Anterior knee pain in runners- the old tracking on the car analogy.
Today we are looking at another common injury we see in runners- patella femerol joint pain (PFJP). This is pain at the front of the knee, around the area of the knee cap that is typically aggravated by squatting, stairs, running and jumping. Long sitting and pressure on the knee cap can also be painful and there may be some co- existing grinding sounds and a small amount of swelling.
There are currently three areas of focus in the research as to what causes PFJP. The most popular theory is maltracking or mal-alignment of the patella relative to the underlying femur- this reduces surface area and increases subsequent load to subchondral bone. This has been shown using MRI studies and finite element analysis. The neural model looks at neurochemicals in the retinaculum of the knee and ensuing changes to the vascular network. Finally the tissue homeostasis model looks at mechanical loading and chemical irritation to nerve endings.
Biomechanics, local (quads) and proximal (glutes) strength and training load are all important features of PFJP. The 2016 PFJ consensus statement recommends exercises therapy, combining hip and knee exercises and combined interventions in its treatment. Foot orthoses can be useful to reduce pain in the short term, mobilization and electrophysical agents are not recommended.
Exercises should be prescribed according to the specific physiological goal (motor control, work capacity, strength, power and neuromuscular control), ensuring appropriate intensity, volume and frequency. There is some evidence for running retraining in PFJP using internal and external cues (including cadence) to help optimize biomechanics and reduce load to these sensitized tissues.
Again we would recommend you book a Physio appointment. PFJP is a clinical diagnosis and other pathologies need to excluded to ensure appropriate management. Running biomechanics, training load and strength can then be assessed specific to you.