anterior cruciate ligaments

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The main ligaments in the knee binding the back of the thigh bone (the femur) to the front of the shin bone (the tibia). They stop the shin bone from moving excessively forward in relation to the femur. If they are damaged, the knee becomes unstable and wobbles.

Injuries to the cruciate ligament can be dramatic, incapacitating a person instantly. Falling backwards at high speed is a common cause of such injuries among skiers, especially those who are poorly conditioned. Surgery is sometimes needed to rebind the bones.

Rehabilitation includes special exercises. A typical programme starts immediately after the operation with slow flexion on a passive motion machine. This is followed by several weeks of active bending and straightening of the knee. During this time, more strenuous activities, such as cycling on a stationary bike and exercising in water, are gradually introduced.