Sensorimotor Dysfunction after ACL Injury – Injury Population

STUDY BASICS

Have you had an ACL tear with surgical reconstruction? Are you a woman between 18-30 years old? You may be eligible for a research study to understand how the brain changes in response to ACL injury and reconstruction surgery. Compensation is provided.

STUDY PURPOSE

You are invited to participate in a study to determine how anterior cruciate ligament ruptures (ACLR) affect the brain and knee musculature. Years after surgery, rehabilitation, and resuming recreational and athletic activities, many people with ACLR still have performance deficits and are concerned about their knee function and risk of re-injury. We will try to better understand if changes in the brain are related to physical deficits in the knee, such as knee instability. In addition, we will attempt to improve the communication between the leg region of the brain and the knee that had surgery to improve overall knee function. We will use many different tests such as non-invasive brain stimulation (transcranial magnetic stimulation or TMS) and neuroimaging (structural and functional brain images) to understand the relationship between the brain and knee function following ACL injury. 

COULD THIS STUDY BE RIGHT FOR YOU?

Eligible participants:

• Are women 18-30 years old 
• Have had an ACL tear with surgical reconstruction up to 5 years ago
• No metal in body or implanted medical devices, including copper IUD
• Physically active for at least 150 minutes (2.5 hr) per week 
• No history of epilepsy, seizure, or sleep disorders
• No current brain injury, psychiatric, or mental health disorders 
• Not currently taking prescription psychoactive drugs (e.g. anti-depressant, anti-anxiety medication)
• Right-leg dominant 
• No ACL re-tear or torn the other leg's ACL 
• No multi-ligamentous injury, such as both an ACL and MCL tear 
• Not pregnant or trying to get pregnant
• Do not weigh more than 300 lbs

WHAT PARTICIPANTS CAN EXPECT

We will use transcranial magnetic stimulation (TMS) to stimulate your brain non-invasively. For TMS, a coil is placed on your head above the areas of the brain we intend to stimulate. When turned on, the coil produces a strong but brief magnetic field (i.e. pulse) that activates small areas of your brain. We can also examine how your brain communicates with your muscles using muscle activity sensors. During each stimulus, you will feel a light tapping sensation on your head and your muscles will respond, similar to knee reflex examination at the doctor's office. 

In addition, we will also stimulate nerves that control muscles of your hands, calf, and thighs to examine muscle and nerve function. Testing will include measuring the size of your muscles, muscular strength tests, and single-leg balance tests. Electrical pulses will be delivered to your thigh, wrist, and calf nerves that will feel similar to a light poke with a push pin, without actually breaking your skin.