Gluteal and Posterior Thigh Muscles Flashcards
Gluteus Medius
O: lateral surface of ilium between anterior and posterior gluteal lines
I: greater trochanter of femur
A: abduct thigh; medially rotate thigh; flex thigh (anterior fibers); laterally rotate thigh, extend thigh (posterior fibers)
Inn: superior gluteal N (L4-S1)
Gluteus Maximus
O: lateral surface of ilium behind posterior gluteal line; posterior sacroiliac and sacrotuberous ligaments; posterior surface of sacrum
I: iliotibial tract; gluteal tuberosity of femur
A: extend thigh, laterally rotate thigh (upper fibers); adduct thigh (lower fibers)
Inn: inferior gluteal N (L5-S2)
Gluteus minimus
O: lateral surface of ilium between anterior and inferior gluteal lines
I: greater trochanter of femur
A: abduct thigh, medially rotate thigh; extend thigh
Inn: superior gluteal N (L4-S1)
Piriformis
O: sacrum (anterior surface)
I: greater trochanter of femur
A: laterally rotate thigh; abduct thigh when flexed
Inn: S1 and S2
Obturator internus
O: obturator membrane; bone around obturator foramen on internal surface of pelvis
I: medial surface of grater trochanter above trochanteric fossa of femur
A: laterally rotate thigh; abduct thigh when flexed
Inn: N to obturator internus (L5-S2)
Superior gemellus
O: ischial spine
I: superior border of obturator internus tendon
A: laterally rotate thigh; abduct thigh when flexed
Inn: N to obturator internus (L5-S2)
Inferior gemellus
O: ischial tuberosity
I: inferior border of obturator internus tendon
A: laterally rotate thigh; abduct thigh when flexed
Inn: N to quadratus femoris (L4-S1)
Quadratus femoris
O: ischial tuberosity
I: posterior surface of femur between greater and lesser trochanter
A: laterally rotate thigh; adduct thigh
Inn: N to quadratus femoris (L4-S1)
Semitendinosus
O: ischial tuberosity
I: medial surface of proximal end of tibia
A: extend thigh; flex leg; medially rotate flexed leg
Inn: sciatic N, tibial part (L5-S2)
Semimembranosus
O: ischial tuberosity
I: medial condyle of tibia
A: extend thigh; flex leg; medially rotate flexed leg
Inn: sciatic N, tibial part (L5-S2)
Biceps femoris
O: long head: ischial tuberosity
Short head: linea aspera of femur and lateral inter muscular septum
I: head of fibula
A: extend thigh (long head); flex leg; laterally rotate flexed leg
Inn: sciatic N, tibial part to long head (L5-S2); common fibular part to short head (L5-S1)