When people say they have “runner’s knee,” they are typically referring to patellofemoral pain syndrome. “Patella” means kneecap and “femur” means thighbone, so patellofemoral pain is pain that originates between the kneecap and thighbone. The pain is felt at the front of the knee, either under or around the edges of the kneecap. The root of patellofemoral pain can vary and may be difficult to identify. For example, the kneecap may not glide well along the groove in the femur (thighbone), or relatively weak hip muscles may cause a runner to over-rely on quadriceps muscles, which then tug uncomfortably on the kneecap. Patellofemoral pain is typically more noticeable going up stairs or walking or jogging uphill.
Iliotibial (IT) band syndrome
Iliotibial band syndrome can affect both novice and experienced runners. The pain tends to be sharp and isolated to the area just above or at the knobby outside of the knee. IT band syndrome does not cause redness, swelling, or knee instability.
The iliotibial band, or IT band, is a thick piece of fibrous tissue that begins at the hip, extends along the outside of the thigh, and attaches to the top of the tibia, or shinbone. When the knee bends, the IT band must glide over the outside of the knee joint, including the bulbous end of the femur called the lateral condyle. If the IT band becomes tight from strain or overuse, it can rub against the lateral condyle and become inflamed, causing pain. Unlike patellofemoral pain syndrome, the IT band pain is often worse when going down stairs or jogging downhill.
Commonly called “jumper’s knee,” patellar tendinitis can cause pain at the front of the knee, at the lower kneecap or the bony bump at the top of the shin. The pain may be minor and felt only when exercising, or it may be severe enough to affect a person’s daily activities, such as going up stairs. Along with pain, a person may notice swelling, redness and warmth.
A tendon connects muscle to bone and a ligament connects bone to bone. The patella tendon is actually a ligament that connects the patella (kneecap) to the upper tibia (shin bone). When the patellar tendon becomes inflamed and causes painful symptoms it is called patellar tendinitis. It tends to be an overuse injury that is common in runners, particularly people who run on downhill inclines, and people who participate in sports that require a lot of starting and stopping.