Healthy Life: Knee Pain – Causes and Symptoms (600)

Healthy Life: Knee Pain

蘇鎮邦 (Christopher So)：
舒整物理治療師 (Manipulative Physiotherapist) 人類工程師 (Ergonomist)

The knee joint is made up by four bones into three joints with complicated constructions. The femur and patella form the Patellofemoral joint. The femur and tibia form the Tibiofemoral joint. The fibula and tibia form the Tibiofibular joint. In between the femur and tibia, there are the Anterior and Posterior Cruciate Ligaments which function to stabilize the forward and backward movements of the knee joint, especially during stair climbing and stop-and-start activities. If they are torn, particularly the Anterior Cruciate, then many vigorous activities will become impossible because of the instability and pain. Also, there are the medial and lateral meniscus function as shock absorber and increase the congruency between the ends of the femur and tibia. The medial meniscus is blended with fibres from the medial collateral ligaments. Therefore, any injury to the medial collateral ligament will very likely cause injury to the medial meniscus. The lateral collateral ligament has no attachments to the lateral collateral ligament. Clinically, the lateral collateral ligament constitutes only 10-20% of knee injuries whereas the medial collateral ligament constitutes 80-90%. Moreover, the weight or pressure on the medial side of the knee is normally more than the lateral side because of the structural formation. The weight bearing function is taken up by the tibia and none by the fibula. Medial knee pain is more prevalent than lateral knee pain.

The commonest cause of knee pain is a sport injury in young people involving twisting movements, especially when the foot is locked down on the ground while the upper body is still moving in space. This causes immense strain on the ligaments in the knee. The cruciate ligaments are involved if the body is moved forward and backward forcefully and the collateral ligaments are involved if the body movements cause twisting or rotatory in the knee. In all these situations, the menisci are involved to a certain degree depending on the direction of the force. However, the removal of the meniscus will inevitably cause early degeneration in the chondral bones at the ends of the femur and tibia.

In older people, knee pain is commonly caused by sprain or overuse. As the knee joint starts to degenerate, normal pressure can become abnormal. Early degeneration is the result incomplete recovery from previous injuries or insufficient rehabilitation before the subject returns to previous sport activities. In particular, the quadriceps medialis cannot function normally because of pain or loss of full extension of the knee joint. Then, atrophy of the muscle is inevitable which adds to the degenerative process. Limitation of knee flexion or bending such as squatting movements will cause early degeneration in the knee cap or patella.

It is very important for a thorough assessment of the knee before commencement of treatment. In the early stage of any sport injuries, RICE means rest, ice, compression and elevation apply. Ultrasound and interferential therapies can reduce swelling and pain. These are good adjunct therapies to manipulative therapy which directly correct mechanical faults in the knee joint.