There is no clear definition of anterior knee pain and patients can present with various symptoms. There may be a functional deficit, crepitus and /or instability.
With activities of daily living pain often occurs or worsens when walking down stairs, squatting, depressing the clutch pedal in a car (in the case of left knee pain), wearing high-heeled shoes or sitting for long periods with the knees in a flexed position (‘‘movie sign’’).
Patients also experience a certain degree of instability ‘‘in a straight line’’ especially going up and down stairs or ramps.
Individuals with overuse injuries may report a feeling of instability or giving way, although this may not a true giving way (usually associated with internal injury to the knee) but a neuromuscular inhibition as a result of the pain, muscle weakness, patellar or joint instability