Biceps Femoris

Origin: Long head originates from the ischial tuberosity of the pelvis. Short head originates from the linea aspera of the femur.

Insertion: The long head inserts into the head of the fibula, and the short head inserts into the lateral condyle of the tibia.

Action: The biceps femoris is involved in both knee flexion and hip extension. It plays a crucial role in activities such as running and bending the knee.

Semitendinosus

Origin: Ischial tuberosity of the pelvis.

Insertion: Proximal part of the medial surface of the tibia (shinbone).

Action: The semitendinosus is responsible for knee flexion and hip extension. It also helps stabilize the knee joint.

Semimembranosus

Origin: Ischial tuberosity of the pelvis.

Insertion: Posterior surface of the medial condyle of the tibia.

Action: The semimembranosus is primarily involved in knee flexion and hip extension. It also provides stability to the knee joint.