What is the primary function of the ACL in the knee?

The primary function of the anterior cruciate ligament (ACL) in the knee is to stabilize the joint during rotation. The ACL plays a crucial role in preventing excessive forward movement of the tibia relative to the femur and limits rotational forces that can occur during activities such as cutting, pivoting, or twisting. This stabilization is vital for maintaining the integrity of the knee during athletic and daily activities, as it helps protect the joint from injury, particularly to the cartilage and menisci.

While shock absorption is important for overall joint function, it is primarily the role of structures like the menisci in the knee rather than the ACL. Lateral movement is generally supported by other ligaments and muscle groups, while extension of the leg is facilitated by the muscles and tendons surrounding the knee rather than being a direct function of the ACL. Thus, the stabilization provided by the ACL during rotational movements is fundamental to optimal knee function and injury prevention.