Hamstring Strains are one of the most common sports injuries. The hamstring muscles are found at the back of your thigh. The hamstrings are composed of three main muscles; the biceps femoris muscle, the semimembranosus muscle and the semitendinosus muscle. The biceps femoris muscle is the most commonly injured. Hamstring strains occur when excessive or sudden tension is put through the hamstring muscle fibres. Hamstring strains vary from simple strains to complete tears. The