Which ligament prevents excessive forward movement of the tibia?

The anterior cruciate ligament (ACL) plays a crucial role in stabilizing the knee joint by preventing excessive forward movement of the tibia relative to the femur. When the knee is in flexion, the ACL tightens to resist anterior displacement of the tibia, which helps maintain proper alignment and function of the knee during activities like running, jumping, and pivoting. This is essential for preventing injuries, as excessive forward movement can lead to joint instability and damage to surrounding structures.

The other ligaments mentioned, such as the collateral ligaments and the posterior cruciate ligament (PCL), serve different functions. The collateral ligaments provide stability against lateral forces, while the PCL functions to prevent backward movement of the tibia and contributes to overall knee stability. The medial ligament, also known as the medial collateral ligament, primarily helps resist valgus forces but does not directly control the forward movement of the tibia. Thus, the primary responsibility for preventing excessive anterior displacement lies with the ACL.