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

NCT ID: NCT03209531

Last Updated: 2025-11-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 11 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-09-21
• Study Completion Date: 2025-11-24

Brief Summary

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

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.

Conditions

Anterior Cruciate Ligament Injury

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Operant Conditioning

Participants will receive operant conditioning training and single pulse transcranial magnetic stimulation 2-3 times a week for about 8 weeks.

Group Type: EXPERIMENTAL

Operant Conditioning

Intervention Type: BEHAVIORAL

Active encouragement and feedback to increase motor evoked response when stimulated.

Single Pulse Transcranial Magnetic Stimulation

Intervention Type: DEVICE

Transcranial magnetic stimulation to elicit a motor evoked response from the quadriceps muscles.

Control

Participants will receive single pulse transcranial magnetic stimulation 2-3 times a week for about 8 weeks without operant conditioning training.

Group Type: EXPERIMENTAL

Control

Intervention Type: BEHAVIORAL

Absence of active encouragement and feedback to increase motor evoked response when stimulated.

Single Pulse Transcranial Magnetic Stimulation

Intervention Type: DEVICE

Transcranial magnetic stimulation to elicit a motor evoked response from the quadriceps muscles.

Interventions

Operant Conditioning

Active encouragement and feedback to increase motor evoked response when stimulated.

Intervention Type: BEHAVIORAL

Control

Absence of active encouragement and feedback to increase motor evoked response when stimulated.

Intervention Type: BEHAVIORAL

Single Pulse Transcranial Magnetic Stimulation

Transcranial magnetic stimulation to elicit a motor evoked response from the quadriceps muscles.

Intervention Type: DEVICE

Eligibility 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;

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Michigan

OTHER

Sponsor Role: lead

Medical University of South Carolina

OTHER

Sponsor Role: collaborator

National Center of Neuromodulation for Rehabilitation

OTHER

Sponsor Role: collaborator

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

NIH

Sponsor Role: collaborator

Responsible Party

Chandramouli Krishnan

Director of Neuromuscular and Rehabilitation Robotics Laboratory

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Chandramouli Krishnan, PhD

Role: PRINCIPAL_INVESTIGATOR

Assistant Professor

Locations

University of Michigan

Ann Arbor, Michigan, United States

Countries

United States

Other Identifiers

P2CHD086844

Identifier Type: NIH

Identifier Source: secondary_id

View Link

HUM00130845

Identifier Type: -

Identifier Source: org_study_id