Lower Limb Muscles and Innervations

Question 1

Gluteal Muscles (and innervation)

Answer 1

Gluteus Maximus - thigh extensor at hip (inferior gluteal nerve)
Gluteus Medius - thigh abductor at hip (superior gluteal nerve)
Gluteus Minimus - “

Question 2

Thigh Extensors at the Hip (and innervation)

Answer 2

Long Head of Biceps Femoris - Tibial nerve
Semitendinosus - “
Semimembrinosus - “

Question 3

Lateral Thigh Rotators at Hip (and innervation)

Answer 3

Piriformis - Ventral Rami (L5-S2)
Gemellus Superior - Obturator Internus Nerve
Obturator Internus - Obturator Internus Nerve
Gemellus Inferior - “
Quadratus Femoris - “

Question 4

Short Head of Biceps Femoris (action and innervation)

Answer 4

Extends the thigh + Flexes the leg

Common Fibular Nerve

Question 5

Superior Muscles of Posterior Leg (action and innervation)

Answer 5

Gastrocnemius - Plantar Flexion of the foot, Tibial Nerve
Soleus - “
Plantaris - “

Question 6

Deep Muscles of the Posterior Leg (action and innervation)

Answer 6

Popliteus - unlocks the knee
Flexor Hallicus Longus - flexes “curls” big toe
Tibial Posterior - inversion and plantar flexion of foot
Flexor Digitorum Longus - flexes lateral 4 digits of foot
All innervated by Tibial nerve

Question 7

Thigh Flexors at the Hip (and innervation)

Answer 7

Rectus Femoris
Vastus Lateralis
Vastus Intermedius
Vastus Medialis
Sartorial - also laterally rotates and abducts thigh at hip
*All innervated by Femoral Nerve*

Question 8

Pectineus muscle (location, action and innervation)

Answer 8

Location: floor of the femoral triangle
Adducts and flexes the thigh
Innervated by Femoral nerve and Obturator Nerve

Question 9

Thigh Adductors at the Hip (innervation)

Answer 9

Gracilis - adducts + flexes the thigh
Adductor Longus - adducts
Adductor Brevis - “
Adductor Magnus - “
*All innervated by the Obturator Nerve*

Question 10

Obturator Externus (action and innervation)

Answer 10

Laterally rotates the thigh

Innervated by Obturator nerve

Question 11

Illiopsoas (action and innervation)

Answer 11

Flexion and lateral rotation of thigh at the hip

Innervated by Femoral nerve

Question 12

What is the function of the Popliteus muscle?

Answer 12

To unlock the knee

Question 13

A gluteal intramuscular injection would best be placed at the…

Answer 13

Upper lateral quadrant of the gluteal region, so as to avoid directly damaging the Sciatic nerve (L4-S3)

Question 14

A positive result of the Anterior Drawer’s Sign indicates damage to what ligament?

Answer 14

Anterior Cruciate ligament (ACL) - normally prevents hyperextension of the knee joint. Damage to the ACL allows the tibia to move anteriorly to the femur, like pulling out a drawer.

Question 15

Damage to the Common Fibular Nerve causes what abnormality during the gait cycle?

Answer 15

Foot Drop = common from lateral valgus stress injury such as splicing someone’s knees in football.

Question 16

What muscle of the lower limb flexes the leg at the knee joint and plantar flexes the ankle?

Answer 16

Gastrocnemius

Question 17

What muscle causes dorsiflexion at the ankle and inverts the foot?
What is it innervated by?

Answer 17

Tibialis Anterior;

Deep Fibular Nerve

Question 18

What nerve provides cutaneous sensation to the web space between the 1st and 2nd toe?

Answer 18

Deep Fibular Nerve

Question 19

In regards to blood supply, the ________ artery supplies the medial thigh. The deep femoral artery supplies the _________ thigh. The gluteal region is supplied by the ________/______ ______ arteries.

Answer 19

Obturator artery = medial thigh;
Deep Femoral artery = posterior thigh;
Superior/Inferior Gluteal arteries = gluteal region

Question 20

What nerve supplies cutaneous sensation to the medial side of the leg and ankle?

Answer 20

Saphenous nerve

Question 21

A lesion of the S1 ventral root would present as a loss in what reflex?

Answer 21

Achilles’ tendon Reflex is tested when the calcaneous tendon is knocked leading to plantar flexion at the foot from muscles innervated by Tibial nerve.