Pains originating from the patello-femoral joint or knee cap (patella) are very common. They can result in diffuse or sharp pains surrounding the knee cap or even behind the knee. They tend to be aggravated by any bent knee activity such as running, kneeling, squatting, sitting for prolonged periods or stairs.
Patello-femoral pain may occur as a result of many factors. In the normal knee, the patella glides up and down through a groove in the bottom end of the femur. When the knee is bent the pressure between the patella and femur is increased. If the patella does not track smoothly through the groove, there is a subsequent increase in pressure and resultant pain and inflammation.
This may result from:
- a muscle imbalance between the inside muscle called the vastas medialis and the outside muscle called the vastas lateralis causing the patella to rub against the femur unevenly
- tight muscles on the outside of the knee (ilio-tibial band)
- a narrow groove in the femur
- pronated or flat feet
The cartilage between the two bones that make up the knee joint acts as a shock absorber. If a strong compressive and rotation force is applied to the knee a tear in the cartilage on either the inside or outside of the knee joint may occur. The resultant swelling will cause pain, restricted movements of the joint and even locking of the knee.
Ligaments connect bone to bone and act to provide stability to a joint. If the joint is moved beyond the ligament’s ability to stretch it may tear. The result will be pain, swelling and the joint will lose some degree of stability depending on the severity of the tear.
Tendons are the end of muscles that connect it to bones. Inflammation of tendons is known as tendonitis and is usually a result of repetitive actions and poor biomechanics of the area affected. It is common for injuries to arise at the front of the knee, known as patella tendonitis, and is usually a result of repetitive jumping or running.
Your physiotherapist will assess your knee and determine the cause of your pain.
Treatment may consist of:
- rest from aggravating activities
- electrotherapy to reduce inflammation and swelling
- mobilisation of the patella or knee joint
- an exercise program to strengthen weak muscles and stretch tight muscles
- patella or knee taping techniques and correction of biomechanical problems