Improving thigh muscle function after ACL reconstruction using brain conditioning

Operant Conditioning of Motor Evoked Responses to Improve Quadriceps Function in Individuals With Anterior Cruciate Ligament Reconstruction

NA · University of Michigan · NCT03209531

This study is testing if a brain training technique can help people recover stronger thigh muscles after ACL surgery.

Quick facts

PhaseNA
Study typeInterventional
Enrollment12 (estimated)
Ages18 Years to 45 Years
SexAll
SponsorUniversity of Michigan (other)
Locations1 site (Ann Arbor, Michigan)
Trial IDNCT03209531 on ClinicalTrials.gov

What this trial studies

This study investigates whether operant conditioning, a form of mental coaching, can enhance thigh muscle activation and strength following anterior cruciate ligament (ACL) reconstruction. The research focuses on addressing quadriceps weakness, a common consequence of ACL injuries, which can lead to further knee joint issues. Participants will undergo non-invasive transcranial magnetic stimulation to condition brain responses and improve muscle function. The goal is to determine the effectiveness of this approach in reducing muscle activation deficits post-surgery.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 18-45 who have suffered an acute, complete ACL rupture and have undergone ACL reconstructive surgery.

Not a fit: Patients with previous ACL injuries, significant knee issues, or certain medical conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly improve recovery outcomes for patients undergoing ACL reconstruction by enhancing muscle function and reducing the risk of joint degeneration.

How similar studies have performed: While the use of operant conditioning in this context is relatively novel, similar approaches in rehabilitation have shown promise in other studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* aged 18-45 years
* suffered an acute, complete ACL rupture
* have undergone ACL reconstructive surgery
* willingness to participate in testing and follow-up as outlined in the protocol

Exclusion Criteria:

* have suffered a previous ACL injury;
* have undergone previous major surgery to either knee;
* have a history of recent significant knee injury (other than ACL) or lower-extremity fracture;
* have a history of uncontrolled diabetes or hypertension;
* be pregnant or plan to become pregnant;
* have metal implants in the head;
* have electronic devices in their ear or heart (e.g., cochlear implants or cardiac pacemakers);
* have unexplained recurrent headaches;
* have a recent history of seizures;
* be taking drugs that reduce seizure threshold;
* have a history of repeated fainting spells;

Where this trial is running

Ann Arbor, Michigan

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Anterior Cruciate Ligament Injury, Quadriceps activation deficits, ACL, Surgery, Quadrcieps weakness, Operant conditioning, Cortical excitability

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.