An interventional study of Visual Surface EMG Biofeedback and Standard Rehabilitation Without Visual Biofeedback in Arthrogenic Muscle Inhibition, Knee Injuries and Postoperative Rehabilitation, sponsored by Hopitaux de Saint-Maurice. Active, not recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-01.
Sponsored by Hopitaux de Saint-Maurice · Not applicable, Interventional, and Treatment
Among 13 studies in Knee Injuries with a site in France — 4 open to participants now, 5 under way, none of them phase 3. Knee Injuries · France.
Among the 13 studies in Knee Injuries with a site in France, this one is one of 3 that started in 2026, is one of 5 with no phase, and was the 13th registered.
267 studies on the registry are indexed under Knee Injuries; 59 are open to participants now.
Browse Knee Injuries studies →4 of the 13 studies in Knee Injuries with a site in France are open now. Recruiting first, the newest first:
University Hospital, Montpellier · Sites in France
Ages 18–45 · Men only · Healthy volunteers
University Hospital, Strasbourg, France · Sites in France
Ages 1–17
Versailles Hospital · Sites in France
Ages 18+
Haute Ecole ARC Sante · Sites in France, Switzerland
Ages 18–35
A study can be open while its sites in France have not opened yet or have stopped. Only those recruiting at a site in France →
Of the 42 Knee Injuries studies recruiting now, 12 (29%) set no upper age limit and 27 (64%) stop at 75 or younger; 12 take children under 18; 9 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
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13 studies; the count open now beside each. This study's row is marked.
First in 2006; this study’s year is marked. 3 started in 2026.
This study's planned enrollment of 5 is below the median of 49 across 178 interventional studies indexed under Knee Injuries.
Median enrollment 70 across the 6 interventional studies, 150 across the 7 observational. Of the 7 that completed or were terminated, 0 (0%) have results posted.
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None of the 13 has an industry lead sponsor. The 10 most frequent:
Hopitaux de Saint-Maurice is the lead sponsor of 16 studies on the registry; 6 are open to participants now.
Hopitaux de Saint-Maurice has 1 study filed under Knee Injuries — fewer than ten, so there is no comparison to draw.
None of the studies under way reaches primary completion within a year.
Among the 13 studies in Knee Injuries with a site in France, from their registry updates:
Nothing recorded among them since 2026-09-25.
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Arthrogenic muscle inhibition (AMI) is a common neurological impairment following knee surgery that limits voluntary quadriceps activation and delays functional recovery. Persistent AMI may contribute to muscle weakness, altered gait, and poorer rehabilitation outcomes. Although several rehabilitation strategies have been proposed, no complementary intervention has consistently demonstrated strong evidence for improving AMI.
This prospective single-case experimental study aims to evaluate whether visual biofeedback based on surface electromyography (sEMG) improves quadriceps motor performance during standard rehabilitation. Each participant will complete eight standardized rehabilitation sessions, including four sessions with visual sEMG biofeedback and four sessions without visual feedback. The order of the two conditions will be randomized, allowing each participant to serve as his or her own control.
The primary objective is to determine whether visual sEMG biofeedback improves the accuracy of quadriceps contraction, assessed by the percentage deviation from a predefined target. Secondary objectives include evaluation of motor engagement, motor control, muscle activation, perceived exertion, and pain.
Between three and five adult patients presenting AMI after knee surgery will be included. Because recovery patterns are highly individualized, a Single-Case Experimental Design (SCED) with repeated within-subject measurements has been selected to characterize individual treatment responses while minimizing inter-individual variability
Arthrogenic muscle inhibition (AMI) is a reflexive neurological response commonly observed after knee surgery. It results from altered afferent input originating from the injured joint, leading to reduced voluntary activation of the quadriceps muscle. AMI contributes to muscle weakness, impaired knee extension, gait abnormalities, and delayed functional recovery. Persistent inhibition may negatively affect long-term rehabilitation outcomes.
