WINDSOR UNIVERSITY SCHOOL OF MEDICINE

1. WINDSOR UNIVERSITYSCHOOL OF MEDICINE DEPARTMENT OF ANATOMY Lower limb LEG Dr. SREEKANTH THOTA

2. Fascial Compartments of the Leg • The leg is that part of the lower limb between the knee joint and ankle joint . • The leg is divided into anterior , posterior , and lateral (fibular) compartments by: • 1. An interosseous membrane, which links adjacent borders of the tibia and fibula along most of their length. • 2. Two intermuscular septa, which pass between the fibula and deep fascia surrounding the limb.

4. Compartments of leg • 1. Muscles in the anterior compartment of leg dorsiflex the ankle, extend the toes, and invert the foot. • 2. Muscles in the posterior compartment plantarflexthe ankle, flex the toes, and invert the foot. • 3. Muscles in the lateral compartment evert the foot.

5. Retinacula of the Ankle • 1. Extensor retinacula :Two extensor retinacula strap the tendons of the extensor muscles to the ankle region and prevent tendon bowing during extension of the foot and toes . • 1. Superior extensor retinaculum • 2. Inferior extensor retinaculum: Y-shaped

6. Fibular retinacula • Fibular (peroneal) retinacula bind the tendons of the fibularislongus and fibularisbrevismuscles to the lateral side of the foot. • 1. Superior fibular retinaculum • 2. Inferior fibular retinaculum

7. Flexor retinaculum • It attaches above to the medial malleolus and below and behind to the inferomedial margin of the calcaneus.

8. Anterior compartment of leg • Muscles: The tibialis anterior, extensor digitorumlongus, Fibularistertius, and extensor hallucislongus • Blood supply: Anterior tibial artery • Nerve supply: Deep peroneal nerve • Action:Dorsiflex the foot at the ankle joint, extend the toes, and invert the foot.

9. Tibialis anterior • Origin: Lateral surface of shaft of tibia and interosseous membrane • Insertion :Medial cuneiform and base of first metatarsal bone • N. supply: Deep peroneal nerve • Action:Dorsiflexion of foot at ankle joint; inversion of foot.

10. Extensor digitorumlongus • Origin: Anterior surface of shaft of fibula • Insertion :Extensor expansion of lateral four toes • N. supply: Deep peroneal nerve • Action:Extension of lateral four toes and dorsiflexion of foot

11. Extensor hallucislongus • Origin: Anterior surface of shaft of fibula • Insertion :Base of distal phalanx of great toe • N. supply: Deep peroneal nerve • Action:Extension of great toe and dorsiflexion of foot

12. Fibularistertius • Origin: Anterior surface of shaft of fibula • Insertion :Base of fifth metatarsal bone • N. supply: Deep peroneal nerve • Action:Dorsiflexion and eversion of foot

13. Artery of the Anterior Compartment of the Leg • Anterior Tibial Artery: Terminal branch of the popliteal artery. • It arises at the level of the lower border of the popliteus muscle and passes forward into the anterior compartment of the leg through an opening in the upper part of the interosseous membrane.

14. Pulse of anterior tibial artery • Having passed behind the superior extensor retinaculum, it has the tendon of the extensor hallucislongus on its medial side and the deep peroneal nerve and the tendons of extensor digitorumlongus on its lateral side. • In front of the ankle joint, the artery becomes the dorsalispedis artery.

15. Nerve Supply of the Anterior Compartment of the Leg • Deep Peroneal Nerve: Terminal branch of the common peroneal nerve . • Branches • 1. Muscular branches :Tibialis anterior, the extensor digitorumlongus, the peroneustertius, and the extensor hallucislongus. • 2. Articular branch to the ankle joint

16. Injury to common fibular nerve • Footdrop and loss of eversion • May cause sensory loss over lateral leg and dorsum of foot • Causes • Direct trauma as nerve passes superficially around neck of fibula

17. Foot drop • Foot drop, sometimes called drop foot, is a general term for difficulty lifting the front part of the foot. • The loss of dorsiflexion of the ankle causes footdrop.

18. Lateral Compartment of the Leg • Muscles: Fibularislongus and Fibularisbrevis • Blood supply: Branches from the Fibular artery • Nerve supply: Superficial peroneal nerve

19. Fibularislongus • Origin: Lateral surface of shaft of fibula • Insertion :Base of first metatarsal and the medial cuneiform • N. supply: Superficial fibular nerve • Action:Eversion of foot

20. Fibularisbrevis • Origin: Lower two-thirds of lateral surface of shaft of fibula • Insertion :Base of fifth metatarsal bone • N. supply: Superficial Fibular nerve • Action:Eversion of foot

21. Artery of the Lateral Compartment of the Leg • Numerous branches from the fibular artery which lies in the posterior compartment of the leg, pierce the posterior fascial septum and supply the Fibularis muscles.

