• Pain is usually under or around the kneecap, which can be on one or both legs.
• Prolonged sitting, squatting, kneeling, running, jumping, climbing or walking down stairs aggravates pain.

     Causes:

• Many factors may contribute to the development of patellofemoral pain syndrome. The large group of thigh muscles (quadriceps muscles) attach to the kneecap (patella), thus controlling the movement of the kneecap. The kneecap glides through the groove in the thigh bone (femur), increasing the force of the quadriceps muscles with bending and straightening of the knee.
• Overuse, overload, repeated bending of the knee, along with other weight bearing activities may increase pressure between the kneecap and the thigh bone, irritating the undersurface of the knee (articular cartilage), leading to its degeneration, which can cause great pain. This cartilage degeneration is also known as chondromalacia patellae.
• Muscle imbalances resulting from tightness or weakness of the thigh muscles can also cause abnormal gliding of the knee cap, leading to inflammation and pain.
• Abnormal gliding of the knee cap towards the outside of the groove leads to damage to the cartilage underneath the kneecap.
• Alignment problems are caused if the bones in the lower leg are abnormal, which also causes abnormal gliding of the knee cap within the groove when the knee moves. These include the increased angle between the thigh bone (femur) and shin bone(tibia), flat feet and knock-knees.

Treatment:

• Control pain by resting, taking anti-inflammatory drugs, and using ice packs.
• Modify the activity level to avoid the motions that irritate or overload the knee cap.
• Try non-impact aerobic exercises, such as swimming which will not make the pain worse.
• Stretch tight muscles (quadriceps, iliotibial band and hamstrings).
• Strengthening the muscles of the affected lower extremity, including the hips, may help take pressure off the knee cap.
• Evaluate footwear, changing shoes, or wearing arch supports may improve lower extremity biomechanics by preventing pronation (flattening) of the foot.

• Most people suffering from patellofemoral pain recover fully and are able to resume their previous activites.
• Surgery is prescribed when patellofemoral pain can not be eased with braces, rest or physical therapy. Surgery for chondromalacia or lateral tracking of the knee cap could include an arthroscopy or realignment procedure. An arthroscopy removes fragments of damage kneecap cartilage through a small incision. A realignment procedure reduces abnormal pressure on the cartilage and supporting structures around the front of the knee.

Prevention:

• Stay in shape because good general conditioning is important to controlling and preventing patellofemoral pain. Maintaining a healthy weight to avoid overstressing the knees can also help.
• Stretching before and after running or other exercises will keep the supporting structures around the front of the knee flexible and less likely to be irritated.
• Increase training gradually to avoid sudden changes in intensity which can irritate knees.
• Use proper running gear with good shock absorption and quality construction with a good fit. If you have flat feet, you may need shoe inserts.