Download TSM102 - Leg 2 and Foot Joints

TSM102: POSTERIOR LEG AND FOOT JOINTS
11/12/08
LEARNING OUTCOMES
Recognise the location and contents of the posterior compartment of the leg

The posterior compartment of the leg is the largest of the three and has superficial and deep layers:
o Superficial layer – all insert onto the calcaneus posteriorly (i.e. back of the heel)
 Gastrocnemius – most superficial and largest; two heads from femoral condyles
 Plantaris – small muscle belly from lateral femoral supracondylar line; long tendon
 Soleus – deepest; large and flat; from soleal line of tibia and fibular head
o Deep layer – proximally contains part of popliteus (see TSM97 - The Knee Joint)
 Flexor hallicus longus – most lateral; from mid-fibula to distal phalanx of 1st digit
 Flexor digitorum longus – from proximal tibia to distal phalanges of 2nd to 4th digits
 Tibialis posterior – deepest; from interosseous membrane to navicular tuberosity
o All of the posterior compartment muscles are supplied by the tibial nerve (branch of sciatic)
Explain the anatomical basis of inversion/eversion movements of the foot

Synovial joints between the tarsal bones facilitate inversion and eversion of the foot:
o Subtalar joint – between lateral talus and medial calcaneus
o Talocalcaneonavicular joint (TCN) – medially
 The spring ligament is broad and joins navicular to calcaneus beneath the talus
 The bifurcate ligament joins lateral calcaneus to navicular and cuboid