Innervation and Actions of Hip and Pelvis

Question 1

Psoas Maj

Answer 1

Innerve.: Lumbar plexus
(L1 - L4)

Act.: Flexion at hip joint and if thigh fixed flexes trunk

Question 2

psoas min

Answer 2

Innerve.: branch from L1

Act.: weak flexor of the trunk
(Note-does not cross hip so no action there)

Question 3

quadratus lumborum

Answer 3

Innerve.: Lumbar plexus
(L1 - L4)

Act.: Lateral flexion of
vertebral column,
extension of vertebral
column, stabilizes 12th
rib during inspiration,
depresses 12th rib
during forced expiration,
and elevate coxal bone

Question 4

iliacus

Answer 4

Innerve.: Femoral N
(L2 - L4)

Act.: Flexion at hip joint

Question 5

glute max

Answer 5

Innerve.: Inferior gluteal n
(L5 - S2)

Act.: Extends hip against
resistance, assists in
external rotation at hip
joint and helps stabilizes
knee joint in extension
via iliotibial tract
& extends trunk when
hip is flexed
(assists abduction of hip)

Question 6

glute med

Answer 6

Innerve.: Superior gluteal n
(L4 - S1)

Act.: Abduction the hip
Anterior: Internal rotation
and may assist with flexion
at hip joint
Posterior: External rotation
and may assist with extension
at the hip joint

Question 7

glute min

Answer 7

Innerve.: Superior gluteal n
(L4 - S1)

Act.: Internal rotation and
assists abduction at hip
joint

Question 8

tensor fasciae latae (TFL)

Answer 8

Innerve.: Superior gluteal n
(L4 - S1)

Act.: Assist flexion, abduction,
medial rotation at hip jt.,
and assist in stabilizing
knee in extension

Question 9

piriformis

Answer 9

Innerve.: Nerve to piriformis
(S1- S2)

Act.: External rotation at
hip and assits in abduction
of hip when flexed to 90
degrees (or greater)

Question 10

superior gemellus

Answer 10

Innerve.: Nerve to obturator
internus and
superior gemellus
(L5 - S2)

Act.: External rotation at hip joint

Question 11

obturator internus

Answer 11

Innerve.: Nerve to obturator internus and superior gemellus
(L5 - S2)

Act.: External rotation at hip joint

Question 12

inferior gemellus

Answer 12

Innerve.: Nerve to quadratus femoris and inferior gemellus
(L4 - S1)

Act.: External rotation at hip joint

Question 13

quadratus femoris

Answer 13

Innerve.: Nerve to quadratus femoris and
inferior gemellus
(L4 - S1)

Act.: External rotation at hip joint

Question 14

obturator externus

Answer 14

Innerve.: Obturator nerve
(L2 - L4))

Act.: External rotation at hip joint