Muscles of posterior compartment of leg

  Origin Insertion Action NS Gastrocnemius Med head: above med femoral condyle Lat head: lat femoral condyle tendocalcaneus 15 cm Strongest tendon in the body Inserted in calcaneus (middle 1/3) separated from it by bursa  Plantar flexion Elevation of heel during walking Flexion knee Tibial N Soleus Head and upper 1/3 of shaft of fibula (post surface) tendinous arch (between fibula & tibia) Soleal line med border of tibia (middle 1/3) Antigravity muscle Plantaris lat supracondylar line of femur

Popliteus lat femoral condyle post surface of tibia (above soleal line) Unlocking of knee (lat rotation of femur or med rotation of tibia) Flexion knee   Tibialis post post surface of tibia (lat part) post surface of fibula (med part) Post surface of interosseous membrane All tarsals except talus Middle 3 metatarsals Plantar flexion Inversion Flexor digitorum longus post surface of tibia (med part) Terminal phalanges of lat 4 toes Flexion of lat 4 toes (all joints) Flexor hallucis longus post surface of fibula (lat part) Terminal phalynx of big toe Flexion of big toe (all joints)

Muscles of posterior compartment of leg

Tibial nerve

Tibial nerve Root value: Sacral plexus, L4,5,S1,2,3 (ant rami, ant divisions). Beginning: one of 2 terminal branches of sciatic N, at the lower 1/3 of back of thigh (sup angle of popliteal fossa). Course & relation: It could be divided into 2 parts; med popliteal (in the popliteal fossa) & post tibial (in the back of leg). In popliteal fossa (med popliteal N): It enters through the sup angle (covered by biceps). It bisects the fossa as the most superficial structure. Leaves the fossa through the inf angle.

In the back of leg (post tibial N): Descends between soleus (superficial) & tibialis post (deep). It becomes subcutaneous on the post surface of tibia. Branches: In popliteal fossa (med popliteal N): Muscular: gastrocnemius, plantaris, soleus & popliteus. Cutaneous: Sural N: Joined by sural communicating N. Supplies lat side of foot & little toe. Articular: knee. Muscular: soleus, flexor digitorum longus, flexor hallucis longus & tibialis posterior. Med calcanean nerves supply skin of the heel. Articular: ankle. End: deep to flexor retinaculum by dividing into med & lat plantar Ns.

muscles of the Sole of foot   N.B: adduction & abduction on of toes is along a line of the 2nd toe.

Layer Muscle Action NS 1st Abductor hallucis Abduction of big toe Med Plantar N: supplies Flexor digitorum brevis 1st lumbrical Flexor hallucis brevis Lat plantar N: supplies other short Ms Abductor digitiminimi Abduction of little toe Flexion of lat 4 toes 2nd Flexor digitorum accessories Modify the angle of flexor digitorum longus 4 lumbricals Flexion of metatarsophalyngeal joint Extension of interphalyngeal joint Tendon of flexor digitorum longus Tendon of flexor hallucis longus 3rd Flexion of big toe Flexor digitiminimi Flexion of little toe Adductor hallucis Adduction of big toe 4th 3 plantar interossei Adduction of lat 3 toes 4 dorsal interossei Abduction of middle 3 toes Tendon of peroneus longus Tendon of tibialis post

N.B.: adduction & abduction of toes is along a line of the 2nd toe.