Ankle, Plantar Foot

Question 1

Flexor Digitorum Longus

Deep Muscle Group

Answer 1

Origin:
Medial part of posterior surface of tibia inferior to soleal line and by a broad tendon to fibula

Insertion:
Bases of distal phalanges of lateral four digits

Innervation:
Tibial nerve (S2, S3)

Action:
Flexes lateral four digits; plantarflexes ankle; supports longitudinal arches of foot

Question 2

Flexor Hallucis Longus

Deep muscle group

Answer 2

Origin:
Inferior two thirds of posterior surface of fibula and inferior part of interosseous membrane

Insertion:
Base of distal phalanx of great toe (hallux)

Innervation:
Tibial nerve (S2, S3)

Action:
Flexes great toe at all joints; weakly plantarflexes ankle; supports medial longitudinal arch of foot

Question 3

Tibialis Posterior

Deep muscle group

Answer 3

Origin:
Interosseous membrane, posterior surface of tibia inferior to soleal line, and posterior surface of fibula

Insertion:
Primarily to tuberosity of navicular; also to cuneiforms, cuboid, and bases of 2nd–4th metatarsals

Innervation:
Tibial nerve (L4, L5)

Action:
Plantarflexes ankle; inverts foot; supports medial longitudinal arch of foot

Question 4

Abductor Hallucis

First Layer

Answer 4

Origin:
Medial tubercle of tuberosity of calcaneus, flexor retinaculum, and plantar aponeurosis

Insertion:
Medial side of base of proxi- mal phalanx of 1st digit

Innervation:
Medial plantar nerve (S2, S3)

Action:
Abducts and flexes 1st digit (great toe, hallux)

Question 5

Flexor Digitorum Brevis

First Layer

Answer 5

Origin:
Medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa

Insertion:
Both sides of middle phalanges of lateral four digits

Innervation:
Medial plantar nerve (S2, S3)

Action:
Flexes lateral four digits

Question 6

Abductor Digiti Minimi

First Layer

Answer 6

Origin:
Medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa

Insertion:
Lateral side of base of proximal phalanx of 5th digit

Innervation:
Lateral plantar nerve (S2, S3)

Action:
Abducts and flexes 5th digit

Question 7

Quadratus Plantae

Second layer

Answer 7

Origin:
Medial surface and lateral margin of plantar surface of calcaneus

Insertion:
Posterolateral margin of tendon of flexor digitorum longus

innervation:
Lateral plantar nerve (S2, S3)

Action:
Assists flexor digitorum longus in flexing lateral four digits

Question 8

Lumbricals

Second layer

Answer 8

Origin:
Tendons of flexor digitorum longus

Insertion:
Medial aspect of expansion over lateral four digits

Innervation:
Medial one: medial plantar nerve (S2, S3) Lateral three: lateral plantar nerve (S2, S3)

Action:
Flex proximal phalanges; extend middle and distal phalanges of lateral four digits

Question 9

Deltoid Ligament

Answer 9

Medial Ligament of Ankle joint

Made up of:

anterior tibiotalar, posterior tibiotalar, tibiocalcaneal,
tibionavicular

function:
medial ligament stabilizes the ankle joint during eversion of the foot and prevents subluxation

Question 10

Medial longitudinal ligament

Answer 10

composed of the calcaneus, talus,
navicular, three cuneiforms, and three metatarsals

Muscle:
Tibialis anterior/posterior
Fibularis longus

Question 11

Lateral longitudinal ligament

Answer 11

Bones: calcaneus, cuboid, lateral 2 metatarsals

Anterior/posterior talofibular ligament
Calcaneofibular ligament
Medial ligament

Question 12

Transverse arch

Answer 12

Bones: cuboid, cuneiform, base of metatarsals

Muscles:
Tendon of fibularis longus, tibialis posterior