Muscles of posterior compartment of thigh

Question 1

Bicepts femoris

Answer 1

Origin:

• Long head - Inferomedial part of the upper area of the ischial tuberosity
• Short head - lateral lip of line aspera

Insertion:

• Head of fibula

Innervation:

• Sciatic nerve (L5, S1, S2)

Function:

• Flexes leg at knee joint, extends and laterally rotates thigh at hip joint and laterally rotates leg at knee joint

Question 2

Semitendinous

Answer 2

Origin:

• Inferomedial part of the upper area of the ischial tuberosity

Insertion:

• Medial surface of proximal tibia

Innervation

• Sciatic nerve (L5, S1, S2)

Function:

• Flexes leg at knee joint and extends thigh at hip joint, medially rotates thigh at hip joint and leg at knee joint

Question 3

Semiembranous

Answer 3

Origin:

• Superolateral impression on the ischial tuberosity

Insertion:

• Groove and adjacent bone on medial and posterior surface of medial tibial condyle

Innervation:

• Sciatic nerve (L5, S1, S2)

Function:

• Flexes leg at knee joint and extends thigh at hip joint, medially rotates thigh at hip joint and leg at knee joint