Lower Limb Peripheral Nerve Examination

Femoral nerve (L2,3,4)

motor: iliopsoas, test with hip flexion against resistance, 

           quadriceps, test with knee extension against resistance (also inspect for any wasting, check 

           knee jerk)

sensation: front of thigh, medial of leg and foot

usually caused by hematoma of illacus ( hemophilia or hip extension injuries)

Common peroneal nerve (lateral popliteal) L4,5,S1,2

motor: ant compartment (ant tibialis, extensor hallucis longus, extensor digitorum longus, peroneus tertius)

           peroneal compt (peroneus longus n brevis)

           foot ( extensor brevis)

test dorsiflexion (deep branch) and evertion (sup branch) of foot

sensation: first web of foot,dorsum of foot, front and side of leg

usually caused by if @ fibular neck, trauma (lateral ligament injury of knees or direct blow), pressure (cast/side iron of thomas splint; ganglion), ischemia ( tourniquet)

 if distal to fibular nerve, ant compartment syndrome

Tibial nerve (L4-S3)

motor: post comprt ( gastrocnemius, post tibialis, flexor hallucis longus, flexor digitorum longus)

           all the ms of sole via medial n lateral plantar n

inspect, ms wasting of sole, clawing of toe, trophic ulceration, test for power of toe flexion

sensation, sole of foot, dorsum of toe and nailbed

side of foot by sural nerve (tibial mix common peroneal)

proximal lesion of tibial nerve (wasting and loss of plantarflexion)

causes: proximal tibial fracture. post compartment syndrome, tight cast, diabetic neuropathy, tarsal tunnel syndrome

sciatic nerve (L4-S3)

motor loss: hamstring of thigh, tibial and peroneal nerve palsy

sensory loss: entire sole, foot, dorsum of foot, lateral aspect of leg, lateral half of calf, (if post cutaneous nerve of thigh is involved then back of thigh also lost sensation)

causes, usually post dislocation of hip, wound to post thigh (do not confused with sciatic palsy  2 to root involvement caused by PID)

absent ankle jerk

Lateral cutaneous n of thigh (L2,3)

maybe compressed by inguinal ligament (pain n parasthesia) or by spinal stenosis

sensory: lateral aspect of thigh

test, pressure over the nerve may give parasthesia to the thigh

neurological control of bladder, s2,3,4 supplies detrusor muscle of bladder and internal spincter

if cord transected above L2, thoracic spine fracture, voluntary control loss, still able to empty bladder 200-400ml every 2-4 hours, automatic bladder

if sacral centre damage or damage to cauda,  loss of reflex, atonic bladder