NCT03209531

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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
11

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Sep 2017

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

June 30, 2017

Completed
6 days until next milestone

First Posted

Study publicly available on registry

July 6, 2017

Completed
3 months until next milestone

Study Start

First participant enrolled

September 21, 2017

Completed
8.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 24, 2025

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

November 24, 2025

Completed
Last Updated

November 26, 2025

Status Verified

November 1, 2025

Enrollment Period

8.2 years

First QC Date

June 30, 2017

Last Update Submit

November 25, 2025

Conditions

Anterior Cruciate Ligament Injury

Keywords

Quadriceps activation deficitsACLSurgeryQuadrcieps weaknessOperant conditioningCortical excitability

Outcome Measures

Primary Outcomes (1)

  • 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 Outcomes (1)

  • Changes in voluntary activation

    Approximately 8 weeks after the start of intervention

Other Outcomes (8)

  • Changes in mid-point quadriceps muscle strength

    Approximately 4 weeks after the start of intervention (mid-time point evaluation)

  • Changes in mid-point voluntary activation as measured by percentage activation deficit

    Approximately 4 weeks after the start of intervention (mid-time point evaluation)

  • Changes in motor cortical excitability measures

    Approximately after 8 weeks after the start of intervention

  • +5 more other outcomes

Study Arms (2)

Operant Conditioning

EXPERIMENTAL

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

Behavioral: Operant ConditioningDevice: Single Pulse Transcranial Magnetic Stimulation

Control

EXPERIMENTAL

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

Behavioral: ControlDevice: Single Pulse Transcranial Magnetic Stimulation

Interventions

Operant ConditioningBEHAVIORAL

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

Operant Conditioning
ControlBEHAVIORAL

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

Control
Single Pulse Transcranial Magnetic StimulationDEVICE

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

ControlOperant Conditioning

Eligibility Criteria

Age18 Years - 45 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • 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

You may not qualify if:

  • 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;

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48108, United States

Location

MeSH Terms

Conditions

Anterior Cruciate Ligament Injuries

Interventions

Transcranial Magnetic Stimulation

Condition Hierarchy (Ancestors)

Knee InjuriesLeg InjuriesWounds and Injuries

Intervention Hierarchy (Ancestors)

Magnetic Field TherapyTherapeutics

Study Officials

  • Chandramouli Krishnan, PhD

    Assistant Professor

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Director of Neuromuscular and Rehabilitation Robotics Laboratory

Study Record Dates

First Submitted

June 30, 2017

First Posted

July 6, 2017

Study Start

September 21, 2017

Primary Completion

November 24, 2025

Study Completion

November 24, 2025

Last Updated

November 26, 2025

Record last verified: 2025-11

Locations

US(1)