1. POSTERIOR COMPARTMENT (1) Muscles : (1) Muscles : Divided by the Deep transverse fascia of the leg into : Divided by the Deep transverse fascia of the leg into : A. Superficial group. A. Superficial group. B. Deep group. B. Deep group. (2) Vessels : Posterior tibial artery. (2) Vessels : Posterior tibial artery. (3) Nerves : Tibial nerve. (3) Nerves : Tibial nerve.

2. CUTANEOUS NERVES 1. Posterior cutaneous nerve of the thigh. 1. Posterior cutaneous nerve of the thigh. It supplies the skin over the popliteal fossa and the upper part of the back. It supplies the skin over the popliteal fossa and the upper part of the back. 2. Lateral cutaneous nerve of the calf (common peroneal) to the upper part of postero- lateral surface of the leg. 2. Lateral cutaneous nerve of the calf (common peroneal) to the upper part of postero- lateral surface of the leg.

3. CUTANEOUS NERVES 3. Sural nerve (tibial). 3. Sural nerve (tibial). To the lower part of the postero lateral surface of the leg. To the lower part of the postero lateral surface of the leg. 4. Saphenous nerve (femoral ). 4. Saphenous nerve (femoral ). To the posteromedial surface. To the posteromedial surface.

4. SUPERFICIAL MUSCLES 1. Gastrocnemius (lateral and medial heads). 1. Gastrocnemius (lateral and medial heads). 2. Soleus. 2. Soleus. 3. Plantaris. 3. Plantaris.

5. PLANTARIS Origin : Lateral supracondylar ridge of the femur.

6. SOLEUS Has an inverted V shaped Origin : Has an inverted V shaped Origin : (1) Soleal line on the posterior surface of tibia. (1) Soleal line on the posterior surface of tibia. (2) Upper ¼ of posterior surface of the shaft of the fibula. (2) Upper ¼ of posterior surface of the shaft of the fibula. (3) Fibrous arch between the two bones. (3) Fibrous arch between the two bones.

7. GASTROCNEMIUS It is the most superficial of the calf muscles. Lateral Head : lateral aspect of the lateral condyle of the femur. Medial Head : popliteal surface of the femur above the medial femoral condyle.

8. TENDO CALCANEUS It is the common tendon of Insertion. It is the common tendon of Insertion. It is attached to the posterior surface of the calcaneum. It is attached to the posterior surface of the calcaneum. The two bellies of Gastrocnemius join its posterior part. The two bellies of Gastrocnemius join its posterior part.

9. TENDO CALCANEUS The tendon of Soleus joins its anterior part. The tendon of Soleus joins its anterior part. The Plantaris is inserted into the posterior surface of the calcaneum medial to the tendo calcaneus. The Plantaris is inserted into the posterior surface of the calcaneum medial to the tendo calcaneus.

10. Soleus : Soleus : It is the strongest plantar flexor of the ankle. It is the strongest plantar flexor of the ankle. when this plantar flexion has to be done with power, it needs the help of gastrocnemius. when this plantar flexion has to be done with power, it needs the help of gastrocnemius. Both Gastrocnemius and Soleus are active in walking and running during the take off stage of the foot. Both Gastrocnemius and Soleus are active in walking and running during the take off stage of the foot. ACTION

11. ACTION Gastrocnemius : Gastrocnemius : It plantar flexes the ankle. It can flex the knee (not at the same time). It plantar flexes the ankle. It can flex the knee (not at the same time). In rising on the tips of the toes the Soleus and the Gastrocnemius lift the weight of the whole body because in this case the knee is extended. In rising on the tips of the toes the Soleus and the Gastrocnemius lift the weight of the whole body because in this case the knee is extended.

12. REPTURE OF TENDOCALCANEUS It is most common in middle aged males (tennis players). It is most common in middle aged males (tennis players). It is reptured in its narrowest site (5 cm) above its insertion. It is reptured in its narrowest site (5 cm) above its insertion. Symptoms : Symptoms : Sudden sharp pain. Sudden sharp pain.

13. REPTURE OF TENDOCALCANEUS Signs : Signs : Palpable gap in the tendon. Palpable gap in the tendon. Inability to active planter flexion of the foot. Inability to active planter flexion of the foot. Management: Management: Immediate suturing of the tendon. Immediate suturing of the tendon. The leg is immobilized with planter flexion of the ankle joint and flexion of the knee. The leg is immobilized with planter flexion of the ankle joint and flexion of the knee.

14. DEEP GROUP OF MUSCLES 1. Popliteus. 1. Popliteus. 2. Flexor digitorum longus. 2. Flexor digitorum longus. 3. Flexor hallucis longus. 3. Flexor hallucis longus. 4. Tibialis posterior. 4. Tibialis posterior.

