Muscles of the Posterior Thigh

Question 1

Semitendinosus

Answer 1

O: ischial tuberosity

I: medial surface of superior part of the tibia

A: Extension of thigh, flexion of leg, medially rotate leg; when thigh and leg fixed can extend trunk

N: tibial division of sciatic n. L5-S2

Question 2

Semimembranosus

Answer 2

O: ischial tuberosity

I: post. part of medial condyle of tibia; oblique popliteal ligament

A: extends thigh; flexes and medially rotates leg; when thigh fixed can extend trunk

N: Tibial division of sciatic n. L5-S2

Question 3

Biceps Femoris Long Head

Answer 3

O: ischial tuberosity

I: lat. side of head of fibular; tendon is split by lateral collateral ligament

A: flexes and lat. rotates leg; extends thigh at beginning of walking

N: tibial division of sciatic n. L5-S2

Question 4

Biceps Femoris Short Head

Answer 4

O; lateral lip of linea aspera and lat. supracondylar line

I: lat. side of head of fibula; tendon is split by lat. collateral ligament

A: flexes and lat. rotates leg; extends thigh at beginning of walking

N: common peroneal division of sciatic n. L5-S2