Medial (Internal) Rotators of the Knee

Question 1

Semimembranosus

Answer 1

O: ischial tuberosity of the innominate bone
I: posteromedial surface of medial condyle of tibia
N: Sciatic nerve L5, S1, S2
A: Extension of the hip & flexion of the knee joint

Question 2

Semitendinosus

Answer 2

O: ischial tuberosity of the innominate bone
I: medial surface of medial condyle of tibia
N: Femoral nerve L2, L3
A: extension of the hip & flexion of the knee joint

Question 3

Sartorius

Answer 3

O: anterior superior iliac spine (ASIS) of the innominate bone
I: medial side of the body of the tibia
N: femoral nerve L2, L3
A: flexion of hip & knee; lateral rotation and abduction of the thigh; medial rotation of the tibia on the femur

Question 4

Gracilis

Answer 4

O: front of the body of the pubis, inferior pubic and ischial rami of the innominate bone
I: medial surface of the body of the tibia
N: Obturator nerve L2, L3
A: adduction of the thigh and flexion of the knee joint

Question 5

Popliteus

Answer 5

O: anterior aspect of the outer surface of the lateral condyle of the femur
I: posterior surface of the tibia above the soleal line
N: Tibial nerve L5
A: Lateral rotation of the femur on the tibia, unlocking the knee from the close-packed position