Plantar

• Origin. From the bases of three of the metatarsals.

• Insertion. Into the dorsal extensor expansions and the sides of the proximal phalanges.

• Actions. Adduction of the toes and assisting the other actions of the dorsal interossei.

• Nerve supply. Lateral plantar nerve.

Lateral group

Abductor digiti minimi (m. abductor digiti minimi/мышца, отводящая мизинец стопы)

• Origin. From the calcaneal tuberosity.

• Insertion. To the proximal phalanx of the little toe.

• Actions. Flexion and abduction of the little toe.

• Nerve supply. Lateral plantar nerve.

Flexor digiti minimi brevis (m. flexor digiti minimi brevis/короткий сгибатель мизинца стопы)

• Origin. From the base of the 5^th metatarsal.

• Insertion. Into the proximal phalanx of the little toe.

• Action. Flexion of the little toe.

• Nerve supply. Lateral plantar nerve.

Opponens digiti minimi (m. opponens digiti minimi/мышца, противопоставляющая мизинец стопы)

• Origin. From the long plantar ligament, it fuses with flexor digiti minimi.

• Insertion. The fifth metatarsal bone.

• Action. Opponens the little toe.

• Nerve supply. Lateral plantar nerve.

Fasciae of the leg and foot

The deep fascia of leg (fascia cruris/фасция голени)

• This fascia surrounds the leg and fuses with the bones where they are uncovered by muscles.

• On the posterior surface of the leg the fascia consists of two layers. The superficial layer covers the gastrocnemius and soleus muscles. The deep layer lies between these muscles and the deep posterior muscles.

• On the lateral side the fascia gives off two intermuscular septa, which penetrate deeply and attach to the fibula.

• The anterior intermuscular septum of leg (septum intermusculare cruris anterius/передняя межмышечная перегородка голени) passes in front of fibular muscles.

• The posterior intermuscular septum of leg (septum intermusculare cruris posterius/задняя межмышечная перегородка голени) passes behind the fibular muscles.

• On the anterior surface of the leg above the malleoli fibres blend with the fascia to form a transverse band between the leg bones, the superior extensor retinaculum (retinaculum musculorum extensorum superius/верхний удерживатель сухожилий разгибателей). This ligament presses the tendons of the anterior leg muscles to the bones.

• The inferior extensor retinaculum (retinaculum musculorum extensorum inferius/нижний удерживатель сухожилий разгибателей) is located distally in front of the ancle joint. It has two bands in shape the letter Y.

• Both retinaculum give rise to a septum that penetrate deeper and form four osteofibrous canals.

• The lateral canal transmits the tendon of the extensor digitorum longus and the fibularis tertius muscles

• The next canal transmits the tendon of the extensor hallucis longus muscle.

• The medial canal transmits the tendon of the tibialis anterior muscle.

• The fourth canal is located behind the middle one contains vessels and nerve.

The tendons passing through the canals are invested in the synovial sheaths.

• Thickening of the fascia behind medial molleolus forms the flexor retinaculum (retinaculum musculorum flexorum/удерживатель сухожилий сгибателей) passing from the calcaneus to the medial malleolus. The retinaculum give rise to a septum that penetrate deeper and form three osteofibrous canals.

• The anterior canal transmits the tendon of the tibialis posterior.

• The middle canal transmits the tendon of the flexor digitorum longus.

• The posterior canal transmits the tendon of the flexor hallucis longus.

• The superficial canal transmits the vessels and nerve.

The tendons passing through the canals are invested in the synovial sheaths.

• Thickenings of the fascia behind lateral molleolus form the superior and inferior fibular retinaculum (retinaculum musculorum fibularium superius, inferius/верхний, нижний удерживатель сухожилий малоберцовых мышц).

• The superior fibular retinaculum stretching from the malleolus to the calcaneus over the tendons of the fibularis longus and brecis muscles, which lie under it in a common osteofibrous canal.

• Distally both tendons pass under inferior fibular retinaculum attached to the lateral surface of calcaneus. The space under the inferior fibular retinaculum is divided by a septum into two canals transmitting each tendon separately.

The tendons of the fibular muscles are invested in a common synovial sheath, wich divides distally into two parts corresponding to the two canals under the inferior fibular retinaculum.

The dorsal fascia of foot (fascia dorsalis pedis/тыльная фасция стопы)

This fascia is located below the inferior extensor retinaculum and has two layers.

• The superficial layer covers the tendons of extensor muscles.

• The deep layer covers the dorsal interossei muscles.

The plantar aponeurosis (aponeurosis plantaris/подошвенный апоневроз)

• It passes from the calcaneal tuberosity and towards the toes it expands and separates into five slips between which there are transverse fibres.

• Two vertical septa arise from the edges of the aponeurosis, pass upwards between the muscles. These septa divide the sole into three compartments which correspond to the three groups of muscles of the sole.