ACL - Anterior Cruciate Ligament RuptureAMIMYONCT07659561
Assessment of Electromyographic Activity in the Quadriceps and Hamstrings of the Operated Limb Versus the Unaffected Limb in Patients Who Have Undergone ACL Surgery, With and Without Post-operative AMI - an Exploratory Study
A study testing Electromyography in people with ACL - Anterior Cruciate Ligament Rupture, run by GCS Ramsay Santé pour l'Enseignement et la Recherche at 1 site in France.
Trial summary
Traumatic injuries to the knee joint, such as an anterior cruciate ligament tear, can compromise the ability of the muscle at the front of your thigh-known as the quadriceps-to contract voluntarily, despite the anatomical integrity of the nerve and muscle structures responsible for contraction. Read more about this study
- Who is it for?
- Ages 18 to 45 years
- Conditions the study is for
- ACL - Anterior Cruciate Ligament Rupture
- What is being tested?
- Electromyography
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteFrance
- Study dates
- Sep 2026to Oct 2027
- 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 to 45 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patient who has undergone ACL surgery at least 3 weeks ago
- Patient with no severe knee inflammation: stroke test ≤ 1+ and pain ≤ 3/10 (EN) at rest
- Patient with a Tegner score ≥ 5
- Patient with a Marx score ≥ 8
- Patient with or without a diagnosis of subjective AMI (Sonnery-Cottet et al. classification)
- French-speaking patients who do not object to the use of their data
Who cannot join
- Patient with a previous injury or surgery to the same or opposite knee
- Patient with a multi-ligament injury
- Patient with an AMI > grade 2b (Sonnery-Cottet et al. classification)
- Patient with a BMI > 30
- Pregnant or breastfeeding woman
- Patient with previous or current neurological and cardiovascular disorders or diseases
- Patient under legal protection: adult under guardianship, curatorship or other legal protection, deprived of liberty by judicial or administrative decision
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Hôpital Privé Jean Mermoz
Lyon, 69008
Bertrand SONNERY-COTTET, MD, + 33 4 37 53 00 22, sonnerycottet@aol.com
About this study
Traumatic injuries to the knee joint, such as an anterior cruciate ligament tear, can compromise the ability of the muscle at the front of your thigh-known as the quadriceps-to contract voluntarily, despite the anatomical integrity of the nerve and muscle structures responsible for contraction. This phenomenon, commonly known as 'arthrogenic motor inhibition' (AMI), is a major limiting factor for recovery and rehabilitation following an anterior cruciate ligament tear, as well as a potential cause of functional disability if left undiagnosed and untreated. Indeed, motor inhibition that persists during the early months of rehabilitation could lead to under-activation of the quadriceps and over-activation of the hamstrings (the muscles at the back of your thigh).
It is of interest to assess, during the rehabilitation phase, the contraction capacity of the various quadriceps and hamstring muscles in the operated limb compared with the unaffected limb in patients who have undergone anterior cruciate ligament surgery and who experience post-operative motor inhibition, and in patients who have undergone anterior cruciate ligament surgery but do not experience post-operative motor inhibition. This is why this study has been initiated.
Read the detailed description
An ACL tear and reconstruction can lead to a neurophysiological dysfunction commonly known as 'arthrogenic muscle inhibition' (AMI). This phenomenon impairs the ability to voluntarily activate the quadriceps, despite the anatomical integrity of the nerve and muscle structures responsible for contraction.
AMI is responsible for the quadriceps deficits observed following an ACL rupture and thus appears to be a major limiting factor in the patient's rehabilitation and functional recovery. Consequently, its diagnosis and treatment are imperative. The diagnosis of AMI (post-rupture and post-operative) is based on a classification system that categorises AMI diagnoses according to the identification of a deficit in activation of the vastus medialis (VM) alone (grade 1) or in combination with an extension deficit due to a grade 2 hamstring contracture (grade 2) (Sonnery-Cottet et al, 2022).
