Dr. Sangeeta Kotrannavar Assistant Professor Dept. of Anatomy USM-KLE IMP, Belagavi

 Describe the blood supply and nerve supply in each compartment of leg

 Explain the arches of the and its significant  State the four layers of muscles in the of the foot  Describe the blood supply and innervation of the sole of the foot  Describe the tarsal tunnel and its contents  Describe the applied anatomy of the foot

 Tarsus-7  Metatarsus-5 (I-V)  Phalanges-14

Regions of foot  Plantar (sole)-part contacting ground  Dorsal- part directing superiorly  Heel – sole underlying

 Calcaneus (Latin w. for heel)  Talus (Latin w. for ankle)  Cuboid  Navicular  Three cuneiforms

Anterior view Lateral view  The foot and its bones may be considered in terms of three anatomical and functional parts

 The hindfoot: talus and calcaneus  The midfoot: navicular, cuboid, and cuneiforms.  The forefoot: metatarsals and phalanges. Talocalcaneanavicular joint navicular

talus

calcaneus

Sagittal section of the foot showing talocrural and tarsal joints. (From Sobotta 2006.)  There are five metatarsals in the foot, numbered I to V from medial to lateral

 Metatarsal I, associated with the great , is shortest and thickest head  Each metatarsal has a head at the distal end, an elongate shaft in the middle, and a proximal base base  The head of each metatarsal articulates with the proximal phalanx of a toe

 The base articulates with one or more of the distal group of tarsal bones  The great toe (L. hallux) is also crescent-shaped called the 1st toe

head  The little toe (L. digitus minimus) shaft is also called the 5th toe base head  Consists of a base, a shaft, and a shaft distal head base

 The head of each distal phalanx is non-articular and flattened into a crescent-shaped plantar tuberosity under the plantar pad at the end of the digit

 The bones of the foot do not lie in a horizontal plane  Instead, they form  Longitudinal arch  Transverse arch  It absorb and distribute downward forces from the body during standing and moving on different surfaces  Anterior transverse arch is round shaped, formed by heads of 1-5 metatarsals, complete arch

 Posterior transverse arch is wedge shaped, formed by navicular, 3 cuniforms, base & shaft of metatarsals, incomplete Lateral view

 is formed between the posterior end of the calcaneus and the heads of the metatarsals  the medial part of the longitudinal arch is highest  the lateral part is lowest

: Ligaments

 Ligaments and muscles support the arches of the foot  Ligaments that support the arches include  plantar aponeurosis  plantar calcaneocuboidal  long plantar ligaments  plantar calcaneonavicular Muscles

 Fibularis longus, tibialis anterior, and tibialis posterior muscles, which all insert on the undersurfaces of bones on the medial side of the foot, together act as a stirrup to support the arches of the foot

 Fibularis longus supports mainly the lateral and transverse arches.

Extensor digitorum brevis  This is a small muscle situated on the lateral part of the dorsum of foot, deep to the tendons of the extensor digitorum longus  Nerve Supply- Lateral terminal branch of the deep peroneal nerve Extensor digitorum  Actions brevis  Extensor hallucis brevis - extends MTP joint of the great toe. Extensor hallucis  Extensor digitorum brevis - extend MTP and brevis interphalangeal joints of the second, third and fourth , particularly in a dorsi-flexed foot  It bind the tendons of the anterior compartment muscles  The superior extensor retinaculum  is a strong, broad band of deep fascia, passing from the fibula to the tibia  The inferior extensor retinaculum,  a Y-shaped band of deep fascia. The stem of the Y lies laterally, attached to the anterosuperior surface of the calcaneus and upper band to medial malleolus and lower bands to plantar superior & inferior aponeurosis extensor  The structures passing under cover of the retinaculum extensor retinacula are muscles, nerve & of ant. compartment

Flexor retinaculum  formed by deep fascia of post. Compartment  Attached between tip of the medial malleolus & medial tubercle of the calcaneum

Peroneal retinaculum  Superior peroneal retinaculum- It holds the peroneal tendons in place against the back of the lateral malleolus. It is attached between lateral malleolus & calcaneum  Inferior peroneal retinaculum is situated anteroinferior to the lateral malleolus. Flexor Sup. & inf.peroneal retinaculum retinaculum-  on the posteromedial side of the ankle  a depression formed by the medial malleolus of the tibia, the medial and posterior surfaces of the talus and the medial surface of the calcaneus  an overlying flexor retinaculum  contains : vessels, flexor tendons and nerve

 The holds the parts of the foot together, helps protect the sole from injury, and helps support the longitudinal arches of the foot.  The thick, central part plantar fascia forms the strong plantar plantar aponeurosis aponeurosis  The plantar aponeurosis arises posteriorly from the calcaneus and distally divides into 5 bands & continuous with the fibrous digital sheaths

 From the medial and lateral margins of the aponeurosis, the lateral and medial vertical intermuscular septa pass deeply, and divide the plantar muscles into three groups—medial, intermediate, and lateral.  The thinner transverse septa arise from the vertical septa and divide the muscles of the sole into four layers. Muscles in the sole of the foot are organized into 4 layers:

1) First layer - contains abductor hallucis, flexor digitorum brevis, abductor digiti minimi

2) Second layer - contains quadratus plantae, lumbricals

3) Third layer – contains flexor hallucis brevis, flexor digiti minimi brevis, adductor hallucis

