with isokinetic dynamometer. Low intensity exercises completed in isokinetic mode at approximately 40%1 RM in same repetitions/sets as experimental group.
Change in Knee Pain Assessed by a Knee Injury and Osteoarthritis Outcome Score	11.9 units on a scale Standard Deviation 11.5	14.1 units on a scale Standard Deviation 15.4

SECONDARY outcome

Timeframe: Baseline and 12-week follow-up

Population: 4 participants in the hybrid training group discontinued the intervention due to unrelated pain, knee injections, car issues, and unrelated hospitalization. 3 participants in the low intensity exercise group discontinued the intervention due to unrelated pain, fatigue and the inability to gain strength due to radiation overdose (unrelated).

A timed 20-meter walk was completed as a measure of lower limb physical performance. Participants were instructed to walk along a 20-meters straight, uninterrupted course as quickly as they could. Timing started when the participant initiated foot movement and stopped when both feet crossed the 20-meter mark. Times for two trials were recorded and the averaged.

Outcome measures

Measure	Hybrid Training n=17 Participants The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise n=18 Participants Isokinetic Training with isokinetic dynamometer. Low intensity exercises completed in isokinetic mode at approximately 40%1 RM in same repetitions/sets as experimental group.
Change in 20-meter Walk Time	-1.60 seconds Standard Deviation 2.04	-0.95 seconds Standard Deviation 1.21

SECONDARY outcome

Timeframe: Baseline and 12-week follow-up

Population: 4 participants in the hybrid training group discontinued the intervention due to unrelated pain, knee injections, car issues, and unrelated hospitalization. 3 participants in the low intensity exercise group discontinued the intervention due to unrelated pain, fatigue and the inability to gain strength due to radiation overdose (unrelated).

The chair stand test is a validated measure of physical performance in adults with knee osteoarthritis. Participants were instructed to stand from a chair (seat height 44.45 cm) 5 times as quickly as they could without using their arms. Two trials were timed and averaged.

Outcome measures

Measure	Hybrid Training n=17 Participants The hybrid training system combines the applications of neuromuscular electrical stimulation (NMES) with voluntary contractions (NMES-VC). Training will be performed in a seated position with feet not touching the ground, and will involve each knee flexing and extending alternately. The joint range of motion will be restricted to a 90º arc from approximately 10º to 100º of flexion. Each session will consist of 5 sets of 10 repetitions, 3-second knee flexion and extension contractions on each leg. Sets will be separated by 30-sec rest intervals. Electrodes will be placed on the anterior thigh over the motor points of the bilateral vastus medialis and lateralis, and over the medial and lateral hamstrings on the posterior thigh. Electrical stimulation intensity will be set to approximately 40% of 1 repetition maximum (RM). A joint motion sensor will trigger stimulation of the antagonist once it senses the initiation of volitional contraction of the agonist muscle group.	Low Intensity Exercise n=18 Participants Isokinetic Training with isokinetic dynamometer. Low intensity exercises completed in isokinetic mode at approximately 40%1 RM in same repetitions/sets as experimental group.
Change in 5-chair Stand Time	-4.81 seconds Standard Deviation 9.99	-1.86 seconds Standard Deviation 4.72

Adverse Events

Hybrid Training

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Low Intensity Exercise

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Neil Segal

University of Kansas Medical Center

Phone: 913-945-8985

Email: segal-research@kumc.edu

Results disclosure agreements

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