Lateral rotator group

Question 1

piriformis origin

Answer 1

• anterior surface of 2nd to 4th sacral segments

- superior margin of greater sciatic notch and sacrotuberous ligament

Question 2

piriformis insertion

Answer 2

superior border of greater trochanter of femur

Question 3

piriformis innervation

Answer 3

nerve to piriformis

Question 4

piriformis blood supply

Answer 4

superior and inferior gluteal arteries

Question 5

piriformis action

Answer 5

• laterally rotate extended thigh and abduct flexed thigh; steady femoral head in acetabulum

Question 6

gemellus superior origin

Answer 6

Ischial spine

Question 7

gemellus superior insertion

Answer 7

medial surface of greater trochanter of femur

Question 8

gemellus superior nerve

Answer 8

nerve to orbturator internus

Question 9

gemellus superior blood supply

Answer 9

inferior gluteal artery

Question 10

gemellus superior action

Answer 10

• laterally rotate extended thigh and abduct flexed thigh

- steady femoral head in acetabulum

Question 11

obturator internus origin

Answer 11

pelvic surface of ilium and ischium, obturator membrane

Question 12

obturator internus insertion

Answer 12

medial surface of greater trochantor of femur

Question 13

obturator internus nerve

Answer 13

nerve to obturator internus

Question 14

obturator internus action

Answer 14

• laterally rotate extended thigh, and abduct flexed thigh

- steady femoral head in acetabulum

Question 15

obturator internus blood supply

Answer 15

inferior gluteal artery

Question 16

gemellus inferior origin

Answer 16

ischial tuberosity

Question 17

gemellus inferior insertion

Answer 17

medial surface of greater trochanter of femur

Question 18

gemellus inferior nerve

Answer 18

nerve to quadratus femoris

Question 19

gemellus inferior action

Answer 19

• laterally rotate extended thigh, and abduct flexed thigh

- steady femoral head in acetabulum

Question 20

gemellus inferior blood supply

Answer 20

inferior gluteal artery

Question 21

obturator externus origin

Answer 21

margins of the obturator foramen and obturator membrane

Question 22

obturator externus insertion

Answer 22

trochanteric fossa of femur

Question 23

obturator externus nerve

Answer 23

obturator nerve

Question 24

obturator externus action

Answer 24

laterally rotates thigh

steadies head of femur in acetabulum

Question 25

obturator externus blood supply

Answer 25

obturator artery

Question 26

quadratus femoris origin

Answer 26

lateral border of ischial tuberosity

Question 27

quadratus femoris insertion

Answer 27

quadrate tubercle on intertrochanteric crest of femur

Question 28

quadratus femoris nerve

Answer 28

nerve to quadratus femoris

Question 29

quadratus femoris action

Answer 29

laterally rotates thigh and steadies head of femur in acetabulum

Question 30

quadratus femoris bs

Answer 30

inferior gluteal artery