Spinal Muscular Atrophy (SMA)NCT07822711
Effects of Different Stiffness Settings During Robotic Isokinetic Training in Children With SMA
A study testing Portable Isokinetic Knee Training Robot With an Individually Optimized Compliant Setting and Portable Isokinetic Knee Training Robot With a Rigid Setting in people with Spinal Muscular Atrophy (SMA), run by Peking University Third Hospital at 1 site in China.
Trial summary
This randomized, within-participant, contralateral-limb-controlled clinical trial will compare individually optimized compliant and rigid stiffness settings of a portable isokinetic knee training robot in children with spinal muscular atrophy. At least 13 children aged 6 to 12 years will be enrolled. Read more about this study
- Who is it for?
- Ages 6 to 12 years
- Conditions the study is for
- Spinal Muscular Atrophy (SMA)
- What is being tested?
- Portable Isokinetic Knee Training Robot With an Individually Optimized Compliant Setting and Portable Isokinetic Knee Training Robot With a Rigid Setting
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteChina
- Study dates
- 22 Oct 2026to 30 Jan 2027
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 12 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Age 6 to 12 years.
- Diagnosis of spinal muscular atrophy.
- Able to maintain an independent seated position.
- If receiving disease-modifying treatment, including nusinersen or risdiplam, the participant must have received a stable dose for at least 6 months before enrollment and must not change the treatment regimen during the study.
Who cannot join
- Any other major disease or medical condition that, in the investigator's judgment, would interfere with safe participation or interpretation of the study results.
- The legal guardian declines to provide written informed consent, or the participant is unable to complete the study procedures.
- Unable to undergo magnetic resonance imaging or electromyography and nerve conduction testing.
- Blood pressure above the 95th percentile for age, sex, and height, as assessed by a clinician.
- Lacks the cognitive capacity to understand or comply with the requirements of study participation.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Peking University Third Hospital
Beijing, 100191
Jiaxin Ren, +8613111050197, tildaren@163.com
About this study
Official title: Effects of Different Stiffness Settings on Isokinetic Quadriceps Training in Children With Spinal Muscular Atrophy: A Randomized Within-Participant, Contralateral-Limb-Controlled Trial
This randomized, within-participant, contralateral-limb-controlled clinical trial will compare individually optimized compliant and rigid stiffness settings of a portable isokinetic knee training robot in children with spinal muscular atrophy. At least 13 children aged 6 to 12 years will be enrolled. For each participant, one leg will be randomly assigned to the compliant setting and the contralateral leg to the rigid setting using sequentially numbered, opaque, sealed envelopes. Both legs will receive the same training volume, number of repetitions, and angular velocity for up to 8 weeks. The primary outcome is the between-setting difference in the change from baseline in peak isokinetic knee-extension torque. Secondary outcomes include knee-extension range of motion, quadriceps cross-sectional area on magnetic resonance imaging, femoral nerve conduction measures, and sit-to-stand performance. Knee pain, suprapatellar skin temperature, fatigue, and other adverse events will be monitored throughout the study.
Read the detailed description
Spinal muscular atrophy is characterized by progressive muscle weakness and impaired motor function. Quadriceps weakness limits knee extension, transfers, standing, and other activities of daily living. A portable isokinetic knee training robot has previously been shown to provide safe, quantifiable resistance training in children with spinal muscular atrophy. The present study will investigate whether the stiffness of the human-robot interaction affects rehabilitation outcomes.
Participants will be randomized to one of two laterality schemes: (A) compliant setting for the left leg and rigid setting for the right leg, or (B) rigid setting for the left leg and compliant setting for the right leg. An independent statistician will generate the random sequence, which will be concealed in sequentially numbered, opaque, sealed envelopes. The study is open label.
Before training, participants will undergo bilateral quadriceps magnetic resonance imaging, femoral nerve conduction testing, biomechanical assessment, and determination of the individually optimized compliant stiffness. Under the compliant setting, stiffness will be selected within the predefined safe range as the level that produces the highest mean peak knee-extension torque across five repetitions while the movement remains painless, without obvious fatigue, and with a stable trajectory.
Training will continue for up to 8 weeks, with no more than five sessions per week. During each session, the robot will be worn on one leg at a time while the contralateral leg is stabilized. Participants will perform seated knee extension and flexion at a target angular velocity of 45 degrees per second, adjusted when clinically necessary. The initial knee angle will be 90 degrees, and movement will occur within each participant's maximum voluntary pain-free range of motion. A standard set will consist of 10 continuous extension-flexion repetitions, with at least six sets per leg and approximately 1 minute of rest between sets. The number of repetitions, sets, and rest duration may be adjusted according to participant tolerance, but the training dose will be matched between the two legs. Total session duration will be approximately 35 minutes.
The robot software will record training data, including knee-extension peak torque and joint angle. After the intervention, bilateral quadriceps magnetic resonance imaging, femoral nerve conduction testing, and biomechanical assessments will be repeated. Participants will be evaluated in person before and after the intervention and contacted weekly by telephone during training to assess knee pain, discomfort, fatigue, and subjective changes in strength.
