topic 20

Question 1

intrinsic muscles

Answer 1

Flexor Digitorum Brevis
Origin: Medial process of the calcaneal tuberosity.
Insertion: Middle phalanges of the toes (2nd to 5th).
Function: Flexes the lateral four toes at the metatarsophalangeal joints.
Innervation: Medial plantar nerve.

Abductor Hallucis
Origin: Medial process of the calcaneal tuberosity and the plantar aponeurosis.
Insertion: Medial side of the base of the proximal phalanx of the big toe.
Function: Abducts and flexes the big toe.
Innervation: Medial plantar nerve.

Flexor Hallucis Brevis
Origin: Medial part of the plantar surface of the cuboid and lateral cuneiform bones.
Insertion: Base of the proximal phalanx of the big toe.
Function: Flexes the big toe.
Innervation: Medial plantar nerve.

Flexor Digiti Minimi Brevis
Origin: Base of the fifth metatarsal bone.
Insertion: Base of the proximal phalanx of the little toe.
Function: Flexes the little toe.
Innervation: Lateral plantar nerve.

Quadratus Plantae
Origin: Medial border of the calcaneus.
Insertion: Tendon of the flexor digitorum longus.
Function: Assists in flexing the toes.
Innervation: Lateral plantar nerve.

Lumbricals (Four Muscles)
Origin: Tendons of the flexor digitorum longus.
Insertion: Extensor expansions of the lateral four toes.
Function: Flex the metatarsophalangeal joints and extend the interphalangeal joints of the lateral four toes.
Innervation: Medial and lateral plantar nerves.

the bottom surface that contacts the ground when standing or walking.

Question 2

extrinsic muscles

Answer 2

Flexor Digitorum Longus

Origin: Posterior surface of the tibia.
Insertion: Bases of the distal phalanges of the lateral four toes.
Function: Flexes the lateral four toes and assists in plantarflexion of the foot.
Innervation: Tibial nerve (S2-S3).

Flexor Hallucis Longus

Origin: Posterior surface of the fibula.
Insertion: Base of the distal phalanx of the big toe.
Function: Flexes the big toe and assists in plantarflexion of the foot.
Innervation: Tibial nerve (S2-S3).

Question 3

fascia

Answer 3

Fasciae
Plantar Aponeurosis (Plantar Fascia): A thick, fibrous band that spans the length of the foot from the calcaneus to the toes. It provides structural support to the foot arches and helps maintain foot biomechanics during weight-bearing activities.

+Compartments
The sole of the foot is often divided into medial, central, and lateral compartments based on the arrangement of muscles and fascial septa.

Question 4

vessels

Answer 4

Arteries

Medial Plantar Artery
Branch of the posterior tibial artery.
Supplies the medial aspect of the sole and toes.

Lateral Plantar Artery
Branch of the posterior tibial artery.
Supplies the lateral aspect of the sole and contributes to the plantar arch.

Veins
Venous drainage of the sole of the foot is primarily through the plantar venous arches, which eventually drain into the posterior tibial and fibular veins.

Question 5

nerves

Answer 5

Medial Plantar Nerve
Branch of the tibial nerve.
Supplies the intrinsic muscles on the medial side of the sole, except for the abductor hallucis.

Lateral Plantar Nerve
Branch of the tibial nerve.
Supplies the intrinsic muscles on the lateral side of the sole, including the abductor hallucis.