First & second layers of muscles of the sole

The FOOT

First & second layers of muscles of the sole

introduction The muscles acting on the foot can be divided into two distinct groups; extrinsic and intrinsic muscles. The extrinsic muscles arise from the anterior, posterior and lateral compartments of the leg. They are mainly responsible for actions such as eversion, inversion, plantarflexion and dorsiflexion of the foot. The intrinsic muscles are located within the foot and are responsible for the more fine motor actions of the foot, for example movement of individual digits.

First layer : Abductor Hallucis : -Origin: Originates from the medial tubercle of the calcaneus, -Insertion: It attaches to the medial base of the proximal phalanx of the great toe. -Actions: Abducts the great toe. -Innervation: Medial plantar nerve.

First layer : Abductor Digiti Minimi : -Origin: Originates from the medial and lateral tubercles of the calcaneus. -Insertion: It attaches to the lateral base of the proximal phalanx of the 5th digit (little toe). -Actions: Abducts the 5th digit. -Innervation: Lateral plantar nerve.

First layer : Flexor Digitorum Brevis : -Origin: Originates from the medial tubercle of the calcaneus. -Insertion: It attaches to the middle phalanges of the lateral four digits. It is perforated by the tendons of flexor digitorum longus. -Actions: Flexes the lateral four. -Innervation: Medial plantar nerve.

Second layer : Flexor digitorum accessories : -Origin: Originates from the medial and lateral plantar surface of the calcaneus. -Insertion: It attaches to the tendons of flexor digitorum longus. -Actions: Assists flexor digitorum longus by bringing the tendon more in line with toes, thus helps in flexing of the interphalangeal and metatarsophalangeal joints of the lateral four digits. -Innervation: Lateral plantar nerve.

Second layer : Lumbricals : -Origin: Originates from the tendons of flexor digitorum longus. -Insertion: Attaches partly to the extensor expansion and partly into the base of proximal phalanx of the lateral four digits. -Actions: Flexes at the metatarsophalangeal joints, while extending the interphalangeal joints of the lateral four toes. -Innervation: The most medial lumbrical is innervated by the medial plantar nerve. The remaining three are innervated by the deep division of lateral plantar nerve.

Second layer : Tendon of flexor digitorum longus : The tendon splits into four tendons for the lateral four toes. The tendon receives the insertion of the flexor digitorum accessorius and its slips give origin to the lumbrical muscles. Each slip perforate the the tendons of the flexor digitorum brevis to reach its insertion into the terminal phalanx.

Second layer : Tendon of Flexor hallucis longus : This tendon passes forward and medially and crosses deep to the tendon of the flexor digitorum longus to be inserted into the base of the terminal phalanx of the big toe.

THIRD AND FOURTH LAYERS OF THE FOOT

THE THIRD LAYER 1- FLEXOR HALLUCES BREVIS. 2-ADDUCTOR HALLUCIS. 3-FLEXOR DIGITI MINIMI BREVIS.

FLEXOR HALLUCIS BREVIS *origin: Cuboid and lateral cuniform. *Insertion: Base of proximal phalanx of the big toe. *Nerve supply: medial planter nerve. *Action: Flexion.

FLEXOR DIGITI MINIMI BREVIS *Origin: Base of 5 metatarsal and cuboid bone. *Insertion: Base of proximal phalanx of the little toe. *Nerve supply: Superficial division of lateral planter nerve. *Action: Flexion.

ADDUCTOR HALLUCIS *Origin: a- Transverse Head: Planter ligaments of metatarso phalangeal joint of lateral four toes. b- Oblique head: Base of 2 3 4 metatarsal bone. *Insertion: Lateral side of the base of proximal phalanx of the big toe. Action: a- Transverse Head: Maintain the transverse arch of the foot. b- Oblique Head: Adduction and Flexion

FOURTH LAYER 1- TENDON OF PERONEUS LONGUS. 2-TENDON OF TIBIALIS POSTERIOR. 3- PLANTER INTEROSSEI MUSCLE. 4- DORSAL INTEROSSI MUSCLE.

TENDON OF PERONEUS LONGUS it runs in a groove on the planter surface of the cuboid bone. it is inserted into the base of 1 metatarsal bone and the adjoining part of the medial cuneiform bone.

TENDON OF TIBIALIS POSTERIOR It divides into medial and lateral part. The medial part is inserted into the tuberosity of navicular bone and medial cuneiform bone. The lateral part is inserted into the other metatarsal bone except the talus and to the bases of 2 3 4 metatarsal bones.

PLANTER INTEROSSEI (PAD) ORIGIN: Lateral 3 metatarsal bones. INSERTION: The base of proximal phalanx and extensor expansion. ACTION: They adduct the lateral toes. they extend the interphalangeal joint and flex the metatarsophalangeal joint. NERVE SUPPLY: the first and second muscles are supplied by deep division of lateral planter nerve. the third muscle is supplied by the superficial division of lateral planter nerve.

