Patella femoral instability can be either primary or secondary. Primary instability is occurs during a traumatic dislocation and results in a tearing of the medial patellofemoral ligament. Secondary instability may occur after a primary dislocation and is similar in nature to patellofemoral pain but tends to be associated with small deviations where the knee cap feels like it is slipping. These episodes can become worse with increasing activity. Secondary instability is normally managed in a similar way to patellofemoral pain. The physiotherapy objective with this condition is to reduce swelling and improve muscle control around the knee to reduce the likelihood of further episodes.