Dorsum of the Foot Anatomy PDF

386 lextbook of Anatorny: Abdormen and Lower Limb and forms a fleshy muscle present on the dorsm of...

386 lextbook of Anatorny: Abdormen and Lower Limb and forms a fleshy muscle present on the dorsm of the foot The young DORSUM OF THE FOOT Swelling anterior to the lateral malleolus. diagnose it as a contusion. novice doctors sometime SENSORY INNERVATION OF THE DORSUM OF THE FOOT (FIG. 28.14) AN 18.2 Origin superior surface of The sensory innervation to the dorsum of the foot is pro It arises from the anterior part of the the stem of infe vided by the following four sets of nerves: calcaneun, medial to the attachment of 1. Superficial peroneal nerve (also called mnuscu rior extensor retinaculum. locutaneous nerve of leg): It is a branch of com mon peroneal nerve. It provides sensory innervation Insertion to most of the dorsum of the foot except che skin of The muscle divides into four tendons for the medial four dorsalis the cleft between the first and second toes. It also toes. The tendon to the big toe crosses in front of supplies medial margin of the great toe. pedis artery and inserts on the dorsal surface of the proxi 2. Deep peroneal nerve: It is a branch of common mal phalanx of the big toe. The lateral three tendons join peroneal nerve. It provides innervation to the cleft the lateral side of the tendons of the EDL to the second. between the first and second toes. third, and fourth toes. 3. Sural nerve: It is a branch of tibial nerve. It sup plies lateral margin of the dorsum of the foot N.B. and lateral margin of the little toe. 4. Saphenous nerve: It is a branch of posterior divi Medial-most part of the extensor digitorum brevis, which forms sion of femoral nerve. It supplies medial margin of the tendon for the big toe, separates or becomes distinct early. the foot up to the head of the first metatarsal/base It is known as extensor ballucis brevis. of great toe. MUSCLES OF THE DORSUM OF THE FOOT Nerve supply These are as follows: It is by the lateral terminal branch of the deep peroneal (a) Extrinsic tendons of the muscles of the anterior nerve. compartment of the leg (namely tibialis anterior, EHL, EDL, and peroneus tertius). Actions (b) Intrinsic muscle on the dorsum of the foot is only one 1. Extensor hallucis brevis (EHB) extends the meta - the extensor digitorum brevis. tarsophalangeal joint of the big toe. 2. The other three tendons extend the metatar Extensor Digitorum Brevis (Fig. 28.15) sophalangeal and interphalangeal joints of second, It is a small muscle situated on the lateral part of the dor third, and fourth toes, particularly when the foot is sum of the foot, deep to the tendons of EDL. It is the ony dorsiflexed. Superficial - peroneal nerve Medial branch Superficial -Saphenous nerve Lateral branch peroneal Saphenous nerve nerve Sural nerve Sural nerve Deep peroneal nerve Deep peroneal nerve, supplying Lateral plantar first interdigital nerve cleft -Medial plantar A B nerve FIG. 28.14 Sensory innervation of the dorSum of the toot. (A) CUtaneous nerves. (B) Territories of the cutaneous nerves.  Front of the Leg and Dorsum of the Foot Course (Fig. 28.16) It begins in CHAPTER 28 387 front of ankle malleoli.ofIt passes between medial and lateral dorsum the foot forward along to reach the the medial side of the Anteriorofpartcalcaneus of intermetatarsal the two heads ofspace, where it proximal end of the first the first dorsaldips downward between surface superior enter the sole of the foot interosseous muscle to with the lateral where it ends by Extensor digitorum brevis plantar artery. anastomosing Relations Dorsalis pedis artery Superficial: the EHB lateral to crosses the artery Extensor hallucis medial side. Deep: Ankle joint superficially from brevis Medial: Tendon ofand tarsal the EHL.bones. Lateral: First tendon of the EDL. Dorsum of proximal N.B. phalanx of big toe Variations of dorsalis pedis artery: (a) In about 14% of be replaced by the cases, it may Tendons of extensor may be too large to perforating branch of the peroneal artery. (b) It digitorum longus artery of the sole of foot.compensate for the small lateral plantar Branches FIG. 28.15 " Lateral and Origin and insertion of extensor medial tarsal arteries: They take part in brevis. digitorum the formation