Lower Limb - Intrinsic Muscles Foot

Question 1

Which nerve(s) innervated the Intrinsic muscles of the foot (excluding extensor digitorum brevis and medial 2 dorsal interossei)?

Answer 1

Medial and lateral plantar branches of tibial nerve

EDB and medial 2 dorsal interossei innervated by deep fibular nerve

Question 2

Which muscle(s) extend the medial 4 MTP joints?

Answer 2

Extensor Digitorum Brevis

Question 3

The intrinsic muscles of the plantar aspect of the foot are made up of 4 layers.

1.1. Name the muscles within each layer

Answer 3

1.1.

1st layer (most superficial): Flexor Digitorum Brevis, Abductor Hallucis, Abductor Digiti Minimi

2nd layer: Quadratus Plantae, 4 lumbricals

3rd layer: Flexor Digiti Minimi Brevis, Adductor Hallucis, Flexor Hallucis Brevis

4th layer: Planter Interossei (unipennate), Dorsal Interossei (bipennate)

MNEOMINIC for interossei action

PAD - (P)lantar (AD)duction
DAB - (D)ab (AB)duction

Question 4

1. 1. What is the action of the lumbrical muscles of the foot?
2. 2. Innervation

Answer 4

1.1. Flex the MTP joints while extending the IP joints

1.2.
1st lumbrical - medial plantar nerve
2-4th lumbrical - lateral plantar nerve

Side note: bipennate muscles - 2 sets of fibres which converge onto a central tendon

Question 5

The tarsal tunnel is a fibro-osseous space located between the medial tubercle of the calcaneus and medial malleolus

1.1. Name it’s contents

Answer 5

1.1. TOM DICK AND VERY NAUGHTY HARRY

Tibialis Posterior
Flexor Digitorum Longus
Posterior tibial artery and vein
Tibial nerve
Flexor Hallucis Longus