Effect of Surface EMG Biofeedback on Quadriceps Inhibition Release During Postoperative Knee Rehabilitation
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Visual Surface EMG Biofeedback, Standard Rehabilitation Without Visual Biofeedback.
- Who it may be relevant to
- Registry conditions: Arthrogenic Muscle Inhibition, Knee Injuries, Postoperative Rehabilitation. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Effet du Biofeedback Par EMG de Surface Sur la levée d'Inhibition du Quadriceps en rééducation Post-opératoire du Genou
Overview
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.
Interventions
- Behavioral Visual Surface EMG Biofeedback
Participants perform standardized rehabilitation exercises while receiving real-time visual feedback of quadriceps muscle activity using surface electromyography (sEMG) - Behavioral Standard Rehabilitation Without Visual Biofeedback
Participants perform the same standardized rehabilitation exercises without visual biofeedback. Surface electromyography signals are recorded but are not displayed to the participant.
Primary outcome measures
- Percentage Deviation From the Target Quadriceps Activation Level [Time frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks]
Secondary outcome measures (5)
- 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]
Eligibility criteria
Inclusion criteria
- 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
Exclusion criteria
- 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Open label
- Primary purpose
- Treatment
Study locations
France · 1 center
- Hôpitaux Paris Est Val-de-Marne - Service de rééducation orthopédique et traumatologie — Saint-Maurice
Identifiers
NCT: NCT07736625 · 2026-A00944-47