Surface electromyography (sEMG) biofeedback provides real-time visual information about muscle activation, enabling patients to voluntarily adjust their contractions during rehabilitation exercises. Previous studies suggest that EMG biofeedback may improve neuromuscular activation and motor learning, although evidence remains limited.
The BIOQUAD study is a prospective, within-subject Single-Case Experimental Design (SCED) conducted in adult patients undergoing rehabilitation after knee surgery who present AMI. This design was selected because of the high inter-individual variability in neuromuscular recovery and the exploratory nature of the study. Each participant acts as his or her own control through repeated measurements under two experimental conditions.
Each participant will complete eight standardized rehabilitation sessions over approximately three weeks:
At the beginning of each session, maximal quadriceps activation (EMGmax) will be calibrated using three maximal voluntary contractions. Participants will then perform six standardized contractions targeting 80% of EMGmax, each maintained for five seconds and separated by fifteen seconds of rest.
The primary endpoint is contraction accuracy, defined as the percentage deviation from the target muscle activation level. Secondary outcomes include:
time spent within the target activation zone (±5%);
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Participants perform standardized rehabilitation exercises with real-time visual surface electromyography biofeedback.
Behavioral: Visual Surface EMG Biofeedback
Participants perform the same standardized rehabilitation exercises without visual biofeedback. Surface EMG signals are recorded but not displayed to the participant.
Behavioral: Standard Rehabilitation Without Visual Biofeedback
Participants perform standardized rehabilitation exercises while receiving real-time visual feedback of quadriceps muscle activity using surface electromyography (sEMG)
Participants perform the same standardized rehabilitation exercises without visual biofeedback. Surface electromyography signals are recorded but are not displayed to the participant.
Percentage Deviation From the Target Quadriceps Activation Level
The percentage deviation between the quadriceps muscle activation achieved by the participant and the predefined target activation level of 80% of the maximal surface electromyography activity (EMGmax). The measure will be calculated for each contraction performed during sessions with visual sEMG biofeedback and sessions without visual biofeedback. The percentage deviation between the participant's quadriceps muscle activation and the predefined target activation level (80% of EMGmax). Lower values indicate greater contraction accuracy.
Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
Time Spent Within the Target Quadriceps Activation Zone
Duration, expressed in seconds, during which quadriceps muscle activation remains within ±5% of the predefined target level of 80% of EMGmax during each contraction. A longer time within the target zone indicates better motor control.
Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
Quadriceps Motor Latency
Time, expressed in seconds, between the instruction to initiate the contraction and the onset of the quadriceps muscle activation recorded by surface electromyography. A shorter latency indicates a faster motor response.
Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
Maximal Quadriceps Surface Electromyography Activity
Maximum quadriceps muscle activation recorded by surface electromyography during the calibration procedure performed at the beginning of each session. EMGmax is determined from three maximal voluntary contractions lasting 5 seconds each
Time frame: At the beginning of each of the 8 rehabilitation sessions, over approximately 3 weeks
Perceived Exertion Assessed Using the Borg Scale
Participant-reported perceived exertion assessed at the end of each rehabilitation session using the Borg CR10 Scale (range: 0-10). Higher scores indicate greater perceived exertion.
Time frame: At the end of each of the 8 rehabilitation sessions, over approximately 3 weeks
Pain Intensity Assessed Using a Numeric Rating Scale
Participant-reported pain intensity assessed at the end of each rehabilitation session using an 11-point Numeric Rating Scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain.
Time frame: At the end of each of the 8 rehabilitation sessions, over approximately 3 weeks
Plan to share: No — No plan to make individual participant data available to other researchers.
No publications or documents are linked to this record.
Started Jul 2026 (actual). Primary completion is estimated for Sep 2026, 2 months after the start.
Of 94 non-industry interventional studies with no phase under Knee Injuries, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 51. This study's planned 2 months is below that.
Counting every sponsor, half of 99 studies reached it within 20 months; a quarter within 8 and three quarters within 51.
Start moved once since we started tracking on Sep 25, 2026: Aug 2026 → Jul 2026, on Oct 1, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Hopitaux de Saint-Maurice