Symptoms of Patellofemoral pain syndrome consist of an aching pain in the knee joint, particularly at the front of the knee around and under the patella.
There is often tenderness along the inside border of the patella (kneecap) and swelling will sometimes occur after exercise. Patellofemoral pain is often worse when walking up and down hills or after sitting for long periods of time.
Other signs include a click or cracking sound when bending the knee. If the condition has been a problem for some time then there is likely to be wasting of the quadriceps muscles as well as tight muscles around the knee joint.
Assessment and diagnosis of patella pain syndrome should include questioning and history as well as a physical examination.
It is important to identify which structures may be causing pain. The therapist will ask questions about the patients history and onset of pain as well as perform a physical assessment. Causes can be extrinsic meaning outside of the body which include increased training loads, types of shoes worn and training surfaces. Or they can be intrinsic meaning from within the body.
A number of tests can be performed to identify what might be causing the pain:
The Q angle of the knee is a measurement of the angle between the quadriceps muscles and the patella tendon and provides useful information about the alignment of the knee joint. To measure the Q angle will need a long-arm goniometer. Place the centre of the goniometer over the centre of the patella and position the bottom arm in line with the patella tendon and tibial tuberosity. Next position the upper arm so that it is pointed directly at the anterior inferior iliac spine (AIIS) of the ilium (point to which rectus Femoris attaches). The small angle of the goniometer is the Q angle.
Patella compression test
Patella grind test