Neuromuscular Control in Individuals Following ACL-Reconstruction
Condition: Anterior Cruciate Ligament Injuries; Quadriceps Muscle Atrophy
MeSH terms: Muscular Atrophy; Anterior Cruciate Ligament Injuries
Study type: Interventional

Summary: 
      The purpose of this study is to investigate the neurophysiological contributors to muscle
      function following ACL Reconstruction and the influence of motor control biofeedback exercise
      on measures of muscle function. The research team hypothesizes that the application of motor
      biofeedback will increase cortical excitability of the quadriceps compared to the passive
      movement of the knee.

      This is a single session cross-over intervention study with a 1-week washout period between
      treatment arms.
    

Detailed description: 
      1. Pre-treatment neuromuscular assessment Cortical Active Motor Threshed We will measure
           motor evoked potentials with the use of a Transcranial magnetic stimulator (MagStim
           model 200, Magstim Co., Ltd., Wales, UK). The MagStim has FDA 510K Clearance for
           stimulation of peripheral nerves.

             -  The participant will be asked to sit in the dynamometer (Biodex, System 3) in knee
                extension at 90 degrees of knee flexion.

             -  EMG electrodes will be placed on the distal quadriceps

                o Local shaving, debridement, and cleaning will be done prior if necessary

             -  A non-latex swim cap will be placed on the participants head for investigator's
                measurements

             -  Briefly, a magnetic field with a maximum value of 2.2 Tesla will be introduced to
                the scalp at a location in the pre-motor cortex that corresponds to the quadriceps.
                Single pulse stimulations will be delivered with no less than 10 seconds between
                stimulations (maximum = 0.1 Hz).

             -  When the magnetic field is received at the premotor cortex at the appropriate area,
                a motor signal is sent to the quadriceps. We will record this signal with surface
                EMG electrodes that are on the quadriceps.

             -  The participant will be asked to extend their leg to match a force equivalent to 5%
                MVIC. Feedback will be provided to the participant to provide such force.

             -  Stimulation of the TMS will happen once every ten seconds until the Active Motor
                Threshold was found by the investigator.

                  -  The motor evoked potential measured by the quadriceps will be recorded at 80%,
                     90%, 100%, 110%, 120%, 130%, 140%, and 150% of the patients Active motor
                     threshold.

        2. Patient randomization

           - The patient is then randomized to 1 of 2 treatment arms. 1) Visuomotor Therapy or 2)
           Passive Motion

        3. Perform Randomized Treatment Visuomotor Therapy

             -  The participant will sit in the Biodex chair with the tested limb secured in the
                dynamometer

             -  The participant will receive live real-time biofeedback of their knee force output
                (no more than 30% of maximum force)

             -  The participant will aim to match their force output to a target threshold
                presented on the screen.

             -  The participant will complete 10 60-second trials of this exercise with a 30 second
                rest between each trial.

           OR

           Passive Motion

             -  The participant will sit in the Biodex chair with the tested limb secured in the
                dynamometer

             -  The dynamometer will passively move the patients lower limb between 80 to 120
                degrees of knee flexion

             -  The participant will be asked to relax for the duration of testing - The
                participant will complete 10 60-second trials of this exercise with a 30 second
                rest between each trial.

        4. Reassess Neuromuscular outcome (Step 1)

        5. 1-week washout period

        6. Repeat Steps 1 through 4 but the patient receives the cross-over arm intervention
    

Intervention name(s): Visuomotor Therapy; Passive Motion
Intervention type(s): Other; Other
Intervention description(s): The use of visual feedback informing internal physiological processes, such as muscle activation, torque, and joint position, has been termed "visuomotor therapy". Visuomotor therapy encompasses completion of sub-maximal motor control tasks accompanying real-time visual biofeedback.; The knee is passively moved through a range of motion.
Other intervention name(s): Motor Biofeedback
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Laboratory Controlled Crossover Study
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment