Patellofemoral pain, also known as Runner’s Knee, is associated with a dull, aching pain under or around the front of the knee. The pain occurs when walking up or down stairs, kneeling, squatting, and sitting with a bent knee for a long period of time. This condition includes anterior knee pain syndrome, patellofemoral malalignment, and chondromalacia patella. Patellofemoral pain may be caused by soft cartilage under the patella (kneecap), soft tissue around the front of the knee, or referred pain from another area such as the back or hip.
Some patellofemoral pain results when the patella is misaligned (patellofemoral malalignment), which can cause excessive wear on the cartilage of the kneecap. This can lead to softening and breakdown of the cartilage on the patella (chondromalacia patella) and cause pain in the underlying bone and irritation of the synovium (joint lining). Strained tendons are another cause that is common in athletes. Other contributing factors can include inflammation, muscle imbalances such as weak quadriceps muscles, tight hamstrings or calf muscles and pronation, or flat, feet.