The compartment of the little toe It lies under the lateral planter fascia and is bounded by the lateral intermuscular septum medially and by the attachment of the fascia to the dorsum of the fifth metatarsal bone laterally. It includes the abductor and flexor digiti minimi muscles and the fifth metatarsal bone.

Little toe compartment

The central compartment of the sole It lies deep to the planter aponeurosis. It is bounded on either side by the medial and lateral intermuscular fascia It contains the flexor digitorum brevis muscle, the tendons of the flexor digitorum longus and its associated muscles ( quadratus plantae and four lumbrical muscles), the tendon of the flexor hallucis longus muscle and the lateral planter nerve and vessels.

The central compartment

Lumbrical muscles They arise from the medial side of the lateral 4 flexor digitorum longus tendons then incline superiorly and inserted in the base of the proximal phalanx and extensor expansion. Nerve supply: the 1st one supply by the medial planter nerve. The other 3 muscles supplied by the lateral planter nerve. Action: they are weak muscles play a part in the flexion of the metatarsophalangeal joints of the lateral 4 toes.

Lumbrical muscles

Lateral planter nerve The smaller of the two planters nerves arising from the tibial nerve under the abductor hallucis muscle has a distribution like the ulnar nerve in the hand. The nerve pass between flexor digitorum brevis and quadratus plantae muscles. it gives: muscular branches to the abductor digiti minimi and quadratus plantae muscles. articular branches.

At the lateral margin of the quadratus plantae muscle the nerve divided into superficial and deep branches. The deep branch descends deeply into the adductor –interosseous compartment.

The superficial branch divided into proper digital branch to the lateral side of the little toe supply the flexor digiti minimi muscle, and a common digital branch communicates with the third common branch of the medial planter nerve and divides into two proper digital branches to the adjacent sides of the fourth and fifth toes.

Lateral planter artery It is the larger of the two terminal branches of the posterior tibial artery. Arise deep to the flexor retinaculum then pass deep to the abductor hallucis and flexor digitorum brevis ms. runs lateral to the corresponding nerve. At the medial side of the fifth metatarsal bone the artery sinks deeply, on reaching the base of the 5th metatarsal bone the artery curve medially across the proximal ends of the second, third and fourth metatarsal bones to form the planter arch.

The interosseous- adductor compartment It is the deepest plane of the sole of the foot, it lies between the dorsal interosseous fascia and the periosteum of the metatarsal bones inferiorly, and the planter interosseous fascia covers the superficial surface of the adductor hallucis muscle superiorly.

This compartment contain the dorsal and planter interosseous muscles, the adductor hallucis muscle, the planter arch, the deep branch of the lateral planter nerve, and the dorsal metatarsal branches of the dorsalis pedis artery.

The planter arch It is formed from the lateral planter artery, the arch completed medially by its union with the deep planter branch of the dorsalis pedis artery which reaches the sole through the proximal end of the first intermetatarsal space. The arch lies across the bases of the central metatarsal bones and deep to the adductor hallucis muscle. The arch gives:

four planter metatarsal arteries run between the metatarsal bones, each artery divided into pairs of proper digital arteries supply the adjacent sides of the toes. The proper digital artery to the lateral side of the little toe arise from the lateral planter artery opposite the base of the fifth metatarsal bone. Each planter metatarsal artery gives an anterior perforating branch which passes through the interosseous space anastomosed with the corresponding branch of the dorsal metatarsal artery.

The perforating branches arise from the arch, passes through the proximal ends of the lateral three intermetatarsal spaces and between the heads of the dorsal interosseous muscles to join the dorsal metatarsal arteries.

Deep branch of the lateral planter nerve Sinks into the interosseous –adductor compartment with the lateral planter artery and passes medially across the bases of the metatarsal bones posterior to the planter arch. It gives:

1- muscular branches to the lateral 3 lumbrical muscles, the adductor hallucis m. The interosseous muscles. 2- articular branches to the intertarsal and tarsometatarsal joints.

The interosseous muscles They are 3 planter to the lateral 3 toes and 4 dorsal to the middle 3 toes. The dorsal interosseous muscles arise from adjacent sides of metatarsal bones of the space in which they lie.

The planter lnteroseous muscles arise from the bases and the medial sides of the metatarsal bones into which they insert. All the interosseous muscles inserted in the base of the proximal phalanges. Only the dorsal interosseous muscles inserted in the extensor expansion of the extensor digitorum longus.

Nerve supply is the lateral planter nerve. Action: the planter interosseous adduct the lateral toes. The dorsal interosseous abduct the middle 3 toes.

Dorsal interosseous

Lymphatic drainage of the lower limb Superficial inguinal lymph nodes: lie in the superficial fascia below the inguinal ligament divided into horizontal and vertical groups. The horizontal group lies just below and parallel to the inguinal ligament, the medial one receive the superficial lymphatic vessels from the anterior abdominal wall below the level of the umbilicus and from the perineum. The lateral one receive superficial lymphatic vessels from the back below the iliac crest.

The vertical group lies along the terminal part of the great saphenous vein and receive the majority of the superficial lymphatic vessels from the lower limb. Efferent vessels from the superficial lymph nodes pass through the saphenous opening to the deep inguinal nodes.

Deep inguinal lymph nodes Are variable in number but they are commonly three. They lie along the medial side of the femoral vein, the most superior one located in the femoral canal receive lymphatic vessels from the superficial inguinal nodes and also from the deep structures of the lower limb. The efferent vessels from these nodes pass to the external iliac nodes through the femoral canal.

Popliteal lymph nodes are embedded in the fatty tissue of the popliteal fossa. They receive superficial lymph vessels from the lateral side of the foot and leg accompany the small saphenous vein, they also receive lymphatic vessels from the knee joint and the deep lymphatic vessels accompany the anterior and posterior tibial arteries.