The hamsting muscle actually consists of three muscles: The Biceps Femoris muscle, the Semitendinosus muscle, and the Semimembranosus muscle, these three muscles are responsible for flexion of the knee and support to the thigh. The Bicep Femoris's has an insertion at the head of the fibula. The Semitendinosus has has an insertion attachment on the upper shaft of the tibia. While a third, the semimembranosus muscle, has five insertion attachment points, the main one on the posterior portion of the medial condyle of the tibia, a second insertion point is the fascia which covers the Popliteus muscle, and the remainder insert joining the Tibial Collateral ligament of the joint and the fascia of the leg.
