Effect of Surface EMG Biofeedback on Quadriceps Inhibition Release During Postoperative Knee Rehabilitation (BIOQUAD)

August 17, 2026 updated by: Hopitaux de Saint-Maurice

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.

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

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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 Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
5

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • France
      • Saint-Maurice, France, 94410
        • Hôpitaux Paris Est Val-de-Marne - Service de rééducation orthopédique et traumatologie
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Visual sEMG Biofeedback
Participants perform standardized rehabilitation exercises with real-time visual surface electromyography biofeedback.
Behavioral: Visual Surface EMG Biofeedback
Participants perform standardized rehabilitation exercises while receiving real-time visual feedback of quadriceps muscle activity using surface electromyography (sEMG)
Active Comparator: No Visual 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 the same standardized rehabilitation exercises without visual biofeedback. Surface electromyography signals are recorded but are not displayed to the participant.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
During each of the 8 rehabilitation sessions, over approximately 3 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Time Spent Within the Target Quadriceps Activation Zone
Time Frame: During each of the 8 rehabilitation sessions, over approximately 3 weeks
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.
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
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.
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
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
At the beginning 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
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.
At the end 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
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.
At the end of each of the 8 rehabilitation sessions, over approximately 3 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hopitaux de Saint-Maurice

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Sylvain SB BELOT, MD, Hôpitaux Paris Est Val-de-Marne (HPEVM)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 24, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 30, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026-A00944-47

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

No plan to make individual participant data available to other researchers.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings