MUSCLE OF A FOOT 

There are four layers in muscle of a foot. 

1st layer of muscle of a foot :- 

1) Abductor hallucis brevis

2) Flexor digitorum brevis

3) Abductor digiti minimi

1) ADDUCTOR HALLUCIS BREVIS

ORIGIN: Oblique head—base of second to fourth metatarsal, sheath of peroneus longus tendon; transverse head-plantar metatarsophalangeal ligaments of lateral three toes.

INSERTION: Lateral side of base of proximal phalanx of great toe.

NERVE SUPPLY: Lateral plantar nerve (S2, S3).

ACTION: Adducts great toe.

2) FLEXOR DIGITORUM BREVIS

ORIGIN: Calcaneal tuberosity, plantar aponeurosis, intermuscular septa.

INSERTION: Tendons divide and attach to the both sides of the middle phalanges of second to fifth toes.

NERVE SUPPLY: Medial plantar nerve (S1, S2).

ACTION: Flexes proximal interphalangeal joints and metatarsophalangeal joints of lateral four toes.

3) ABDUCTOR DIGITI MINIMI (FOOT)

ORIGIN: Medial and lateral process of the calcaneal tuberosity, plantar aponeurosis, intermuscular septum.

INSERTION: Lateral side of base of proximal phalanx of fifth toe.

NERVE SUPPLY: Lateral plantar nerve (S1–S3).

ACTION: Abducts fifth toe.

2nd layer of  muscle of foot :-

1) Flexor hallucis longus

2) Flexor digitorum longus

3) Flexor digitorum accesories

4) Lumbrical 

1) FLEXOR HALLUCIS LONGUS 

3) FLEXOR DIGITORUM ACCESSORIUS

ORIGIN: Medial head—medial tubercle of calcaneus, lateral head—lateral tubercle of calcaneus and long plantar ligament.

INSERTION: Flexor digitorum longus tendon.

NERVE SUPPLY: Lateral plantar nerve (S1–S3).

ACTION: Flexes distal phalanges of lateral fourth toes.

3rd layer of muscle of a foot  :- 

1) Adductor hallucis 

2) Flexor hallucis brevis

3) Flexor digiti minimi brevis 

1) ADDUCTOR HALLUCIS

ORIGIN: Oblique head—base of second to fourth metatarsal, sheath of peroneus longus tendon; transverse head-plantar metatarsophalangeal ligaments of lateral three toes.

INSERTION: Lateral side of base of proximal phalanx of great toe.

NERVE SUPPLY: Lateral plantar nerve (S2, S3).

ACTION: Adducts great toe.

2) FLEXOR HALLUCISL BREVIS

ORIGIN: Medial side of plantar surface of cuboid, lateral cuneiform.

INSERTION: Medial and lateral side of base of proximal phalanx of great toe.

NERVE SUPPLY: Medial plantar nerve (S1, S2).

ACTION: Flexes metatarsophalangeal joint of great toe.

3) FLEXOR DIGITI MINIMI BREVIS (FOOT)

ORI GIN: Plantar aspect of base of fifth metatarsal, sheath of peroneus longus tendon.

INSERTION: Lateral side of base of proximal phalanx of fifth toe.

NERVE SUPPLY: Lateral plantar nerve (S2, S3).

ACTION: Flexes fifth metatarsophalangeal joint, supports lateral longitudinal arch.

4th layer of muscle of a foot :-

1) Palmar interrosei

2) dorsal interrosei 

3) Peroneus longus

4) Tibialis posterior

1) PLANTAR INTEROSSEI

ORIGIN : Base and medial side of lateral three toes.

INSERTION: Medial side of base of proximal phalanx of same toes and dorsal digital expansions.

NERVE SUPPLY: Lateral plantar nerve (S2, S3).

ACTION: Adduct third to fifth toes, flex metatarso- phalangeal joints of lateral three toes.

2) DORSAL INTEROSSEI

3) PERONEUS LONGUS

ORIGIN: Lateral tibial condyle, upper 2/3 of lateral surface of fibula, intermuscular septa.

INSERTION: Lateral side of base of first metatarsal, medial cuneiform.

NERVE SUPPLY: Superficial peroneal nerve (L5, S1).

ACTION: Everts and plantar flexes ankle.

4) TIBIALIS POSTERIOR

ORIGIN: Tibia (lateral aspect of posterior surface, below soleal line, interosseous membrane, upper half of posterior surface of fibula, deep transverse fascia).

INSERTION: Tuberosity of navicular, medial cuneiform, sustentaculum tali, intermediate cuneiform, base of second to fourth metatarsals.

NERVE SUPPLY: Tibial nerve (L4,5).

ACTION: Plantar flexes and inverts ankle.