Chapter 6: Lower Limb: Hip, Thigh, Leg & Foot Anatomy

Lower Limb: Hip, Thigh, Leg & Foot Anatomy begins by establishing the structural framework of the limb, detailing the osteology of the pelvic girdle, femur, patella, tibia, fibula, and the complex arrangement of tarsals, metatarsals, and phalanges in the foot. The text examines the major articulations, including the multiaxial ball-and-socket hip joint, the complex hinge mechanism of the knee with its stabilizing menisci and cruciate ligaments, and the talocrural ankle joint. Significant attention is given to the fascial compartmentalization of the limb, dividing muscles into functional groups: the gluteal region’s extensors and rotators; the thigh’s anterior quadriceps, medial adductors, and posterior hamstrings; and the leg’s compartments responsible for ankle dorsiflexion, eversion, and plantarflexion. The chapter highlights critical transition zones—such as the femoral triangle, adductor canal, popliteal fossa, and tarsal tunnel—that serve as conduits for the neurovascular bundles. The innervation patterns arising from the lumbosacral plexus are traced, specifically the courses of the femoral, obturator, and sciatic nerves, along with their terminal branches like the tibial and common fibular nerves. Vascular anatomy is mapped from the external iliac vessels through the femoral, popliteal, and tibial arteries to the plantar arches, alongside the superficial and deep venous drainage systems. Biomechanical concepts, including the locking mechanism of the knee and the dynamic support of the longitudinal and transverse foot arches, are explained in relation to gait and stance. Finally, the chapter integrates extensive clinical correlations, addressing pathologies such as femoral neck and pelvic fractures, compartment syndrome, varicose veins, deep vein thrombosis, ligamentous ruptures (ACL/MCL), meniscal tears, and peripheral nerve entrapments leading to conditions like footdrop.