Examination of knee is 4-fold;
· Observation: joint appearance is usually normal but there appears to be slight effusion.
· Mobility: passive movements are usually painless and free, but repeated extension of knee from flexion will produce pain and a grating feeling underneath the patella, especially if the articular surfaces are compressed together.
· Feel: pain and crepitus will be felt if the patellae is compressed against the femur, either vertically or horizontally, with the knee in full extension. By displacing the patellae medially or laterally, the patellar margins and their articular surfaces may be felt. Resisting a static quadriceps contraction will generally produce a sharp pain under the patella.
· X-rays: In most of the cases there is no convincing radiological change. In the later stages, patellofemoral joint space narrows and osteoarthritic changes begin to appear.
There are specific tests for anterior knee pain syndrome;
· Patellar grind test or Clark’s sign – The test detects the presence of patellofemoral joint disorder. A positive sign on this test is pain in patellofemoral joint.
· Extension- resistance test – This test is used to provide a maximal provocation on the muscle-tendon mechanism of the extensor muscles and is positive when the affected knee demonstrates less power when trying to maintain pressure.
· Compression test.