In my blog post last week I started to discuss the anatomy of the human knee. I would like to expand on this to discuss the important role played by the knee ligaments and the surrounding muscles.

Ligaments attach from bone to bone and provide the stability around a joint. They do this by adding to the proprioceptive function of the joint, when stretched they provide feedback as to what position the joint lies in. This feedback then allows the body to re-adjust its position to prevent any unwanted movement. We will focus on the four major ligaments of the knee.

The two cruciate ligaments, anterior and posterior, are often referred to as the ‘crucial’ ligaments, because of their importance in providing knee stability. The anterior cruciate ligament (ACL) prevents forward movement of the tibia in relation to the femur, and controls rotational movement of the tibia under the femur. The posterior cruciate ligament (PCL) prevents the femur from sliding forward off the top of the tibia.

As is characteristic of all hinge joints, collateral ligaments are found at the sides of the knee joint. These ligaments are called the medial and lateral collateral ligaments. All the ligaments work in concert to provide multi-directional stability around the knee.

Musculotendinous ties are also important in securing the stability of the joint. Muscles have the main job of providing dynamic stability. This is the control of movements, and because the knee supports the body weights, the control has to be extremely efficient.

There are two main muscle groups of the knee. Those that bend the knee and those that extends the knee. The hamstrings are the large muscle group at the back of the thigh which cause the knee to bend and the quadriceps are the group of muscles at the front portion of thigh that cause the knee to extend. All muscle groups have to work in unison to provide controlled movement at the joint needed for any movement/functional activity.