During the clinical examination, normal VM contraction (during relaxation) can be achieved without the recruitment of all motor units (minimal VM activation), and full knee extension (i.e. without reflex contraction of the hamstrings) can be restored without a return to adequate hamstring activation for the required task. Deficits in activation (inadequate activation) of the quadriceps and over-activation of the hamstrings (Hamstrings) during movements involving greater forces could be the consequences of an AMI still present in the early months of rehabilitation. This AMI could then disrupt the electromyographic (EMG) activation patterns of the quadriceps and hamstrings and contribute to long-term quadriceps deficits.
In this context, it is of interest to assess, during the rehabilitation phase, the EMG activity of the different muscle heads of the quadriceps and hamstrings in the operated limb versus the healthy limb in patients who have undergone ACL surgery and experienced post-operative IMA, and in patients who have undergone ACL surgery without post-operative IMA.
No studies have been published on this topic. This is why this research has been initiated.
- Conditions
- ACL - Anterior Cruciate Ligament Rupture
- Being tested
- Electromyography
- Keywords
- ACL rupture, AMI, electromyography, thigh
- Medical subject headings
- Anterior Cruciate Ligament Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ElectromyographyBehavioural
Surface EMG of the quadriceps (vastus medialis, vastus lateralis and vastus longus) and the semimembranosus and biceps femoris muscles of the hamstrings on both the affected and unaffected sides, to objectively assess quadriceps inhibition.
| Study group | Role | What they receive |
|---|---|---|
| ACL Arm | Experimental | Patient with ACL rupture Receives: Behavioral: Electromyography |
What is being measured
The primary outcome is the main question the study is designed to answer.
EMG activity
The average amplitude of EMG activity in the VM (Vastus Medialis) is assessed using the Root Mean Square (RMS) value, which is expressed in millivolts (mV). The RMS is recorded using surface electrodes placed on the vastus medialis. The primary outcome measure (activation deficit) is the absolute difference in RMS between the operated leg and the unaffected leg.
Measured: Month 3
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jun 2026
- Study startSep 2026 (estimated)
- Primary completionOct 2027 (estimated)
- Study completionOct 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ACL - Anterior Cruciate Ligament RuptureStudies of the same condition, open and under way.
- More trials run by GCS Ramsay Santé pour l'Enseignement et la RechercheThe sponsor's other registered studies.
- 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07659561
- Sponsor's protocol ID
- 2026-A00008-43
- Acronym
- AMIMYO
- Status last verified
- Jun 2026
- First submitted
- 15 Jun 2026
- Last updated
- 22 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Electromyographic Activity in the Quadriceps and Hamstrings of the Operated Limb Versus the Unaffected Limb in Patients Who Have Undergone ACL Surgery, With and Without Post-operative AMI - an Exploratory Study
- ClinicalTrials.gov ID
- NCT07659561
- Acronym / sponsor ID
- AMIMYO / 2026-A00008-43
- Conditions
- ACL - Anterior Cruciate Ligament Rupture
- Keywords
- ACL rupture, AMI, electromyography, thigh
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- GCS Ramsay Santé pour l'Enseignement et la RechercheUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Oct 2027 (estimated)
- Study completion
- Oct 2027 (estimated)
- First posted
- 22 Jun 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.
Traumatic injuries to the knee joint, such as an anterior cruciate ligament tear, can compromise the ability of the muscle at the front of your thigh-known as the quadriceps-to contract voluntarily, despite the anatomical integrity of the nerve and muscle structures responsible for contraction. This phenomenon, commonly known as 'arthrogenic motor inhibition' (AMI), is a major limiting factor for recovery and rehabilitation following an anterior cruciate ligament tear, as well as a potential cause of functional disability if left undiagnosed and untreated. Indeed, motor inhibition that persists during the early months of rehabilitation could lead to under-activation of the quadriceps and over-activation of the hamstrings (the muscles at the back of your thigh).
