The Hip

Question 1

What type of joint is the hip joint?

Answer 1

Multiaxial ball and socket joint.

Question 2

What bones form the hip joint?

Answer 2

Proximal femur and the innominate bone (ilium, ischium, pubis).

Question 3

What provides hip joint stability?

Answer 3

Tough capsule, strong ligaments, deep acetabulum, and muscular support.

Question 4

How does the femoral head fit into the acetabulum?

Answer 4

Snugly, allowing both mobility and stability.

Question 5

How much body weight is loaded on the hip when standing?

Answer 5

About 2/3 of body weight.

Question 6

How much load is on the hip during walking?

Answer 6

Between 1.5–5.5 times body weight.

Question 7

How much load is on the hip when standing on one leg?

Answer 7

2–2.5x body weight.

Question 8

What is the hip load when walking upstairs?

Answer 8

~3x body weight.

Question 9

What is the load during running?

Answer 9

> 4.5x body weight.

Question 10

What is the strongest ligament of the hip?

Answer 10

Iliofemoral ligament (limits extension).

Question 11

What ligament is anterior and limits excessive abduction/extension?

Answer 11

Pubofemoral ligament.

Question 12

What is the weakest ligament of the hip?

Answer 12

Ischiofemoral ligament (posterior).

Question 13

What arteries supply the femoral head?

Answer 13

Retinacular arteries (branches of medial circumflex femoral artery).

Question 14

What can result from tearing the retinacular arteries?

Answer 14

Avascular necrosis of the femoral head.

Question 15

What does external rotation and limb shortening suggest?

Answer 15

Posterior dislocation or neck of femur fracture due to iliopsoas action.

Question 16

Iliopsoas (Iliacus + Psoas major) movement?

Answer 16

hip flexion

Question 17

Rectus femoris movement?

Answer 17

hip flexion

Question 18

Sartorius movement?

Answer 18

hip flexion, external rotation

Question 19

Pectineus movement?

Answer 19

adduction, slight flexion

Question 20

Adductors (Brevis, Longus, Magnus) movement?

Answer 20

adduction

Question 21

Gracilis movement?

Answer 21

adduction

Question 22

Obturator externus movement?

Answer 22

lateral rotation

Question 23

Tensor fascia lata movement?

Answer 23

abduction, internal rotation

Question 24

Vastus medialis/lateralis movement?

Answer 24

knee extension

Question 25

What nerve innervates gluteus maximus?

Answer 25

Inferior gluteal nerve (L5–S2).

Question 26

What is the main function of gluteus maximus?

Answer 26

Hip extension.

Question 27

Where does gluteus maximus insert?

Answer 27

Gluteal tuberosity and iliotibial tract.

Question 28

Which muscles abduct the hip?

Answer 28

Gluteus medius, gluteus minimus, tensor fascia lata.

Question 29

What nerve supplies the abductors of the hip?

Answer 29

Superior gluteal nerve (L4–S1).

Question 30

What is a Trendelenburg gait?

Answer 30

Hip drop on the contralateral side due to weak abductors or superior gluteal nerve lesion.

Question 31

Name the 6 lateral rotators of the hip.

Answer 31

Piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, quadratus femoris.

Question 32

What nerve group innervates these muscles?

Answer 32

Small branches from the sacral plexus.

Question 33

Why is the piriformis clinically important?

Answer 33

The sciatic nerve runs near or through it; tightness or variation can compress the sciatic nerve (piriformis syndrome).

Question 34

What are the posterior thigh muscles?

Answer 34

Biceps femoris, semitendinosus, semimembranosus, and hamstring part of adductor magnus.

Question 35

What nerve supplies most hamstrings?

Answer 35

Tibial nerve (sciatic nerve branch).

Question 36

What innervates the short head of biceps femoris?

Answer 36

Common fibular nerve.

Question 37

Main function of hamstrings?

Answer 37

Hip extension, knee flexion, eccentric control in running.

Question 38

Most common type of hip dislocation?

Answer 38

Posterior dislocation (e.g., dashboard injury in car accident).

Question 39

Clinical signs of posterior dislocation?

Answer 39

Adducted, internally rotated, shortened limb.

Question 40

Clinical signs of anterior dislocation?

Answer 40

Abducted, externally rotated limb.

Question 41

What spinal roots are responsible for hip flexion?

Answer 41

L2–L3

Question 42

What are the main muscles involved in hip flexion?

Answer 42

Iliopsoas, rectus femoris, sartorius, pectineus

Question 43

What nerves innervate the hip flexors?

Answer 43

Femoral nerve and lumbar plexus

Question 44

What spinal roots are responsible for hip extension?

Answer 44

L4–L5

Question 45

What are the main muscles involved in hip extension?

Answer 45

Gluteus maximus, hamstrings

Question 46

What nerves innervate the hip extensors?

Answer 46

Inferior gluteal nerve and tibial nerve

Question 47

What spinal roots are responsible for hip abduction?

Answer 47

L4–L5

Question 48

What are the main muscles involved in hip abduction?

Answer 48

Gluteus medius, gluteus minimus, tensor fascia latae

Question 49

What nerve innervates the hip abductors?

Answer 49

Superior gluteal nerve

Question 50

What spinal roots are responsible for hip adduction?

Answer 50

L2–L3

Question 51

What are the main muscles involved in hip adduction?

Answer 51

Adductor longus, adductor brevis, adductor magnus, gracilis, pectineus

Question 52

What nerve innervates the hip adductors?

Answer 52

Obturator nerve (Note: part of adductor magnus = sciatic nerve, pectineus = femoral nerve)