The lateral Collateral Ligament or LCL is on the outside of the knee and joins the outer surface of the femur to the head of the fibula. It resists impacts from the inner surface of the knee known as varus forces.
The knee joint is the largest joint in the body, consisting of 4 bones and an extensive network of ligaments and muscles.
The patella lies in an indentation at the lower end of the femur known as the intercondylar groove.
At the outer surface of the tibia is the fibula, a long thin bone that travels right down to the ankle joint. The function of the tibia is predominantly load bearing whilst the function of the fibula is predominantly to provide a surface for muscles to attach to.
The quadriceps muscle group is made up of four different individual muscles which join together forming the quadriceps tendon. This thick tendon connects the muscle to the patella which in turn connects to the tibia via the patella tendon. Contraction of the quadriceps pulls the patella upwards and extends the knee. The quadriceps muscles consist of the biceps femoris, vastus medialis, vastus intermedius and vastus lateralis muscles.
The anterior Cruciate Ligament or ACLis one of the most important structures in the knee, not least because injury to it may require extensive surgery and rehabilitation. The cruciate ligaments are so called because they form a cross in the middle of the knee joint. The ACL, travels from the anterior or front of the tibia to the posterior or back of the femur and prevents the tibia moving forward. It is most commonly injured in twisting movements.
Each are covered in articular cartilage which is an extremely hard, smooth substance designed to decrease the frictional forces as movement occurs between the bones.
The two main muscle groups of the knee knee joint are the quadriceps and the hamstrings. Both play a vital role, both moving and stabilizing the knee joint.
The medial Collateral Ligament or MCL for sort is a band that runs between the inner surfaces of the femur and the tibia. It resists forces acting from the outer surface of the knee called valgus forces and prevents the knee from collapsing inwards. The medial knee ligament has two parts to it; an inner part which attaches to the cartilage meniscus on the inside of the knee and an outer part with attaches to the tibia bone.