[Muscles]

Question 1

piriformis

Answer 1

O: anterior surface of sacrum
Ins: medial side and superior border of greater trochanter
Inn: branches from S1 and S2
Bs: superior gluteal artery
Action: laterally rotates extended femur and abducts flexed femur

Question 2

quadratus internus

Answer 2

O: deep surface of obturator membrane and surrounding bone
Ins: medial side of greater trochanter
Inn: nerve to quadratus internus
Bs: inferior gluteal A
Action: laterally rotates extended femur and abducts flexed femur

Question 3

gamellus superior

Answer 3

O: external surface of ischial spine
Ins: superior surface on quadratus internus tendon and into medial side of greater trochanter
Inn: nerve to obturator internus
Bs: inferior gluteal A
Action: laterally rotates extended femur and abducts flexed femur

Question 4

gamellus inferior

Answer 4

O: upper aspect of ischial tuberosity
Ins: inferior surface on quadratus internus tendon and into medial side of greater trochanter
Inn: nerve to quadratus femoris
Bs: inferior gluteal A
Action: laterally rotates extended femur and abducts flex femur

Question 5

quadratus femoris

Answer 5

O: lateral surface of ischium just anterior to ischial tuberosity
Ins: quadrate tubercle of interotrochanteric crest of proximal femur
Inn: nerve to quadratus
Bs: inferior gluteal A
Action: laterally rotates thigh at hip joint