It is of interest to assess, during the rehabilitation phase, the contraction capacity of the various quadriceps and hamstring muscles in the operated limb compared with the unaffected limb in patients who have undergone anterior cruciate ligament surgery and who experience post-operative motor inhibition, and in patients who have undergone anterior cruciate ligament surgery but do not experience post-operative motor inhibition. This is why this study has been initiated.
Detailed description
An ACL tear and reconstruction can lead to a neurophysiological dysfunction commonly known as 'arthrogenic muscle inhibition' (AMI). This phenomenon impairs the ability to voluntarily activate the quadriceps, despite the anatomical integrity of the nerve and muscle structures responsible for contraction.
AMI is responsible for the quadriceps deficits observed following an ACL rupture and thus appears to be a major limiting factor in the patient's rehabilitation and functional recovery. Consequently, its diagnosis and treatment are imperative. The diagnosis of AMI (post-rupture and post-operative) is based on a classification system that categorises AMI diagnoses according to the identification of a deficit in activation of the vastus medialis (VM) alone (grade 1) or in combination with an extension deficit due to a grade 2 hamstring contracture (grade 2) (Sonnery-Cottet et al, 2022).
During the clinical examination, normal VM contraction (during relaxation) can be achieved without the recruitment of all motor units (minimal VM activation), and full knee extension (i.e. without reflex contraction of the hamstrings) can be restored without a return to adequate hamstring activation for the required task. Deficits in activation (inadequate activation) of the quadriceps and over-activation of the hamstrings (Hamstrings) during movements involving greater forces could be the consequences of an AMI still present in the early months of rehabilitation. This AMI could then disrupt the electromyographic (EMG) activation patterns of the quadriceps and hamstrings and contribute to long-term quadriceps deficits.
In this context, it is of interest to assess, during the rehabilitation phase, the EMG activity of the different muscle heads of the quadriceps and hamstrings in the operated limb versus the healthy limb in patients who have undergone ACL surgery and experienced post-operative IMA, and in patients who have undergone ACL surgery without post-operative IMA.
No studies have been published on this topic. This is why this research has been initiated.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| ACL Arm | Experimental | Behavioral: ElectromyographyPatient with ACL rupture |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Patient who has undergone ACL surgery at least 3 weeks ago
- Patient with no severe knee inflammation: stroke test ≤ 1+ and pain ≤ 3/10 (EN) at rest
- Patient with a Tegner score ≥ 5
- Patient with a Marx score ≥ 8
- Patient with or without a diagnosis of subjective AMI (Sonnery-Cottet et al. classification)
Key exclusion criteria (7 listed)
- Patient with a previous injury or surgery to the same or opposite knee
- Patient with a multi-ligament injury
- Patient with an AMI > grade 2b (Sonnery-Cottet et al. classification)
- Patient with a BMI > 30
- Pregnant or breastfeeding woman
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 |
|---|---|---|
| ElectromyographySurface EMG of the quadriceps (vastus medialis, vastus lateralis and vastus longus) and the semimembranosus and biceps femoris muscles of the hamstrings on both the affected and unaffected sides, to objectively assess quadriceps inhibition. | Behavioural | ACL Arm |
Primary outcome
EMG activity
Time frame: Month 3
The average amplitude of EMG activity in the VM (Vastus Medialis) is assessed using the Root Mean Square (RMS) value, which is expressed in millivolts (mV). The RMS is recorded using surface electrodes placed on the vastus medialis. The primary outcome measure (activation deficit) is the absolute difference in RMS between the operated leg and the unaffected leg.
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 22 Jun 2026.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Electromyography in people with ACL - Anterior Cruciate Ligament Rupture, run by GCS Ramsay Santé pour l'Enseignement et la Recherche 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 6 inclusion and 7 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: opening soon, as of the sponsor's last update on 22 Jun 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?
Contact Bertrand SONNERY-COTTET, MD (+ 33 4 37 53 00 22, sonnerycottet@aol.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
EMG activity (time frame: Month 3). 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 22 Jun 2026.