Arthrogenic Muscle InhibitionBIOQUADNCT07736625
Effect of Surface EMG Biofeedback on Quadriceps Inhibition Release During Postoperative Knee Rehabilitation
A study testing Visual Surface EMG Biofeedback and Standard Rehabilitation Without Visual Biofeedback in people with Arthrogenic Muscle Inhibition and Knee Injuries, run by Hopitaux de Saint-Maurice at 1 site in France.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Arthrogenic Muscle Inhibition, Knee Injuries, Postoperative Rehabilitation
- What is being tested?
- Visual Surface EMG Biofeedback and Standard Rehabilitation Without Visual Biofeedback
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 5 participants
- Where
- 1 siteFrance
- Study dates
- 20 Jul 2026to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- AMI following knee surgery, as classified by the Santi classification system
- Aged 18 or older
- Enrolled in or covered by a social security program
- Able to understand instructions and participate in standardized rehabilitation sessions
Who cannot join
- Acute pain.
- Neurological condition.
- Skin lesion at the electrode site.
- Allergy to the electrode.
- Under legal protective measures such as guardianship or court-ordered protection
Trial locations and contacts
1 site in 1 country.
France1 site
Hôpitaux Paris Est Val-de-Marne - Service de rééducation orthopédique et traumatologie
Saint-Maurice, 94410
About this study
Official title: Effet du Biofeedback Par EMG de Surface Sur la levée d'Inhibition du Quadriceps en rééducation Post-opératoire du Genou
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.
Read more
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
Read the detailed description
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:
- Four sessions with visual sEMG biofeedback.
- Four sessions without visual feedback while EMG signals are still recorded.
- The order of conditions will be randomized using a predefined balanced sequence to reduce learning and order effects.
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%);
- motor latency;
- maximal EMG activity (EMGmax);
- motor engagement score;
- perceived exertion (Borg scale);
- pain intensity (Numeric Rating Scale). Data will be analyzed using SCED methodology with visual and descriptive analyses focusing on level, trend, variability, and overlap between experimental conditions. Results will primarily be interpreted at the individual participant level before descriptive synthesis across participants.
- Being tested
- Visual Surface EMG Biofeedback, Standard Rehabilitation Without Visual Biofeedback
- Keywords
- Surface Electromyography, Electromyography, EMG Biofeedback, Biofeedback, Quadriceps Muscle, Quadriceps Activation, Arthrogenic Muscle Inhibition, Knee Rehabilitation, Knee Surgery, Motor Control, Neuromuscular Rehabilitation, Single-Case Experimental Design, SCED
- Medical subject headings
- Knee Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Visual Surface EMG BiofeedbackBehavioural
Participants perform standardized rehabilitation exercises while receiving real-time visual feedback of quadriceps muscle activity using surface electromyography (sEMG)
Standard Rehabilitation Without Visual BiofeedbackBehavioural
Participants perform the same standardized rehabilitation exercises without visual biofeedback. Surface electromyography signals are recorded but are not displayed to the participant.
| Study group | Role | What they receive |
|---|---|---|
| Visual sEMG Biofeedback | Experimental | Participants perform standardized rehabilitation exercises with real-time visual surface electromyography biofeedback. Receives: Behavioral: Visual Surface EMG Biofeedback |
| No Visual Biofeedback | Active comparator | Participants perform the same standardized rehabilitation exercises without visual biofeedback. Surface EMG signals are recorded but not displayed to the participant. Receives: Behavioral: Standard Rehabilitation Without Visual Biofeedback |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: During each of the 8 rehabilitation sessions, over approximately 3 weeks
Secondary outcomes (5)
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.
Measured: 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.
Measured: 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
Measured: 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.
Measured: 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.
Measured: At the end of each of the 8 rehabilitation sessions, over approximately 3 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jul 2026
- Study start20 Jul 2026
- Primary completion30 Sep 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Arthrogenic Muscle InhibitionStudies 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
- Crossover
- Model description
- Each participant will complete both study conditions: four rehabilitation sessions with visual surface EMG biofeedback and four sessions without visual biofeedback. The order of the conditions will be randomized using a predefined balanced sequence. Each participant serves as his or her own control, allowing within-subject comparison of motor performance outcomes.
- Masking
- None (open label)
- Enrolment
- 5 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hopitaux de Saint-Maurice
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Sylvain SB BELOT, MD, Principal investigator, Hôpitaux Paris Est Val-de-Marne (HPEVM)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07736625
- Sponsor's protocol ID
- BIOQUAD
- Acronym
- BIOQUAD
- Status last verified
- Sep 2026
- First submitted
- 24 Jul 2026
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No plan to make individual participant data available to other researchers.