4) Fourth layer – contains dorsal interossei, plantar interossei

Muscle Innervation Action

Abductor Medial Abducts hallucis plantar n. great toe Flexor Flexes lateral digitroum 4 toes brevis Abductor Lateral Abducts Abductor digiti plantar n. little toe hallucis minimi Abductor digiti minimi Flexor Ab –Flexor-Ab digitorum brevis Lumbricals

Muscle Innervation Action

Quadratus Lateral plantar Assist flexor plantae n. digitorum longus in (flexor flexing the toes digitorum accessorium) Lumbricals 1st – medial Maintain extension of -4 plantar nerve lateral four digits at 2nd, 3rd, 4th – interphalangeal joints. lateral (toes do not buckle plantar nerve under during walking or running)

Quadratus plantae Muscle Innervat Action Adductor ion hallucis Flexor Medial Flexes proximal hallucis plantar n. phalanx of 1st brevis digit at MPJ Adductor Lateral Adducts great hallucis plantar n. toe at MPJ Flexor Flexes little toe digiti at MPJ Flexor hallucis minimi Flexor brevis brevis digiti minimi Flexor –AD-Flexor brevis MPJ = Metatarsophalangeal joint

Plantar Muscle Innervatio Action interossei n

Plantar Lateral Adduct digits P-AD interossei plantar n. and flex (3 in no. at 3- MPJs th 5 toes) Dorsal Dorsal Abduct digits interossei D-AB interossei and flex (4 in no. at 2- MPJs 5th digit)

MPJ = Metatarsophalangeal joint  Anterior tibial artery Anterior tibial artery 

Fibular artery Posterior tibial artery

Ant. Tibial supplies anterior compartment

Branches Dorsalis pedis - Imp for artery pulsation in peripheral neuropathy

 Originate from

 Passes into anterior compartment through gap in superior part of interosseous membrane

 Descends on this membrane between tibialis anterior and extensor digitorum longus

 Distributed around the anterior compartment of leg  is the continuation of the anterior tibial artery

 begins as it crosses the ankle joint  passes anteriorly over the dorsal aspect of the talus, navicular, and intermediate cuneiform bones arcuate artery dorsal metatarsal  then it passes inferiorly, as the deep plantar artery, between the two heads of the first dorsal interosseous muscle to join the deep in the sole of the foot dorsal digital arteries Imp artery pulsation in peripheral neuropathy

Branches

Posterior tibial artery supplies posterior and lateral compartments of leg

 Posterior tibial artery bifurcates into a small medial plantar artery and a much larger lateral plantar artery  Plantar arch is formed by the direct

continuation of the lateral plantar Deep plantar arch artery, and is completed medially by

the dorsalis pedis artery. lateral plantar artery Medial plantar artery  lies between to third and fourth layers of the sole.

Arteries in the sole of the foot.

Popliteal artery  It begins at the lower border of the popliteus, between the tibia and the fibula, deep to the gastrocnemius. Anterior tibial artery  It enters the back of leg by passing deep to the tendinous arch of the soleus Fibular artery  It terminates deep to flexor retinaculumPosterior tibial artery by dividing, into the lateral and medial plantar arteries  Distribution:Posterior and lateral compartments of leg  Branches The peroneal artery, Several muscular branches, Nutrient artery & anastomotic branches  bifurcates into a small medial plantar artery and a much larger lateral plantar artery

 The fibular artery arises from the posterior tibial artery

 Descends in posterior compartment adjacent to posterior intermuscular septum

 Distributed along the posterior compartment of leg: perforating branches supply lateral compartment of leg

Post comp

Lat. Comp Ant. Comp

 The larger sciatic component  Derived from the ventral branches (anterior division) of the L4 , L5 and S1 to S3 ventral rami  It descends along the back of the thigh and popliteal fossa  then enters into the posterior compartment of the leg, by passing deep to the tendinous arch of origin of the soleus along with the posterior tibial vessels  It terminates deep to the flexor retinaculum by dividing into medial and lateral plantar nerves.  Supplies posterior compartment  derived from the dorsal branches of the L4, L5 and S1, S2 ventral rami

 It descends obliquely along the lateral Deep side of the popliteal fossa to the fibular head

 It curves lateral to the fibular neck, deep to peroneus longus, and divides into superficial and deep peroneal nerves.  Arises from division of common fibular nerve at the neck of fibula

 Descends in the lateral compartment of the leg

 Pierces deep fascia at distal third of the leg to become subcutaneous and supply the skin on the lateral side of the leg & dorsum of foot

 It supplies: 1) Fibularis longus muscle 2) Fibularis brevis muscle  one of the two terminal branches of the common fibular nerve, is the nerve of the anterior compartment & dorsum of foot

 arises between the fibularis longus muscle and the neck of the fibula

 after entering the compartment, the nerve accompanies the anterior tibial artery

 innervates all muscles in the anterior compartments & extensor digitorum brvis tibial nerve

 The tibial nerve divides lateral plantar nerves posterior to the medial malleolus into medial plantar nerves  the medial and lateral plantar nerves  These nerves supply the intrinsic muscles of the foot, except for  the extensor digitorum brevis and extensor hallucis brevis, which are supplied by the deep fibular nerve proper plantar digital nerve

 Similar to median nerve of hand

 Similar to ulnar nerve of hand Cutaneous innervation Applied 1. Walks on heel

2. Walks on toes

3. Walks on lateral border of foot: Pes varus /bow-legg (pes –foot, varus -inward).

4. Walks on medial border of: Pes valgus / know knee (pes –foot, valgus -outward)

Applied  Damage to the deep peroneal nerve, as is possible with traumatic injury to the lateral knee, results in foot drop. OSPE

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D Self study

Forearm leg Flexor muscles Extensor muscles