Function Of The Knee

The knee is one of the major weightbearing joints. It transmits the large forces generated by movements of the body. The knee must cope with walking, running, bending, jumping and lifting objects.

To perform all these activities the knee is a large joint, equipped with a large range of movement, strong ligaments and powerful muscles.

The two most important muscle groups are the quadriceps (”four heads”) and the hamstrings.

The quadriceps are the big muscle group making up the front of the thigh. The muscle starts from the thigh bone, narrows down towards the knee to the kneecap and attaches to the bump on the shin bone just below the knee called the tibial tuberosity. The quadriceps are a very powerful muscle group and straightens the knee in such activities as standing up, going up stairs or running.

The hamstrings make up the back of the thigh, coming from part of the pelvis (”the bones you sit on”) and running down the thigh to attach to the back of the fibula and tibia just below the knee. This muscle group bends the knee and straightens the hip. The hamstrings are essential to the activities of sprinting and pushing against something or someone.

These two major muscle groups control knee movement and are vital to the stability of the joint. There are other muscle groups which affect knee movement and stability but they are minor in contrast to the main groups.