Which muscle is mainly responsible for knee flexion?

The hamstrings are primarily responsible for knee flexion. This group of muscles, located at the back of the thigh, consists of the biceps femoris, semitendinosus, and semimembranosus. Their primary function is to flex the knee while also assisting with hip extension.

In typical movement patterns, when the knee is bent, such as during walking or running, the hamstrings contract to enable the leg to move backward. They play a critical role in various activities, particularly those involving bending at the knee joint.

Understanding the function of the hamstrings in knee flexion helps clarify their significance in both athletic performance and rehabilitation contexts, emphasizing their importance in activities that require the bending of the knee.