Patellofemoral joint (PFJ) pain is one of the most common knee complaints in runners and the highest presenting knee pathology to physiotherapists. Patients may commonly describe pain at the front of the knee aggravated by stairs and weight bearing or jarring activities that involve knee bending.

PFJ pain is commonly caused by poor kneecap alignment – where the kneecap does not glide freely through the femoral groove. This causes joint irritation and sometimes degeneration behind the kneecap as the kneecap rubs against the femur.

The malalignment or maltracking of the patella as we bend the knee is caused by a number of factors, the most common causes being a muscle imbalance and poor biomechanics.

Below is a breakdown of the contributing risk factors.

Internal

  • Structural abnormalities – femoral ante-version, shallow femoral groove, genu valgus (knock knees), patella alta (high sitting patella), leg length discrepancy.
  • Poor foot and hip biomechanics – flat feet, high arches, increased Q angle.
  • Muscle weakness – gluteals, VMO.
  • Hip and ankle muscle tightness and/or joint stiffness – such as tight ITB and decreased ankle dorsi flexion.
  • Poor balance and coordination.
  • Poor shock absorption when landing.
  • Gender – more likely in females.
  • Previous lower limb injuries.

External

  • High impact sports.
  • Training/playing surfaces.
  • Training load.
  • Equipment.
  • Footwear.

Common sports where PFJ pain is typically seen includes those with excessive running, jumping and squatting such as long distance running, netball, football, tennis, volleyball, basketball and skiing.

Untreated PFJ pain can result in patella tendonitis or other biomechanical related injures of the lower limb. Physiotherapy treatment to enable a patient to return to their chosen sport may involve:

  • Ice and anti-inflammatories
  • Regaining full range of movement
  • Restoring muscle length
  • Normalising quadriceps muscle control
  • Correcting hip and foot biomechanics
  • Retraining sport specific movement patterns by adding power, speed and agility

References:

(Crossley., Collins., Beller., 2008)., (Brukner & Khan., 2005)., (McConnell., 2000)