Grant: DRA : Canada Graduate Research Scholarship - Doctoral Program (CGRS D)

Knee osteoarthritis (OA) is a leading cause of disability worldwide. It is often identified by a decay in the knee joint cartilage and bone, and is more common in females compared to males. This can lead to pain, stiffness, muscle weakness, and loss of valued activities (females also experience greater pain severity and physical limitations). Pain is the most disabling symptom, and is what drives people to see a health-care professional. However, changes inside the knee don't fully explain the pain and physical symptoms people experience: people with the same joint changes in the knee may have very different levels of pain and other symptoms, and many individuals with arthritic knee joint changes don't have any symptoms at all. In fact, much of how pain works in knee OA is still puzzling. Research shows that one factor that contributes to this puzzle is changes in how the spinal cord and brain transmit and process pain signals. The brain and spinal cord are also responsible for sending signals back to the muscles to contract. Exploration of the brain to spinal cord to muscle pathway in knee osteoarthritis has been limited, and changes in this pathway may help explain some of the pain and other symptoms people experience. To test this, we will measure how much energy it takes for different parts of the brain to muscle pathway to turn on, and how well different parts of the brain responsible for coordinating signals to muscles are communicating with each other. We will do this using non-invasive brain stimulation, which can directly "excite" nerve cells in the brain. We will compare these findings between people with painful knee OA to people without knee pain, and we'll also see if pain intensity or sex influences the results. This will help us understand how and why different parts of the two-way highway between the knee and brain are affected. Then specific treatments that target these pathways can be developed to improve knee OA pain and other symptoms.