of lateral and medial malleolar arte rial networks. " Arcuate artery: It arises near the base of DORSALIS PEDIS ARTERY (FIG. 28.16) metatarsal, and runs laterally with slighttheconvexity second It is the chief artery of the dorsum of the foot. towards the toes, to reach the lateral edge of the foot. It gives three dorsal metatarsal Origin (second, third, and fourth), each of whicharteries divides The dorsalis pedis artery is the direct continuation of the into two dorsal digital arteries for the lateral four toes. The lateral one sends a twig to the lateral side anterior tibial artery in front of the ankle. of the little toe. Anterior tibial artery -Dorsalis pedis artery Lateral tarsal artery Medial tarsal artery Arcuate artery Proximal perforating arteries -Firstdorsal interosseous muscle 2nd, 3rd, and 4th dorsal First dorsal metatarsal arteries metatarsal artery Distal perforating arteries -Dorsal digital artery to medial Dorsal digital arteries side of big toe artery of dorsalis pedis Course and branches FIG. 28.16  388 Textbook of Anatony: Abdomen and " First dorsal Lower Limb metatarsal artery: arises just before the dorsalis pedis artery dips It divides into dorsal digital into the sole of the foot. It 2GntseSniember sides of the first arteries for the sal digital artery and second toes. It also givesadjacent to the a dor " Chief muscle of the anterior Cormpartrment of the leg Tibialis anterior medial side of the big toe. Peroneus tertius Most recent muscle of the anterior compartment of the leg CLINICAL CORRELATION from evolutionary point of view Dorsalis pedis artery pulse: It can be easily felt of foot "Only intrinsic muscle on the Extensor digitorum between the tendons of extemsor ballucis on dorsum dorsum of the foot brevis tendon of extensor digitorum longus (Fig. longus and " All the muscles of the anterior Itis often palpated in patients 28.17). suffering from vaso-occusive compartrnent of the leg arise Tibialis anterior which diseases of the lower limb, namely from the fibula except arises from tibia The clinicians feeling this that the dorsalis pedis pulseBuerger' s disease. should know the fact -Nervus hesitans 14% of the cases. In such artery is congenitally absent in Deep peroneal nerve cases, the absence of dorsalis pedisabout " Cutaneous innervation of the pulse should be confirmed by the Cleft whole of the dorsum of the foot and between the first posterior tibial artery pulse. second toes which is from superficial peroneal is nerve except innervated by the deep peroneal nerve " Most superficial and strongest Tendon of extensor Tibialis anterior digitorum longus dorsiflexor of the foot Tendon of extensor hallucis longus Dorsalis pedis artery FIG. 28.17 Palpation of of dorsalis pedis artery). 'dorsalis pedis pulse' (pulse point CLINICAL CASE STUDY A Few27-year-old healthy days later, he was individual was recruited in the army. part of his training. In themade to run for a long distance as a ANSWERS 1. It is a clinical he felt severe pain in his night, when he was going to sleep, legs, which was ments. He was given a painkiller aggravated by move along the frontcondition characterized of the distal by pain and two-third of the leg. It swelling pain. Next day morning, he could by the doctor to relieve 2. described the as acting tight, is often taken to the army hospital where not dorsiflex his feet. He was Because of overexertion cramping or the squeezing pain. of his legs were the doctors found that both partment of the leg swell andmuscles of the anterior com noted foot drop onswollen and tender to andcompress both the sides. He was pressure. They also 3. artery leading toischaemia pain. the anterior tibial of 'anterior tibial compartment diagnosed as a case Because the anterior QUESTIONS syndrome. 4. unyielding bones andcompartment Deep is deep fascia. confined mostly by 1.What is 5. peroneal nerve and anterior tibial 2. What is meant Compression of the deep peroneal nerve.artery. by the the cause of anterior tibial compartment this syndrome? syndrome? 3. Why is the anterior this syndrome? compartment of the leg susceptible to 4. Name the nerve and artery rior compartment of the leg which within it. course within the ante and supply muscles present 5. Give the cause of foot drop in this syndrome.