15. Flexor Digitorum Longus Origin : Origin : Medial part of the posterior surface of the tibia below soleal line. Medial part of the posterior surface of the tibia below soleal line.

16. Flexor Digitorum Longus Insertion Insertion the main tendon is divided into four to the lateral four toes. They are inserted into the bases of the distal phalanges of the corresponding toes. The main tendon gives insertion to the quadratus plantae and origin to the four lumbricals.

17. Flexor Digitorum Longus Action Action (1) Flexion of the distal phalanges of the lateral four toes. (1) Flexion of the distal phalanges of the lateral four toes. (2) Plantar flexion and inversion of the foot. (2) Plantar flexion and inversion of the foot. (3) Maintains medial longitudinal arch. (3) Maintains medial longitudinal arch.

18. Flexor Hallucis Longus Origin Origin Lower 2/3 of the posterior surface of the shaft of the fibula. Lower 2/3 of the posterior surface of the shaft of the fibula.

19. Flexor Hallucis Longus Insertion Insertion Base of the terminal phalanx of the big toe. Base of the terminal phalanx of the big toe. It passes beneath the Sustentaculum tali. It passes beneath the Sustentaculum tali. It gives off a strong slip to the tendon of flexor digitorum longus. It gives off a strong slip to the tendon of flexor digitorum longus.

20. Flexor Hallucis Longus Action : Action : (1) Flexion of the distal phalanx of the big toe. (1) Flexion of the distal phalanx of the big toe. (2) Plantar flexion and inversion of the foot. (2) Plantar flexion and inversion of the foot. (3) Maintains medial lonigtudinal arch. (3) Maintains medial lonigtudinal arch.

21. Tibialis Posterior Origin Origin (1) Lateral part of the posterior surface of the tibia. (1) Lateral part of the posterior surface of the tibia. (2) Interosseous membrane. (2) Interosseous membrane. (3) Upper ½ of the posterior surface of the shaft of the fibula. (3) Upper ½ of the posterior surface of the shaft of the fibula.

22. Tibialis Posterior Insertion Insertion The main insertion is into the Tuberosity of navicular bone and medial cuneiform. The main insertion is into the Tuberosity of navicular bone and medial cuneiform. Small slips are inserted into every bone in the tarsus Except the talus. Small slips are inserted into every bone in the tarsus Except the talus.

23. Tibialis Posterior Action Action (1) Plantar flexion and inversion of the foot. (1) Plantar flexion and inversion of the foot. (2) Maintains medial lonigtudinal arch. (2) Maintains medial lonigtudinal arch.

24. POSTERIOR TIBIAL ARTERY Origin : Origin : One of the two terminal branches of the popliteal artery. One of the two terminal branches of the popliteal artery. It begins at the lower border of the popliteus muscle. It begins at the lower border of the popliteus muscle.

25. COURSE It is very deep at its origin. It is very deep at its origin. It passes under cover of the tendinous arch of the soleus and the gastrocnemius. It passes under cover of the tendinous arch of the soleus and the gastrocnemius. In the lower part of the leg it becomes superficial (covered by skin and fascia only). In the lower part of the leg it becomes superficial (covered by skin and fascia only).

26. COURSE It runs downwards lying successively on : It runs downwards lying successively on : 1. Tibialis posterior. 1. Tibialis posterior. 2. Flexor digitorum longus. 2. Flexor digitorum longus. 3. Posterior surface of the Tibia 3. Posterior surface of the Tibia 4. Back of the ankle joint. 4. Back of the ankle joint.

27. COURSE It passes behind the medial malleolus deep to the flexor retinaculum where it divides into its two terminal branches. It passes behind the medial malleolus deep to the flexor retinaculum where it divides into its two terminal branches.

28. PULSE Can be felt as it lies between the tendons of flexor digitorum longus and flexor hallucius longus. Can be felt as it lies between the tendons of flexor digitorum longus and flexor hallucius longus. Midway between the medial malleolus and the heel. Midway between the medial malleolus and the heel.

29. TERMINAl BRANCHES It divides into Medial and Lateral plantar arteries beneath the flexor retinaculum. They are the main arterial supply to the sole of the foot. It divides into Medial and Lateral plantar arteries beneath the flexor retinaculum. They are the main arterial supply to the sole of the foot.

30. BRANCHES (1) peroneal artery (1) peroneal artery It is the largest and most important branch. It is the largest and most important branch. It arises from the posterior tibial artery a short distance below its origin. It arises from the posterior tibial artery a short distance below its origin. It passes obliquely downwards and laterally to the fibula. It passes obliquely downwards and laterally to the fibula.

31. BRANCHES (2) Muscular branches. (2) Muscular branches. (3) Nutrient artery to the tibia. (3) Nutrient artery to the tibia. (4) Anastomotic branches around the medial malleolus. (4) Anastomotic branches around the medial malleolus. (5) Medial and Lateral plantar arteries. (5) Medial and Lateral plantar arteries.