- Conditions
- Spinal Muscular Atrophy (SMA)
- Being tested
- Portable Isokinetic Knee Training Robot With an Individually Optimized Compliant Setting, Portable Isokinetic Knee Training Robot With a Rigid Setting
- Medical subject headings
- Muscular Atrophy, Spinal
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Portable Isokinetic Knee Training Robot With an Individually Optimized Compliant SettingDevice
The compliant setting will be individualized within the device's predefined safe stiffness range. At each candidate stiffness, the participant will perform five knee-extension repetitions. The stiffness producing the highest mean peak knee-extension torque while the movement remains painless, without obvious fatigue, and with a stable trajectory will be selected. The assigned limb will then train at this setting for up to 8 weeks, no more than five sessions per week. Each session will use a target angular velocity of 45 degrees per second, an individualized maximum voluntary pain-free range of motion, at least six sets of 10 extension-flexion repetitions per leg, and approximately 1 minute of rest between sets. Training volume will be matched to the contralateral limb.
Portable Isokinetic Knee Training Robot With a Rigid SettingDevice
The assigned limb will train with the device's predefined rigid stiffness setting for up to 8 weeks, no more than five sessions per week. Each session will use a target angular velocity of 45 degrees per second, an individualized maximum voluntary pain-free range of motion, at least six sets of 10 extension-flexion repetitions per leg, and approximately 1 minute of rest between sets. Training volume will be matched to the contralateral limb.
| Study group | Role | What they receive |
|---|---|---|
| Scheme A: Left Compliant, Right Rigid | Experimental | Participants assigned to scheme A will receive isokinetic knee training with the individually optimized compliant stiffness setting on the left leg and the rigid stiffness setting on the right leg. Training dose, angular velocity, number of repetitions, number of sets, and rest periods will be matched between the two legs. Receives: Device: Portable Isokinetic Knee Training Robot With an Individually Optimized Compliant Setting; Device: Portable Isokinetic Knee Training Robot With a Rigid Setting |
| Scheme B: Left Rigid, Right Compliant | Experimental | Participants assigned to scheme B will receive isokinetic knee training with the rigid stiffness setting on the left leg and the individually optimized compliant stiffness setting on the right leg. Training dose, angular velocity, number of repetitions, number of sets, and rest periods will be matched between the two legs. Receives: Device: Portable Isokinetic Knee Training Robot With an Individually Optimized Compliant Setting; Device: Portable Isokinetic Knee Training Robot With a Rigid Setting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Between-setting difference in the change from baseline in peak knee-extension torque
Peak isokinetic knee-extension torque will be measured separately for each limb using the portable isokinetic knee training robot and reported in newton-meters. For each participant, the change from baseline will be calculated for the compliant-setting limb and the rigid-setting limb. The primary outcome is the within-participant difference between these two changes: (post-intervention minus baseline change for the compliant setting) minus (post-intervention minus baseline change for the rigid setting).
Measured: Baseline and immediately after the intervention period, up to 8 weeks
Secondary outcomes (4)
Between-setting difference in the change from baseline in active knee-extension range of motion
Active knee-extension range of motion will be measured separately for each limb by the robot and reported in degrees. The outcome is the within-participant difference between the compliant-setting and rigid-setting limbs in change from baseline.
Measured: Baseline and immediately after the intervention period, up to 8 weeks
Between-setting difference in the change from baseline in quadriceps cross-sectional area
Quadriceps cross-sectional area will be quantified separately for each thigh using magnetic resonance imaging and reported in square centimeters. The outcome is the within-participant difference between the compliant-setting and rigid-setting limbs in change from baseline.
Measured: Baseline and immediately after the intervention period, up to 8 weeks
Between-setting difference in the change from baseline in femoral nerve compound muscle action potential amplitude
Femoral nerve conduction testing will be performed separately for each limb. Compound muscle action potential amplitude will be reported in millivolts. The outcome is the within-participant difference between the compliant-setting and rigid-setting limbs in change from baseline.
Measured: Baseline and immediately after the intervention period, up to 8 weeks
Change from baseline in the minimum initial knee angle for successful sit-to-stand performance
The minimum initial knee flexion angle from which the participant can successfully complete an unassisted sit-to-stand task will be measured in degrees. The post-intervention value will be compared with baseline at the participant level.
Measured: Baseline and immediately after the intervention period, up to 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Sep 2026
- Study start22 Oct 2026 (estimated)
- Primary completion15 Jan 2027 (estimated)
- Study completion30 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Spinal Muscular Atrophy (SMA)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized within-participant split-body design. Each participant receives both stiffness settings concurrently, one on each lower limb. Randomization determines only the left-right assignment: scheme A assigns the compliant setting to the left leg and the rigid setting to the right leg, whereas scheme B assigns the rigid setting to the left leg and the compliant setting to the right leg. Outcomes for the two settings are compared within each participant.
- Masking
- None (open label)
- Enrolment
- 13 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Peking University Third Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yuan Fuzhen, Peking University Third Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07822711
- Sponsor's protocol ID
- 2026-536-02
- Status last verified
- Oct 2026
- First submitted
- 13 Sep 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because the study involves children with a rare disease and a small sample size, which may increase the risk of participant re-identification.