Determining the Effects of Non-invasive Brain Stimulation to Improve Quadriceps Muscle Function After ACL Reconstruction

Purpose

After knee surgery for a torn ACL, many women struggle with weak thigh muscles for years, partly due to reduced brain signals to these muscles. Our research tests a new approach to improve recovery by using low-level brain stimulation to boost these signals. The investigators will study 42 women, aged 18-35, who had ACL surgery. They'll be split into two groups: one receiving real brain stimulation and another getting a placebo, both during thigh-strengthening exercises. Over six sessions, the investigators measure thigh muscle strength, speed, and steadiness, plus two brain signal measures, using special equipment. The investigators will also check if stronger brain signals lead to better muscle performance, especially in women. Our goal is to show that this new method strengthens thigh muscles better than standard rehab, helping women recover better after surgery. If successful, this could improve physical therapy for women recovering from ACL surgery, making daily activities and return to sport easier.

Conditions

  • Anterior Cruciate Ligament Reconstruction Rehabilitation
  • Quadriceps Muscle Function

Eligibility

Eligible Ages
Between 18 Years and 35 Years
Eligible Sex
Female
Accepts Healthy Volunteers
No

Inclusion Criteria

  • females 2-6 months after ACL reconstruction

Exclusion Criteria

  • multiple ligament reconstruction - osteochondral procedures - any previous lower extremity surgery - previous ACL injury - Metal or implants in the head or neck - history of neurological disease - seizures - severe migraines - concussion within the last 6 months

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Intervention Model Description
Triple-blinded randomized controlled trial
Primary Purpose
Treatment
Masking
Triple (Participant, Care Provider, Investigator)

Arm Groups

ArmDescriptionAssigned Intervention
Active Comparator
Active tDCS
This group will receive 20 minutes of active anodal tDCS
  • Device: active transcranial direct current stimulation (tDCS)
    20 minutes of anodal tDCS over the primary motor cortex contralateral to the participants surgical limb during a quadriceps torque matching task
Sham Comparator
Sham tDCS
This group will receive sham anodal tDCS. The tDCS unit will be active for the first 30 seconds and the last 30 seconds only.
  • Device: sham transcranial direct current stimulation (tDCS)
    Participants receive sham tDCS in which the device only delivers current during the first and last 30 seconds while participants perform a quadriceps torque matching task

Recruiting Locations

Ryan Zarzycki
Glenside, Pennsylvania 19038
Contact:
Ryan Zarzycki, PT, PhD
215-572-8527
zarzyckir@arcadia.edu

More Details

Status
Recruiting
Sponsor
Arcadia University

Study Contact

Ryan Zarzycki, PhD
215-572-2852
zarzyckir@arcadia.edu

Detailed Description

Quadricep muscle impairments persist for years after anterior cruciate ligament reconstruction (ACLR). Recent evidence suggests that lower neural drive, (i.e., lower corticospinal excitably (CSE)), is associated with pronounced quadriceps muscle performance deficits, which are more severe in females recovering from ACLR than in males. Current postoperative rehabilitation protocols do not target lower neural drive, which can be achieved through non-invasive brain stimulation. Thus, the long-term goal of this research is to improve the effectiveness of ACLR rehabilitation. The objective of this project is to determine if neural drive is the critical missing link in ACLR rehabilitation. To meet this objective, the investigators will administer anodal transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation known to increase CSE. The investigators will then assess whether it improves three measures of quadriceps muscle performance (in Aim 1) and two measures of CSE (in Aim 2). In Aim 3, the investigators will determine the relationship between observed changes in quadriceps muscle performance and CSE in female participants recovering from ACLR. These aims will be achieved using a randomized, triple-blinded clinical trial with 42 female individuals after ACLR between the ages of 18 and 35 years. All participants will receive six sessions of active or sham anodal tDCS while they perform isolated quadriceps exercises on an isokinetic dynamometer. The two measures of CSE (i.e. active motor threshold and the slope of transcranial magnetic stimulation (TMS) induced recruitment curves) will be determined using surface electromyography on the vastus medialis and TMS. Three measures of quadriceps performance (i.e. peak torque normalized to body weight, rate of torque development (RTD) from 0-100ms and 100-200ms, and torque steadiness) will be determined following standard isometric muscle testing on an isokinetic dynamometer with the hips flexed to 90° and the knees flexed to 60°.