Anatomy - Hip And Thigh

Question 1

Describe gluteus maximus.

Answer 1

Origin: outer surface of ala, thoraco lumbar aponeurosis, posterior surface of sacrum, sacrotuberal ligament.
Insertion: iliotibial tract, femur-gluteal tuberosity
Innervation: inferior gluteal nerve
Movement: extension, assists with lateral rotation

Question 2

Describe gluteus medius.

Answer 2

Origin: gluteal surface of the ilium.
Insertion: lateral surface of greater trochanter.
Innervation: Superior gluteal nerve.
Movements: abducts and medially rotates lower limb

Question 3

Describe piriformis.

Answer 3

Origin: sacrum, pelvic surface
Insertion: greater trochanter
Innervation: nerve to piriformis
Movements: lateral rotation and abduction

Question 4

Describe obturator internus.

Answer 4

Origin: obturatory membrane
Insertion: trochanteric fossa
Innervation: nerve to obturator internus
Movements: lateral rotation and abduction

Question 5

Describe biceps femoris.

Answer 5

Origin: long head - ischial tuberosity; short head - linea aspera on posterior surface of femur
Insertion: head of fibula
Innervation: long head - tibial part of sciatic nerve; short head - common fibular part of sciatic nerve
Movements: extension of thigh at the hip, flexion of the knee, lateral rotation at hip and knee

Question 6

Describe semitendinosis

Answer 6

Origin: ischial tuberosity
Insertion: pes anserinus (medial surface of tibia?)
Innervation: tibial part of sciatic nerve
Movements: extension of thigh at hip, flexion of leg at knee, medial rotation of thigh and leg

Question 7

Describe semimembranosus

Answer 7

Origin: ischial tuberosity
Insertion: medial condyle of tibia
Innervation: tibial part of sciatic nerve
Movements: extension of thigh at hip, flexion of leg at knee, medial rotation of thigh and leg

Question 8

What are the nerve roots of the sciatic nerve?

Answer 8

L4 - S3

Question 9

What are the motor innervations of the sciatic nerve?

Answer 9

• biceps femoris, semitendinosis, semimembranosus
• hamstring portion of adductor magnus
• indirectly innervates (via terminal branches) all muscles of leg and foot

Question 10

What are the sensory innervations of the sciatic nerve?

Answer 10

• no direct sensory functions

- indirectly innervates (via terminal branches) the skin of lateral leg, heel, dorsal and plantar surface of foot