Week 8 - The Gluteal Region (inc. Trendelenburg test)

Question 1

What are the actions of gluteus maximus?

Answer 1

Main extensor at the hip
Assists in lateral rotation
However:
Only acts when some degree of force is required in these motions, e.g. cycling

Question 2

What nerve innervates the gluteus maximus?

Answer 2

The inferior gluteal nerve

Take care! Maximus does not mean superior!

Question 3

What are the actions of gluteus medius and gluteus minimus?

Answer 3

Abduction
Medial rotation
Prevent pelvis dropping when the foot is lifted off the floor

Question 4

What other muscle has the same actions as gluteus medius and gluteus minimus?

Answer 4

Tensor of fascia lata

Question 5

What nerve innervates gluteus medius, gluteus minimus and tensor of fascia lata?

Answer 5

The superior gluteal nerve

Question 6

Which muscles make up the deep compartment of the gluteal region?

Answer 6

Piriformis
Gemelli x2
Obturator internus
Quadratus femoris

Question 7

What are the actions of piriformis? Which other muscles have these (and only these) actions?

Answer 7

Abduction and lateral rotation

Obturator internus
The Gemellis

Question 8

What is the action of quadratus femoris?

Answer 8

Lateral rotation of the hip

Question 9

Which nerve innervates the piriformis?

Answer 9

Nerve to piriformis

Question 10

Which nerve innervates the Gemellis?

Answer 10

Superior gemelli - nerve to obturator internus

Inferior gemelli - nerve to quadratus femoris

Question 11

Which nerve innervates obturator internus?

Answer 11

Nerve to obturator internus

Question 12

What nerve innervates quadratus femoris?

Answer 12

Nerve to quadratus femoris

Question 13

Where is the gluteal region found?

Answer 13

Posterior to the pelvic girdle, at the proximal end of the femur

Question 14

What are the general actions of the superficial compartment of the gluteal region?

Answer 14

Abduct and extend the leg at the hip

Question 15

What is the general action of the deep compartment of the gluteal region?

Answer 15

Lateral rotation

All but quadratus femoris also abduct

Question 16

Which muscles make up the superficial compartment of the gluteal region?

Answer 16

Gluteus maximus
Gluteus medius
Gluteus minimus

Question 17

Explain the pathophysiology behind a positive left Trendelenburg test.

Answer 17

When right leg lifted off floor, left gluteus medius and gluteus minimus should support pelvis on the right side. However, if the superior gluteal nerve is lesioned, these muscles are paralysed. Causes iliac crest to drop on right hand side, but as muscles are on left, it is positive on left.

Question 18

Which muscles are paralysed if a Trendelenburg test is positive?

Answer 18

Gluteus medius and gluteus minimus

Question 19

Why would gluteus medius and gluteus minumus be paralysed, as in a positive Trendelenburg test?

Answer 19

Lesion to the superior gluteal nerve

Question 20

What does the Trendelenburg test look for?

Answer 20

Lesions of the superior gluteal nerve, resulting in glut med and min paralysis and hence pelvic drop