2. The gluteal region

Question 1

name the 4 superficial muscles of the gluteal region and state their innervation

Answer 1

1. gluteus maximus (inferior gluteal n.)
2. gluteus medius (superior gluteal n.)
3. gluteus minimus (superior gluteal n.)
4. tensor fascia lata (superior gluteal n.)

Question 2

what is main function of gluteus maximus

Answer 2

hip extension (important in running and when rising from sitting)

Question 3

what are functions of gluteus medius and minimus

Answer 3

• hip abduction and medial rotation

- stabilise pelvis during locomotion

Question 4

attachments of gluteus maximus are?

Answer 4

• origin: gluteal surface of ilium and sacrum

- insertion: iliotibial tract and gluteal tuberosity of femur

Question 5

attachments of gluteus medius and minimus are?

Answer 5

• origin: gluteal surface of ilium

- insertion: greater trochanter of femur

Question 6

name the 5 muscles located deep to gluteus minimus

Answer 6

1. piriformis
2. gemellus superior
3. obturator internus
4. gemellus inferior
5. quadratus femoris

Question 7

which structure passes directly deep to piriformis

Answer 7

sciatic n.

Question 8

which muscles are affected by damage to the superior gluteal n.

Answer 8

paralysis of gluteus medius and minimus

Question 9

which sign indicates damage to the superior gluteal n.

Answer 9

+ve trendelenberg sign: pelvic drop of unsupported leg indicates paralysis of contralateral muscles (as cannot contract to stabilise pelvis)

Question 10

why must a safe site be used for intramuscular injections into the buttock

Answer 10

avoid injury to sciatic n. and other neurovascular structures (eg gluteal nerves) in medial and inferior parts of gluteal region

Question 11

describe the 2 safe sites used for intramuscular injections into the buttock

Answer 11

1. dorsogluteal region: upper outer quadrant of buttock (children >3yo)
2. ventrogluteal region: place palm of hand over greater trochanter of femur, point thumb towards inguinal region and index towards anterior superior iliac crest. Spread index and middle finger to make a V and inject between PIPJ of fingers into gluteus medius.