Anterior knee pain also referred to as "patellofemoral pain syndrome" is a common presentation I see at Acland Street Physiotherapy on a daily basis. It can often be referred to as "runner's knee" as it is a common injury presented in the running population due to oversuse. The patella is the knee cap while the femur is the thigh bone. The joint between the knee cap and thigh bone is called the patellofemoral joint, which acts as a lever in support of movement of your knees. During movement of the knees, the patella works by running up and down smoothly along the groove. The stability and control of this joint is primarily dependent on the biomechanical balance between the static and dynamic supporting soft tissue structures around it.
These soft tissue structures that are important to note that the ITB (iliotibial band) which is on the outside of the knee and the inner quadriceps muscle VMO (vastus medialis oblique) which is on the inside of the knee. An imbalance of these structures can lead to patello maltracking issues, causing movement dysfunction and the patella not running smoothly up and down in its groove. In addition to the knee, this involves a physical assessment of trunk control, hips and feet.
Often, this condition responds well to addressing overall lower limb biomechanics, patella taping, balance (proprioception) exercises, inner quadriceps activation and strengthening exercises, manual release of tight soft tissue structures in particular the ITB and TFL (tensor fascia latae).
An interesting insight based on my experience is that on many patient presentations, those who have tried to alleviate or treat patellofemoral pain syndrome have ignored hip strengthening exercises. A high quality research study (systematic review) in 2015 demonstrated that hip strengthening exercises can significantly reduce the intensity of pain as well as improve function and mobility.