The knee is one of the largest and most complex joints in the body and is subject to many forces in our everyday lives. The knee unites the thigh bone or femur to the shin bone or tibia. The smaller bone that runs alongside the tibia and fibula and the kneecap or patella comprise the other bones that make the knee joint.
Tendons connect the knee bones to the leg muscles that move the knee joint. Ligaments join the knee bones and provide stability to the knee include the anterior cruciate ligament (ACL) which prevents the femur from sliding backward on the tibia. The posterior cruciate ligament (PCL) which performs a similar function the the ACL put with counter active resistance therefore providing stability. The medial and lateral collateral ligaments prevent the femur from sliding side to side. Two C-shaped pieces of cartilage called the medial and lateral menisci act as shock absorbers between the femur and tibia. Numerous bursae, or fluid-filled sacs, help the knee move smoothly.
Knee pain commonly affects many athletes and those who exercise regularly. It is a common complaint that affects people both young and old. Knee pain may be the result of an injury, such as a ruptured ligament or torn cartilage. and can result from sports injuries or degenerative conditions. Certain medical conditions such as arthritis, gout and infections can also cause knee pain.