Injury to the common peroneal nerve The common fibular nerve may be severed during fracture of the fibula neck. Results in paralysis of all muscles in the anterior and lateral compartments of the leg. The loss of eversion of the foot and dorsiflexion of the ankle causes foot- drop. Foot-drop: the foot drops and the toes drag of the floor when walking.
PNS Throughout Life Dermatome – an area of skin Innervated by cutaneous branches of a single spinal nerve Embryonic muscles migrate to new locations Some skin dermatomes become displaced Muscles and skin always retain their original nerve supply
Innervation of the Skin: Dermatomes Upper limb – skin is supplied by nerves of the brachial plexus Lower limb: Lumbar nerves – anterior surface Sacral nerves – posterior surface
Elsie (L.3 ) is trying to rescue her clumsy man Slim (SI) from a septic tank (SciaTIC nerve), using a rope and a balloon. He has some GLUe (nerves to GLUteus muscles) on his leg. She is pregnant· is FEMale (FEMoral nerve) and has an OBstetric condition (OBturator nerve).
Disc Level Root Comp. Weakness Reflex Involvement Sensory Loss Pain Distribution L3-L4 L4 quadriceps, tibialis anterior knee jerkmedial knee and shinanterior thigh L4-L5 L5 extension of big toe no significantbig toeback of thigh, lateral calf L5-S1 S1 gastrocnemius (ankle plantar flexion) Achilleslateral foot and heelback of thigh and calf
Lower limb dermatomes L1 Dermatome: over trochanter and groin L2 Dermatome: front of thigh to knee L3 Dermatome: upper buttock, anterior thigh and knee, medial lower leg L4 Dermatome: lateral Buttock, lateral thigh, medial leg, dorsum of foot, big toe L5 Dermatome: Buttock, posterior and lateral thigh, lateral aspect of leg, dorsum of foot, medial half of sole, first, second, and third toes S1 Dermatome: Buttock, thigh, and posterior leg S2 Dermatome: Buttock, thigh, and posterior leg S3 Dermatome: Groin, medial thigh to knee S4 Dermatome: Perineum, genitals, lower sacrum