32. PERONEAL ARTERY It gives : It gives : A. Perforating artery in the lower part of the front of the leg. A. Perforating artery in the lower part of the front of the leg. B. Muscular branches. B. Muscular branches. C. Nutrient artery to the fibula. C. Nutrient artery to the fibula. The peroneal artery ends by giving branches that share in the anastomosis around the lateral malleolus. The peroneal artery ends by giving branches that share in the anastomosis around the lateral malleolus.

33. POSTERIOR TIBIAL NERVE It Begins at the lower border of the popliteus muscle as a continuation of the tibial nerve. It Begins at the lower border of the popliteus muscle as a continuation of the tibial nerve. It Ends under the flexor retinaculum by dividing into medial and lateral plantar nerves. It Ends under the flexor retinaculum by dividing into medial and lateral plantar nerves.

34. COURSE It passes down between the flexor digitorum longus and the flexor hallucis longus on the surface of tibialis posterior It passes down between the flexor digitorum longus and the flexor hallucis longus on the surface of tibialis posterior It is covered by the soleus and gastrocnemius. It is covered by the soleus and gastrocnemius.

35. COURSE In the lower part of the leg it lies on the posterior surface of the tibia and is only covered by skin and fascia. In the lower part of the leg it lies on the posterior surface of the tibia and is only covered by skin and fascia.

36. RELATION WITH POSTERIOR TIBIAL ARTERY It has a Triple relation with the posterior tibial artery : It has a Triple relation with the posterior tibial artery : At first the nerve is Medial to the artery. At first the nerve is Medial to the artery. It crosses posterior to the artery. It crosses posterior to the artery. It descends on the Lateral side of the artery It descends on the Lateral side of the artery

37. BRANCHES (1) Muscular (below popliteal fossa) to (four) muscles : (1) Muscular (below popliteal fossa) to (four) muscles : Soleus, tibialis posterior, flexor digitorum longus and flexor hallucis longus. Soleus, tibialis posterior, flexor digitorum longus and flexor hallucis longus. (2) Cutaneous : (2) Cutaneous : Medial calcaneal branch to the medial side of the heel. Medial calcaneal branch to the medial side of the heel. (3) Articular : to the ankle joint. (3) Articular : to the ankle joint. (4) Medial and lateral plantar nerves. (4) Medial and lateral plantar nerves.

38. RETINACULA They are thickening of the deep fascia in the region of the ankle. They are thickening of the deep fascia in the region of the ankle. They lie across the long tendons in the lower leg and in front of the ankle joint. They lie across the long tendons in the lower leg and in front of the ankle joint. They keep the tendons in position and serve as modified pulleys. They keep the tendons in position and serve as modified pulleys.

39. SUPERIOR EXTENSOR RETINACULUM It is about(3) cm wide. It is about(3) cm wide. It is stretched between the distal ends of the anterior borders of the tibia and fibula. It is stretched between the distal ends of the anterior borders of the tibia and fibula. It splits to enclose the tendon of tibialis anterior. It splits to enclose the tendon of tibialis anterior. It extends over the Extensor tendons, Anterior Tibial vessels and the Deep Proneal nerve. It extends over the Extensor tendons, Anterior Tibial vessels and the Deep Proneal nerve.

40. INFERIOR EXTENSOR RETINACULUM It is thicker and (Y) shaped. It extends medially from the upper surface of the calcaneus and then splitting into two parts in front of the ankle joint. The upper part is attached to the medial malleolus. The lower blends with the plantar fascia. Fibrous bands separate the tendons into compartments. Each has its own synovial sheath.

41. SUPERIOR PERONEAL RETINACULUM It extends downwards and backwards from the lateral malleolus to the lateral surface of the calcaneum. It binds the tendons of peronei longus and brevis to the lateral side of the ankle. The tendons have a common synovial sheath

42. INFERIOR PERONEAL RETINACULUM It is attached to the peroneal tubercle and to the calcaneum above and below the peroneal tendons. It is attached to the peroneal tubercle and to the calcaneum above and below the peroneal tendons. Each peroneal muscle has its own synovial sheath which is continuous above with the common sheath. Each peroneal muscle has its own synovial sheath which is continuous above with the common sheath.

43. FLEXOR RETINACULUM It is attached between the medial malleolus and the medial surface of the calcaneum. It is attached between the medial malleolus and the medial surface of the calcaneum. It holds and protects the structures which pass behind the medial malleolus( tendons of the Deep flexor Muscles, Posterior tibial Nerve and Posterior tibial Vessels) to enter the sole. It holds and protects the structures which pass behind the medial malleolus( tendons of the Deep flexor Muscles, Posterior tibial Nerve and Posterior tibial Vessels) to enter the sole.