Nerves in different distribution stages of the spinal cord control each joint of the lower limb. Hip flexion (iliopsoas) is controlled by L2 and L3, and hip extension (gluteus maximus and sK muscles) by L4 and L5. Knee extension and mat reflex (quadriceps) were controlled by L3 and L4, and knee flexion (sK muscle) by L5 and S1. Dorsiflexion of the talocrural joint (tibialis anterior and extensor digitorum longus) was controlled by L4 and L5, and flexion of the calcaneus (muscles of the calf’s belly) was controlled by S1 and S2 nerves. Foot inversion is controlled by L4 and foot eversion by L5 and S1. Lateral aspect of the foot: S1 usually involves disc pathology from L5 to S1, L5 affects from the middle portion of the foot near S1 to the lateral calf, L4 innervates the medial aspect, and L2 and L3 occupy the thigh. “Standing at S1, kneeling at L3, sitting at S3” The femoral nerve then innervates the iliopsoas muscle above the inguinal ligament, and then below the inguinal ligament, innervates the quadriceps, suture muscles, and pubococcygeus muscle. Below the inguinal ligament, the femoral nerve is responsible for sensation in the anterior aspect of the thigh, while the femoral nerve endings tap the medial aspect of the calf and foot. Injury to the femoral nerve can occur in iliopsoas muscle hematomas, resulting in elevated local pressure, commonly seen in hemophilia and hip strain injuries. Examination of the femoral nerve: the patient is instructed to test the quadriceps by performing a knee extension against resistance. Ask the patient to test the iliopsoas muscle by flexing the hip against resistance. Distribution of common peroneal nerve: tibialis anterior, extensor digitorum longus, extensor digitorum longus, peroneus brevis, peroneus longus shortus, extensor digitorum longus. Sensory nerve distribution of the common peroneal nerve: surface of the web of the first toe, dorsum of the foot and anterior and lateral part of the calf. Common peroneal nerve susceptibility to injury: peroneal neck, distal peroneal neck Common peroneal nerve injury Section presents with foot drop, gait abnormalities where the lower leg must be elevated to achieve landing of the plantarflexed foot, or the feet glide across the ground, resulting in rapid and significant sole wear on one side. Examination of the common peroneal nerve: the patient is instructed to dorsiflex the foot, or to pronate the foot. Motor nerve distribution of the common peroneal nerve: flounder, tibialis posterior, bunion, phalanges, and all plantar muscles. Sensory nerve distribution of the tibial nerve: lateral plantar nerve innervates the sole of the foot Tibial nerve injury-prone areas: tibia, gastrocnemius muscle, inner ankle, foot. Tibial nerve examination: foot flexor strength. Tibial nerve examination: plantarflexion strength test. Sciatic motor nerve exam Sciatic sensory nerve exam: entire plantar, dorsal foot, calf, and lateral gastrocnemius Sciatic nerve vulnerable sites: posterior y, deep thigh Sciatic nerve exam: extensive disuse muscular dystrophy Lateral femoral cutaneous nerve exam Lateral femoral cutaneous nerve exam