LM 6.2: Gluteal Region

Question 1

What is the function of the cluneal nerves?

Answer 1

The sensory nerves of the gluteal region

They carry sensory afferent fibers from the skin of the gluteal region

Question 2

What are the borders of the gluteal region?

Answer 2

Iliac crest to gluteal fold (bottom of your butt)

Laterally it extends from the mid axillary line

Question 3

If there is left hip drop every time a patient lifts his left foot off the floor but on the right side his pelvis remains level when he lifts up his right foot. Which nerve has been effected? What happens when this nerve is injured?

Answer 3

The superior gluteal nerve

The right side remains level because the muscles on the left side are intact! These muscles include the abductors of the left lower limb which keep the pelvis level

His left hip drops because the muscles on the gluteal region on the right side are weak and can’t abduct — injury has occurred at gluteus medius muscle due to injury of the superior gluteal nerve that innervates it so the gluteus medius muscle can’t support the hip and it drops

The patient can’t lift left lower limb due to weakened abduction of the contralateral gluteals medius, gluteus minimus and tensor fascia lata so the pelvis can’t stay horizontal

Question 4

Which muscles are innervated by the superior gluteal nerve? What is their action?

Answer 4

1. Gluteus medius
2. Gluteus minimus
3. Tensor of the fascia lata

They all abduct and medially rotate the hip

Question 5

What is the fascia lata?

Answer 5

The deep fascia of the thigh between the knee and the hip

Question 6

What is the cru fascia?

Answer 6

The deep fascia of the leg between the knee and the ankle

Question 7

What is a positive Trendelemburg sign?

Answer 7

Dropping of the pelvis when the patient is asked to stand on one foot/lifts their foot while walking

Question 8

What are the nerves of the gluteal region?

Answer 8

1. Superior gluteal nerve
2. Inferior gluteal nerve
3. Pudendal nerve
4. Sciatic nerve
5. Posterior cutaneous nerve of the thigh

Question 9

Which nerve innervates the gluteus maximus?

Answer 9

Inferior gluteal nerve

Question 10

Which muscles does the pudendal nerve innervate?

Answer 10

Peritoneum and external genitalia

Question 11

Which muscles are involved in lateral rotation of the hip?

Answer 11

1. Piriformis
2. Superior gemellus
3. Inferior gemellus
4. Obturator internus
5. Quadratus femoris

Question 12

what is the piriformis used as a landmark for?

Answer 12

the superior gluteal nerve runs superior to it while the inferior gluteal nerve runs inferior to it

actually all the other nerves except the superior gluteal nerve

Question 13

what is the attachment, action and innervation of the gluteus maximus?

Answer 13

distal attachment to the most lateral condyle of the tibia via the iliotibial tract

action = hip extension

innervation = inferior gluteal nerve

Question 14

what is the attachment, action and innervation of the gluteus medius?

Answer 14

proximal attachment = external surface of allium superior to gluteus minimus

distal attachment = greater trochanter of femur

action = abduction and medial rotation of hip

innervation = superior gluteal nerve

Question 15

what is the attachment, action and innervation of the gluteus minimus?

Answer 15

proximal attachment = external surface of ilium inferior to gluteus medius

distal attachment = greater trochanter of femur

action = abduction and medial rotation of the thigh

innervation = superior gluteal nerve

Question 16

what is the attachment, action and innervation of the tensor fascia lata?

Answer 16

proximal attachment = anterior superior iliac crest (ASIS)

distal attachment = lateral condyle of tibia via IT tract

action = abduction and medial rotation of rhigh

innervation = superior gluteal nerve

Question 17

what is the attachment, action and innervation of the piriformis?

Answer 17

proximal attachment: anterior surface of sacrum

distal attachment: greater trochanter of femur

action: laterally rotates thigh

Question 18

where does the piriformis travel through?

Answer 18

the greater sciatic foramen

Question 19

what is the attachment and action of the superior and inferior gemelli muscles?

Answer 19

they’re located superior and inferior to the tendon of the obturator internus muscle

distal attachment = near greater trochanter of femur

action = laterally rotate thigh

Question 20

what is the attachment and action of the operator internus?

Answer 20

proximal attachment = Internal surface of obturator membrane

distal attachment = near greater trochanter of femur

makes a 90˚ turn on the lesser sciatic notch

action = laterally rotates thigh

Question 21

what is the action of the quadratus femoris?

Answer 21

lateral rotate hip

Question 22

where are the superior and inferior gluteal arteries located?

Answer 22

the superior gluteal artery exits the pelvis through the greater sciatic foramen superior to the piriformis muscle

the inferior gluteal artery exits the pelvis through the greater sciatic foramen inferior to the piriformis muscle