Anatomy of the Leg and Foot Anterior Leg Function: Nerve: Attachment: Artery: Anterior Leg Muscles Arteries/Nerves Anterior Leg/Dorsum Foot Arteries of anterior leg/dorsal foot 2 Anterior tibial artery (1) • Perforates interosseous membrane at inferior border of popliteus muscle • Runs between tibialis anterior/extensor hallucis longus with deep fibular nerve. • At ankle it becomes dorsalis pedis artery (5) • Posterior/anterior recurrent tibial arteries (2) from two sides of interosseous membrane to genicular anastomosis • Medial (3)/lateral (4) malleolar arteries • Dorsalis pedis artery: terminal branch 1 3 4 5 6 7 8 Dorsalis pedis artery (5) Runs lateral to extensor hallucis longus tendon, under extensor digitorum brevis, with deep fibular nerve • Lateral/medial tarsal arteries: at the tarsus they form tarsal rete • Arcuate artery (6) - runs at tarsometatarsal joints, anastomoses with lateral tarsal artery •Dorsal metatarsal arteries (7) for metatarsal bones • Dorsal digital arteries (8) for digits • Perforating branches between the metatarsal bones anastomose with plantar arterial system. Strongest one is the deep plantar branch between the 1st and 2nd metatarsus Lateral Leg Function: Nerve: Attachment: Artery: Lateral Compartment of Leg Sural and Superficial Fibular Nerves Common Fibular (Peroneal) Nerve Course • Runs along biceps femoris at lateral margin popliteal fossa • Winds around neck of fibula • Enters lateral compartment, pierces peroneus longus m., splits into superficial/deep fibular nn. Branches • Lateral cutaneous sural nerve - with medial cutaneous sural nerve forms sural nerve that runs with lesser saphenous vein on gastrocnemius, sural n. supplies back of lat. malleolus and gives the lateral foot. • Superficial fibular (peroneal) nerve – supplies motor to lateral compartment then cutaneous on dorsum of foot and lat/distal leg • Deep fibular (peroneal) nerve – supplies motor to anterior compartment and dorsum of foot then cutaneous at 1st interdigital cleft Common Fibular (Peroneal) Nerve Course • Runs along biceps femoris at lateral margin popliteal fossa • Winds around neck of fibula • Enters lateral compartment, pierces peroneus longus m., splits into superficial/deep fibular nn. Branches • Lateral cutaneous sural nerve - with medial cutaneous sural nerve forms sural nerve that runs with lesser saphenous vein on gastrocnemius, sural n. supplies back of lat. malleolus and gives the lateral foot. • Superficial fibular (peroneal) nerve – supplies motor to lateral compartment then cutaneous on dorsum of foot and lat/distal leg • Deep fibular (peroneal) nerve – supplies motor to anterior compartment and dorsum of foot then cutaneous at 1st interdigital cleft Muscles of dorsal foot Fascia of Dorsal Foot Thin layer of fascia, several parts are strengthened: At the ankle the deep fascia forms the superior (4) and inferior (5) extensor retinaculum for the tendons of the extensor muscles (1-3) At the lateral malleolus the deep fascia forms the superior (8) and inferior (9) peroneal retinacula for the tendon of the peroneus muscles (6,7) At the medial malleolus the deep fascia forms the flexor retinaculum (10) for the tendons of the deep flexor muscles (13-14) Posterior Leg Function: Nerve: Attachment: Artery: Popliteal Fossa Rhomboid space posterior to the knee Roof: popliteal fascia Floor: capsule of the knee joint, femur, popliteus muscle Popliteal Artery Continuation of femoral artery in popliteal fossa Extends from adductor hiatus to origin of anterior tibial artery (7) Located medial/deep to popliteal vein (3) and sciatic / tibial nerve (NeVA) 8 8 • Medial superior geniculate artery (1) to genicular anastomosis • Lateral superior geniculate artery (4) to genicular anastomosis • Median geniculate artery (5) supply the cruciate ligaments • Medial inferior geniculate artery (2) to genicular anastomosis • Lateral inferior geniculate artery (6) to genicular anastomosis • Sural arteries (8) – supply gastrocnemius, soleus, plantaris Posterior Leg Compartment: Superficial Layer Posterior Leg Compartment: Deep Layer Arteries/Nerves of Posterior Leg Arteries of Posterior Leg 2 Posterior tibial artery (9) • Terminal branch of popliteal artery (2) • Passes beneath tendinous arch of soleus, runs between superficial and deep compartments In distal leg, runs between tendons of flexor digitorum longus and flexor hallucis longus Turns under sustentaculum tali, covered by abductor hallucis to reach sole of foot as it bifurcates to med/lat plantar arteries • Peroneal artery (8) – covered by flexor hallucis longus. Gives terminal branches to the lateral malleolar (3) and calcaneal (4) retia • Branches to medial malleolar (5) and calcaneal (6) retia • Medial and lateral plantar arteries - terminal branches on the sole of foot 5 3 6 4 Tibial Nerve Course • • • • • • Runs in popliteal fossa lateral/superficial to popliteal vessels (NeVA!) Runs between heads of gastrocnemius m. Runs under tendinous arch of the soleus muscle Between flexor hallucis longus and flexor digitorum longus Turns around back of medial malleolus At plantar region, subdivides into medial and lateral plantar nerves Branches • Medial cutaneous sural nerve – with lateral cutaneous sural nerve, forms sural nerve that runs with lesser (small) saphenous vein on gastrocnemius, supplies cutaneous innervation to lateral side of foot. • Motor branches – to posterior compartment of leg • Medial and lateral plantar nerves – covered by the plantar aponeurosis, supply the muscles and skin of the sole Crural Fascia Continuation of the fascia lata of the thigh Anterior (4) and posterior (5) crural intermuscular septa encloses the peroneus muscles Deep crural fascia (8) separates the superficial and deep flexors At the ankle the crural fascia forms the superior (2) and inferior (3) extensor retinaculum Continuous with the fascia of the dorsum of the foot (9) Plantar Foot Anatomy Plantar Fascia/Plantar Aponeurosis Superficial fascia: Thin fibrous layer on the dorsum Thick layer on the sole: fibrous septa and fat tissue between Deep fascia: Continuation of the crural fascia. In the dorsum of the foot it is a thin layer covering the muscles. In the plantar region it is thickened, forming the plantar aponeurosis (1) that is composed of superficial longitudinal fibers (2) and deep transverse fibers (3). Medial and lateral plantar septa extend to the tarsal and metatarsal bones separating the medial, median and lateral plantar eminences Sole Foot: 1st layer muscles Sole Foot: 2nd layer muscles Sole Foot: 3rd layer muscles Sole Foot: 4th layer muscles Sole Foot: Arteries Sole Foot: Nerves Veins of Lower Limb Superficial (subcutaneous) venous circulation: Great saphenous vein Medial side of the lower limb, enters into the femoral vein through the saphenous hiatus Dorsal venous network of the foot Small saphenous vein Lateral side of the foot, turns around the lateral malleolus posteriorly. On the leg it runs between the medial and lateral gatrocnemius entering into the popliteal vein at the popliteal fossa Deep venous circulation: Vena comitantes accompany the branches of deep arteries