GROSS ANATOMY

Detailed explanation-1: -Hamstrings. The semitendinosus, semimembranosus, and biceps femoris (long and short heads) make up the hamstring group. Spanning the posterior thigh, the hamstring muscles are the primary knee flexors. The hamstrings also perform hip extension, excepting the short head biceps femoris.

Detailed explanation-2: -The hamstring muscle group plays a prominent role in hip extension and knee flexion. The semitendinosus, semimembranosus, and biceps femoris muscles comprise the hamstring muscle group.

Detailed explanation-3: -At the knee joint, flexion and extension are the main movements, which are caused by the quadriceps group of muscles. This group consists of four muscles – rectus femoris, vastus medialis, vastus intermedius and vastus lateralis – and is located on the anterior thigh.

Detailed explanation-4: -The one muscle that extends the knee is the massive quadriceps. We saw it briefly in the last section. We’ll take a better look at it now. The main flexors of the knee are the so-called hamstring muscles, semi-membranosus, semitendinosus, and biceps femoris.

Detailed explanation-5: -Contraction of the hamstring muscles can produce both knee flexion, and hip extension. When knee flexion is held in check by the action of quadriceps, the hamstrings just produce extension at the hip, which is the action that propels us forward in normal walking.