22. Nerve of the Lateral Compartment of the Leg • Superficial Fibular Nerve: The superficial fibular nerve is one of the terminal branches of the common fibular nerve. • It arises in the substance of the Fibularislongus muscle on the lateral side of the neck of the fibula. • Branches • Muscular branches : Fibularislongus and brevis

23. Injury to superficial fibular nerve • Loss of eversion • Fibularislongus and brevis

24. Posterior compartment of leg • Muscles in the posterior (flexor) compartment of leg are organized into two groups, superficial and deep. • Blood supply: Posterior tibial artery. • Nerve supply: Tibial nerve

25. Muscles of the Posterior Compartment of the Leg Superficial group of muscles • 1.Gastrocnemius • 2.Soleus • 3.Plantaris Deep group of muscles • 1.Popliteus • 2.Tibialis posterior • 3.Flexor digitorumlongus • 4.Flexor hallucislongus Muscles mainly plantarflex,invertthe foot and flex the toes.

26. Superficial group • Gastrocnemius • Soleus • Plantaris Gastrocnemius and plantaris cross knee joint and thus also flex knee . All three contribute to calcaneal tendon.

28. Gastrocnemius • Origin: Lateral head from lateral condyle of femur Medial head from above medial condyle • Insertion:Via tendo calcaneus into posterior surface of calcaneum • Innervation: Tibial nerve • Function: Plantarflexes foot and flexes knee

29. Plantaris • Origin: Lateral supracondylar ridge of femur • Insertion: Posterior surface of calcaneum • Innervation: Tibial nerve • Function: Plantarflexes foot and flexes knee

30. Soleus • Origin: Shafts of tibia and fibula • Insertion: Posterior surface of calcaneum • Innervation: Tibial nerve • Function: Plantarflexes the foot

31. Deep group of muscles • Popliteus • Origin: Lateral surface of lateral condyle of femur • Insertion: Posterior surface of shaft of tibia above soleal line • Innervation: Tibial nerve • Function: Flexes leg at knee joint • “Unlock the knee” popliteuscontracts rotating the femur laterallyso that flexion of the knee can occur

32. Flexor digitorumlongus • Origin: Posterior surface of shaft of tibia • Insertion: Bases of distal phalanges of lateral four toes • Innervation: Tibial nerve • Function: Flexes distal phalanges of lateral four toes; plantar flexes foot at ankle joint

33. Flexor hallucislongus • Origin: Posterior surface of shaft of fibula • Insertion: Base of distal phalanx of big toe • Innervation: Tibial nerve • Function: Flexes distal phalanx of big toe; plantar flexes foot at ankle joint

34. Tibialis posterior • Origin: Posterior surface of shafts of tibia and fibula and interosseous membrane • Insertion: Tuberosity of navicular bone • Innervation: Tibial nerve • Function: Inversion and plantarflexion of foot

36. Nerve supply Tibial nerve: Supplies all muscles in posterior compartment. Divides into medial and lateral plantar nerves inferior and posterior to medial malleolus.

38. Blood supply: Posterior tibial artery: Largest branch of popliteal artery. Divides into medial and lateral plantar arteries. Fibular artery: Most important branch of posterior tibial artery. Supplies lateral compartment.

39. Arteries in the posterior compartment of leg.

40. Tarsal tunnel The 'tarsal tunnel' is formed on the posteromedial side of the ankle by a depression formed by the medial malleolus of the tibia, the medial and posterior surfaces of the talus, the medial surface of the calcaneus and overlying flexor retinaculum.

42. Contents of Tarsal tunnel Structures That Pass Behind the Medial Malleolus Beneath the Flexor Retinaculum From Medial to Lateral 1.Tibialis posterior tendon 2.Flexor digitorumlongus 3.Posterior tibial artery 4.Tibial nerve 5.Flexor hallucislongus ( TOM DICK AND HARRY)

43. Tibial Nerve Entrapment • Tarsal tunnel syndrome • Tarsal tunnel syndrome is caused by compression of the tibial nerve in the canal formed by the flexor retinaculum and the foot bones. • Causes: • 1. Tenosynovitis (swelling of the synovial membrane lining the tendons) • 2. Fractures of the talus, tibia or calcaneum bones • Symptoms • Abnormal sensation such as tingling and numbness in the sole or toes • Treatmentnon-operative and operative. • .

44. Posterior Tibial Pulse The posterior tibial pulse can usually be palpated between the posterior surface of the medial malleolus and the medial border of the calcaneal tendon.