Back Legs

Question 1

Adductor Longus

Answer 1

Innervation: obturator nerve Origin: anterior surface of pubis, inferior to the pubic tubercle Insertion: middle 1/3 of linea aspera of the femur Action: adduction, flexion, and medial rotation of thigh

Question 2

Adductor Brevis

Answer 2

Innervation: obturator nerve Origin: inferior ramus of the pubis Insertion: superior 1/3 of linea aspera of the femur Action: adduction, flexion, and medial rotation of thigh

Question 3

Adductor Magnus

Answer 3

Innervation: obturator nerve, sciatic nerve (tibial portion) Origin: inferior ramus of the pubis and ischium and the ischial tuberosity Insertion: linea aspera, medial supracondylar ridge, and adductor tubercle of femur Action: adduction of the thigh; anterior fibers from the inferior ramus of the pubis also flex and medially rotate the thigh; posterior fibers from the ramus of the ischium and the ischial tuberosity extend and laterally rotate the thigh

Question 4

Gracilis

Answer 4

Innervation: obturator nerve Origin: pubic symphysis and arch Insertion: proximal, medial tibial shaft just inferior to the medial tibial condyle Action: adduction and medial rotation of the thigh; flexion and medial rotation of the leg

Question 5

Semitendinosus

Answer 5

Innervation: sciatic nerve (tibial portion) Origin: ischial tuberosity (common tendinous origin with the long head of the biceps) Insertion: proximal, medial tibial shaft just inferior to the medial tibial condyle Action: extension of the thigh with some adduction and medial rotation; flexion and medial rotation of the leg

Question 6

Semimembranosus

Answer 6

Innervation: sciatic nerve (tibial portion) Origin: ischial tuberosity Insertion: postero-medial aspect of the medial tibial condyle Action: extension of the thigh with some adduction and medial rotation; flexion and medial rotation of the leg

Question 7

Biceps Femoris

Answer 7

Innervation: Long head: sciatic nerve (tibial portion) Short head: sciatic nerve (common peroneal portion) Origin: Long head: ischial tuberosity Short head: middle 1/3 of the linea aspera of the femur Insertion: Both heads: head of fibula and lateral condyle of the tibia Action: Long head: extension with some lateral rotation of the thigh Both heads: flexion and lateral rotation of the leg

Question 8

Pectineus

Answer 8

Innervation: femoral nerve Origin: superior ramus of pubis Insertion: pectineal line of femur Action: adduction, flexion, and medial rotation of thigh