Podiatry

Dorsal Venous arch:
Gives rise to saphenous vein medially and
gives rise to lesser saphenous vein laterally.

The saphenous vein is located in front of the medial malleoli.
Deep Fascia of the dorsum of the Foot

Deep Fascia of the dorsum of the foot is continuous with the fascia cruris via extensor retinacula.
Deep fascia blends in with the plantar fascia medially and laterally.
Deep fascia is the roof of the first fascial space of the dorsum of the foot.
Three layers on dorsum of the foot.

First layer of the dorsum of the foot

First layer lies between the superficial part of the dorsalis pedis.
Contains AT, EHL, EDL and Peroneus tertius.
All these tendons are in synovial sheaths which are three in number.
AT and EHL have seperate tendon sheaths and EDL & Peroneus Tertius have their own.

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2nd Layer of the dorsum of the foot

Contains one intrinsic muscle of the foot Extensor digitorum brevis and fascial coverings.
Fascial coverings are the deep layer of the dorsalis pedis fascia.
Extensor digitorum Brevis from the anterior aspect of the dorsum of the calcaneus divides into four tendons and passes into medial 4 toes.
* There is no extensor digitorum brevis on the 5th toe.


Extensor Digitorum Brevis:

Origin: Superior aspect of the calcaneus anterior to the sinus tarsai, partially from the interosseous talocalcaneal ligament.
Insertion: splits into 4 slips, most medial one the EHB inserts on the dorsal aspect of the base of the proximal phalanx of the hallux, other 4 slips on the lateral side of the EDL (extensor digitorum longus) of 2nd, 3rd and 4th toes - contributes to extensor expansion.
Action: Extend phalanges of 2nd/3rd/4th toes, helps with MPJ (metatarsophalangeal joints) extension.
Nerve: Deep peroneal nerve, lateral branch; dorsalis pedis artery via lateral branch.
Layers of the Foot:
Compartments of the plantar surface of the foot:

Dorsally there are 3 compartments.
Plantarly there are 4 compartments.
The dorsal and plantar compartments are seperated by:
dorsal interossei, aponeurosis and metatarsals.

Medial compartments: abd. hallucis, FHB, FHL (flexor hallucis brevis and flexor hallucis longus)

Central Compartment: Flexor digitorum brevis, flexor accessorius, adductor hallucis.

Lateral compartment: Abductor digiti minimi, flexor digiti minimi brevis.

Interosseus compartment.

First Layer Muscles:
Abductor hallucis, flexor digitorum brevis and abductor digiti minimi.

Abudctor Hallucis:
Origin: medial process of calcaneal tuberosity, flexor retinaculum, medial intermuscular septum.

Insertion: medial plantar aspect of the proximal phalanx of the hallux.

Action: abducts and plantarflexes toes.

Nerve: medial plantar nerve and artery.

Flexor Digitorum Brevis:
Origin: medial process of the calcaneal tuberosity, medial and lateral intermuscular septa.

Insertion: middle phalanges of the toes (except for the hallux)

Action: Flexes toes at PIPJ and MPJ

Nerve: medial plantar artery and nerve.



Abductor digiti minimi:

Origin: Lateral process of calcaneal tuberosity.
Insertion: lateral plantar aspect of the proximal phalange of the 5th toe.
Action: Abduct and flex fifth toe.
Nerve: Lateral plantar nerve and artery.