What Are the Signs, Symptoms and Causes of Runners Knee?

Runner's knee is a common injury among runners and other athletes alike. Runner's knee is a general term that refers to the pain around the knee that runners feel during activity, but the medical term is patellofemoral pain syndrome (PFPS). PFPS is the most prevalent knee ailment among athletes and active adults. Signs and symptoms include a dull ache around or under the patella (kneecap) while running, walking, or kneeling for extended periods of time, or pain that worsens when going up or down stairs. Swelling, popping, or a grinding sensation are also common characteristics of Runner's Knee.



PFPS is usually not caused by one incident, but happens over time. Often, symptoms occur during overuse of the knee, such as continuous bending and loading, or pounding, such as running on pavement. This irritates the nerves and tendons around the knee, creating pain.

Overuse alone is not the only culprit, however. Abnormal patellofemoral tracking is when the kneecap does not move correctly within the joint, causing pain. Several factors that may cause abnormal tracking include skeletal abnormalities such as misalignment of the patella, genu varum (bowleg) and genu valgum (knock-knee), strength imbalance in the quadriceps (thigh) muscles and surrounding structures, and abnormal movement of the foot.

Muscle imbalance and muscle weakness are large contributors to developing PFPS as well. Research shows that novice runners are at a greater risk of developing Runner's Knee, especially if they have weak hip muscles, weak quadriceps muscles and/or an imbalance of strength within the quadriceps muscles. This weakness and imbalance changes the forces and weight exerted on the patella causing it to shift and creating more pain. Improper stretching and muscle tightness can also pull on the patella.

Foot movement is an additional cause of knee pain. If the foot moves in a way that does not allow for proper shock absorption, the shock is felt in the knee. The knee is not capable of sustaining that level of force, and will retaliate with pain.

While Runner's Knee sounds like a simple and single issue, the actual medical diagnosis of PFPS is often caused by a multitude of events that has taken place over a period of time. Each individual's body is connected as a whole, which means if one part is unbalanced, another part will likely suffer. A sufferer may be a runner, but is just as likely be a skier, jumper, cyclist, or basketball or soccer player.