DORSAL INTEROSSEI (DAB) ORIGIN: Adjoining sides of two metatarsal bones. INSERTION: Base of proximal phalanx and extensor expansion. ACTION: They abduct the 2 3 4 toes. They extend the interphalangeal joint and flex the metatarsophalangeal joint. NERVE SUPPLY:The first three muscle are supplied by deep division of lateral planter nerve. The fourth muscle is supplied by superficial division of lateral planter nerve.

PLANTER APONEUROSIS

PLANTER APONEUROSIS It is a dense sheet of fibrous tissue. Posteriorly, it is attached to medial and lateral tubercles of the calcaneus. Anteriorly, it divides into five slips. Tow intermuscular septa pass from the edges of the aponeurosis.

The lumbrical muscles, planter digital arteries and nerve can be seen between the slips of the planter aponeurosis. It protects the underlying vessels and nerves. It maintains the longitudinal arch.

the bones of the foot tarsus metatarsals phalanges

The muscles of the dorsum of the foot: *Extensor digitorum brevis: _has 4 tendons inserted into the medial 4 toes. *The medial slip passes to the proximal phalanx of the big toe and known as (Extensor hallucis brevis) *The lateral 3 slips join the extensor expansions of the corresponding toes.

Dorsal interossei: _inerted *partly into the base of the proximal phalanx. *partly into the extensor expansion. _ The action: *Abduction of the 2 nd, 3rd and 4 th toes. *Extension of the interphalangeal joints *Flexion of the metatarso-phalangeal joints.

Synovial sheaths obejectives Definition Injury Function Types

Definition A synovial sheath is one of the two membranes of a tendon sheath which covers a tendon. The other membrane is the outer fibrous tendon sheath Function it surround the tendons of muscles to facilitate their movements during action of these muscles and prevent their friction with surrounding structures.

Sheaths of extensor tendons:- 1-(tibialis anterior) ---> the sheath extends from the upper border of superior extensor retinaculum to the insertion

2- (extensor hallicus longus):- the sheath extends from the lower border of superior extensor retinaculum to the base of big toe

3- extensor digitorum longus & peroneus tertius) ---> the sheath extends from the lower border of (superior extensor retinaculum) to the middle of the dorsum of the foot

Synovial sheaths of peroneal tendons: - A single sheath surrounds the tendons of (peroneus longus and brevis.) -It begins alittle above the lateral malleolus -It passes with the tendons under cover of the (superior peroneal retinaculum).

-then it divides into two sheaths, one for each tendon which passes separately under the( inferior peroneal retinaculum) and runs to the insertion

Synovial sheaths of flexor tendons:- 1- (tibialis posterior)---> the sheath begins one inch above the flexor retinaculum and ends at the navicular bone

2- (flexor digitorum longus) ---> the sheath begins one inch above the flexor retinaculum and ends about the middle of the foot

3- (flexor hallicus longus)---> the sheath begins one inch above the flexor retinaculum and ends at the insertion of the tendon

Arches of the Foot

The bones of the foot are arranged in such a way to form two longitudinal arches and one transverse arch. The arches of the foot are the bony part that don t come in contact with the ground during standing. Falling of these arches lead to Flat foot

Functions : a spring. distribution. protection. Shock absorbtion.

The medial longitudinal arch: Posterior pillar: calcaneous Top: talus Anterior pillar: navicular, 3cunifoerm bone, med 3 metatarsals.

Factors keeping the medial longitudinal arch: Ligament: Medial part of planer aponeurosis,spring lig,deltoid lig,long and short planter ligament. Muscles: Tibialis pos,tibialis ant,flexor halllucis longus,flexor digitorm longus,short muscles of the sole Bony factor: the shape and conistitution of the bone keep the foot in the arching position

The lateral longitudinal arch: Posterior pillar: calcaneous Top: cuboid at the high point Anterior pillar: Lateral two metatarsal

Factors keeping the lateral longitudinal arch: Ligament: lateral part of planter aponeurosis, long and short planter ligament. Muscles: peroneous longus, flexor digitorm longus and short muscles of the little toe. Bony factors: the shape and conistitution of the bone keep the foot in the arching position.

The transverse arch: It is formed by: Bases of the metatarsal bones, cuboid and the three cuniforms (incomplete arch). Factors keeping the transverse arch: Bony Factor: Intermediate and lateral cuniforms are wedge-shaped. Ligament: Deep transverse lig. and interosseous ligs. Muscles: peroneus longus, tranverse head of adductor halluces,slips of tibialis posterior.

Anomalies of the foot Flat foot (pes planus): Rotation of the calcaneous,eversion of the plantar surface, slipping down of the talus and navicular, lengthening of the medial longitudinal arch and abduction of the forefoot.

Talipes equinovarus: plantar flexion,inversion and adduction o the forefoot.

Talipes calcaneovulgus: Dorsiflexion, eversion and abduction.