Chondromalacia is due to an irritation of the undersurface of the kneecap, which normally is covered with a layer of smooth cartilage. This cartilage, when correctly functioning, glides effortlessly across the knee during bending of the joint. However, in some individuals, the kneecap tends to rub against one side of the knee joint, and the cartilage surface becomes irritated.
In adolescents and young adults, patellofemoral pain often is caused by muscle weakness, overuse or injury. Sometimes an unusual alignment of the kneecap is responsible. For older adults, patellofemoral pain may be related to arthritis of the knee joint. Weak thigh and hip muscles or flat feet also may contribute to the pain. Even something as simple as worn-out or ill-fitting shoes can contribute to patellofemoral pain.
Signs and symptoms of patellofemoral pain include: a dull, achy pain in the front of your knee, knee pain after sitting for long periods of time, a grating or grinding sensation when you extend your knee, knee stiffness, and more.