Posterior Thigh

Question 1

Biceps femoris

Answer 1

Origin:
* Long head: Ischial tuberosity
* Short head: Linea aspera, lateral supracondylar line

Insertion: Head of fibula
Action: Knee flexion, external rotatation. Hip extension (long head only)
Innervation:
* Long head: Tibial division of sciatic n.
* Short head: Common fibular division of sciatic n.

Question 2

Semitendinosus

Answer 2

Origin: Ischial tuberosity
Insertion: Medial aspect of proximal tibia
Action: Knee flexion, internal rotation. Hip extension
Innervation: Tibial division of sciatic n.

Question 3

Semimembranosus

Answer 3

Origin: Ischial tuberosity
Insertion: Medial condyle of tibia
Action: Knee flexion, internal rotation. Hip extension
Innervation: Tibial division of sciatic n.