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effet du Biofeedback Par EMG de Surface Sur la levée d'Inhibition du Quadriceps en rééducation Post-opératoire du Genou
- ClinicalTrials.gov ID
- NCT07736625
- Acronym / sponsor ID
- BIOQUAD / BIOQUAD
- Keywords
- Surface Electromyography, Electromyography, EMG Biofeedback, Biofeedback, Quadriceps Muscle, Quadriceps Activation, Arthrogenic Muscle Inhibition, Knee Rehabilitation
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 5 participants (estimated)
- Lead sponsor
- Hopitaux de Saint-MauriceUniversity, hospital or other
- Study start
- 20 Jul 2026 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 30 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Detailed description
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:
- Four sessions with visual sEMG biofeedback.
- Four sessions without visual feedback while EMG signals are still recorded.
- The order of conditions will be randomized using a predefined balanced sequence to reduce learning and order effects.
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%);
- motor latency;
- maximal EMG activity (EMGmax);
- motor engagement score;
- perceived exertion (Borg scale);
- pain intensity (Numeric Rating Scale). Data will be analyzed using SCED methodology with visual and descriptive analyses focusing on level, trend, variability, and overlap between experimental conditions. Results will primarily be interpreted at the individual participant level before descriptive synthesis across participants.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Each participant will complete both study conditions: four rehabilitation sessions with visual surface EMG biofeedback and four sessions without visual biofeedback. The order of the conditions will be randomized using a predefined balanced sequence. Each participant serves as his or her own control, allowing within-subject comparison of motor performance outcomes.
| Arm | Type | Receives |
|---|---|---|
| Visual sEMG Biofeedback | Experimental | Behavioral: Visual Surface EMG BiofeedbackParticipants perform standardized rehabilitation exercises with real-time visual surface electromyography biofeedback. |
| No Visual Biofeedback | Active comparator | Behavioral: Standard Rehabilitation Without Visual BiofeedbackParticipants perform the same standardized rehabilitation exercises without visual biofeedback. Surface EMG signals are recorded but not displayed to the participant. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- AMI following knee surgery, as classified by the Santi classification system
- Aged 18 or older
- Enrolled in or covered by a social security program
- Able to understand instructions and participate in standardized rehabilitation sessions
Key exclusion criteria (5 listed)
- Acute pain.
- Neurological condition.
- Skin lesion at the electrode site.
- Allergy to the electrode.
- Under legal protective measures such as guardianship or court-ordered protection
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Visual Surface EMG BiofeedbackParticipants perform standardized rehabilitation exercises while receiving real-time visual feedback of quadriceps muscle activity using surface electromyography (sEMG) | Behavioural | Visual sEMG Biofeedback |
| Standard Rehabilitation Without Visual BiofeedbackParticipants perform the same standardized rehabilitation exercises without visual biofeedback. Surface electromyography signals are recorded but are not displayed to the participant. | Behavioural | No Visual Biofeedback |
Primary outcome
Percentage Deviation From the Target Quadriceps Activation Level
Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
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.
5 secondary outcomes
Time Spent Within the Target Quadriceps Activation Zone
Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
Quadriceps Motor Latency
Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
Maximal Quadriceps Surface Electromyography Activity
Time frame: At the beginning of each of the 8 rehabilitation sessions, over approximately 3 weeks
Perceived Exertion Assessed Using the Borg Scale
Time frame: At the end of each of the 8 rehabilitation sessions, over approximately 3 weeks
Pain Intensity Assessed Using a Numeric Rating Scale
Time frame: At the end of each of the 8 rehabilitation sessions, over approximately 3 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2026.
- Individual participant dataSharing planned: No. No plan to make individual participant data available to other researchers.
Related trials for Arthrogenic Muscle Inhibition
Recruiting
Blood Flow Restriction Training in Knee Arthropathy
Knee Arthroscopic Surgery, Arthrogenic Muscle Inhibition
Not yet recruiting
Effects of Anodal Transcranial Direct Current Stimulation on Muscle Inhibition After ACL Reconstruction
ACL Reconstruction
RecruitingPhase 2
Brain-Computer Interface Visualization Training to Optimize Muscle Activation Following Orthopaedic Surgery
Anterior Cruciate Ligament Reconstruction, Total Hip Arthroplasty (THA)
Recruiting
Comparison of Arthrogenic Muscle Inhibition (AMI) After ACL Reconstruction in Patients With Conventional Rehabilitation or Conventional Rehabilitation Combined With Digital Therapy
ACL - Anterior Cruciate Ligament Rupture
Not yet recruiting
Effects of Early Rehabilitation Using Blood Flow Restriction and/or Surface Electromyography Biofeedback on Quadriceps Activation and Strength After Anterior Cruciate Ligament Reconstruction: A Multicenter Randomized Controlled Trial
Anterior Cruciate Ligament Injuries, Knee Injuries
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Sylvain SB BELOT, MD principal investigator
Hôpitaux Paris Est Val-de-Marne (HPEVM)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Visual Surface EMG Biofeedback and Standard Rehabilitation Without Visual Biofeedback in people with Arthrogenic Muscle Inhibition and Knee Injuries, run by Hopitaux de Saint-Maurice at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage Deviation From the Target Quadriceps Activation Level (time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Oct 2026.