What movement(s) does the hamstrings muscle group perform?

The hamstrings muscle group is primarily responsible for two key movements: knee flexion and hip extension. The hamstrings consist of three muscles: the biceps femoris, semitendinosus, and semimembranosus. When these muscles contract, they pull on the bones of the leg, allowing the knee joint to bend, which is what constitutes knee flexion.

Concurrently, as the hamstrings work, they also play an important role in extending the hip joint. This means that when the hip is extended—such as when a person moves their thigh backward—the hamstrings are actively engaged in that movement.

Understanding the primary actions of the hamstrings is crucial for developing effective training programs, addressing athletic performance, and evaluating and rehabilitating injuries related to the posterior chain. Recognizing that the hamstrings do not perform knee extension or hip flexion helps clarify their functions and allows for a better foundation in human movement science. This knowledge is vital for kinesiologists and fitness professionals guiding clients through exercises that target these muscle groups.