Conditioning Brain Responses to Improve Thigh Muscle Function After Anterior Cruciate Ligament Reconstruction

Study Overview
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Brief Summary
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The purpose of this study is to examine if thigh muscle weakness and the lack of muscle activation that accompanies ACL injury can be improved through a form of mental coaching and encouragement, known as operant conditioning.

Detailed Description
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Thigh muscle weakness is a common result after anterior cruciate ligament (ACL) injury and reconstruction surgery. Therefore, reducing thigh muscle weakness after ACL injury and reconstructive surgery is important as the quadriceps muscles act as shock absorbers that protect the knee joint. If significant weakness is present in the quadriceps, the knee is exposed to increased forces and often results in degeneration of the structures in the joint leading to osteoarthritis. Thus, it is important to investigate activation and strength rehabilitation methods for the quadriceps muscles. This research study is being done to learn if thigh muscle weakness and the lack of muscle activation that accompanies ACL injury can be improved by conditioning brain responses (elicited by non-invasive transcranial magnetic stimulation) using a form of training called as operant conditioning.

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

Conditions
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Anterior Cruciate Ligament Injury

Intervention / Treatment
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* Behavioral: Operant Conditioning
* Behavioral: Control
* Device: Single Pulse Transcranial Magnetic Stimulation


Participation Criteria
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Eligibility Criteria
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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;

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Operant Conditioning<br>Participants will receive operant conditioning training and single pulse transcranial magnetic stimulation 2-3 times a week for about 8 weeks. | Behavioral: Operant Conditioning<br>* Active encouragement and feedback to increase motor evoked response when stimulated.<br>Device: Single Pulse Transcranial Magnetic Stimulation<br>* Transcranial magnetic stimulation to elicit a motor evoked response from the quadriceps muscles.<br>|
| Experimental: Control<br>Participants will receive single pulse transcranial magnetic stimulation 2-3 times a week for about 8 weeks without operant conditioning training. | Behavioral: Control<br>* Absence of active encouragement and feedback to increase motor evoked response when stimulated.<br>Device: Single Pulse Transcranial Magnetic Stimulation<br>* Transcranial magnetic stimulation to elicit a motor evoked response from the quadriceps muscles.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Quadriceps muscle strength | Quadriceps strength will be measured using an isokinetic dynamometer. Improvements in quadriceps strength from baseline to the end of intervention will be assessed and compared between groups. | Approximately 8 weeks after the start of intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in voluntary activation | Voluntary activation will be measured using an electrical superimposition technique. Improvements in voluntary activation from baseline to the end of intervention will be assessed and compared between groups. | Approximately 8 weeks after the start of intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Quadriceps activation deficits, ACL, Surgery, Quadrcieps weakness, Operant conditioning, Cortical excitability