The lumbar plexus is located on the deep surface of the psoas major muscle in the posterior abdominal wall and consists of a portion of the anterior branch of the 12th thoracic nerve and the anterior branches of the 1st-4th lumbar nerves. The main nerves emanating from it to the lower extremities are the lateral femoral cutaneous nerve, the femoral nerve and the foramen ovale nerve, with branches innervating the anterior femoral group muscle, the medial femoral group muscle, the anterior medial femoral skin, the medial side of the calf and the medial edge of the foot. Injury to the lumbar nerve results in paralysis of the anterior femoral group of muscles, leading to weakness in hip flexion, inability to extend the knee and jump, and sensory deficits in the anterior thigh and the medial side of the calf and medial edge of the foot. The sacral plexus is located in the lateral wall of the pelvis and consists of a portion of the anterior branch of the 4th lumbar nerve and the anterior branch of the 5th lumbar nerve, which forms the lumbosacral trunk and the anterior branch of the sacral nerve. The nerves emanating from it to the lower limbs mainly include the superior gluteal nerve, the inferior gluteal nerve, the pubic nerve, the posterior femoral cutaneous nerve and the sciatic nerve. It distributes to the skin of the lower buttocks, the posterior femoral group of muscles, the calf muscles and the foot muscles, the skin of the posterior femur, the N, the posterior and anterolateral aspects of the calf and the foot (except for the medial edge of the foot). The sciatic nerve consists of the tibial and common peroneal nerves, which originate from the anterior and posterior femurs of the lumbar 4 and 5 and sacrum 1-3, respectively, enclosed in a connective tissue sheath. It passes through the inferior foramen of the pyriform muscle to the gluteal region, descends on the deep surface of the gluteus maximus along the midpoint of the greater trochanter and sciatic tuberosity, and travels posteriorly between the biceps femoris muscle and the semimembranosus muscle to the tip of the cystic fossa where it divides into the tibial and common peroneal nerves, branching along the way to innervate the posterior femoral biceps, semitendinosus and semimembranosus muscles. The performance after the injury depends on the plane of injury. Posterior hip dislocation, hip knife injury, hip muscle contracture surgical injury and hip muscle injection drugs can cause high level injury, causing paralysis of the posterior femoral muscles and all muscles of the calf and foot, resulting in inability to flex the knee joint, complete loss of ankle and toe motor function, and foot drop. There is loss of sensation in the posterior lateral calf and foot, and neurotrophic changes in the foot. The tibial nerve branches innervate the posterior calf group and plantar muscles, and the skin of the posterior calf, plantar, and lateral margin of the little toe. When the tibial nerve is injured, the posterior group of calf muscles and plantar muscles are paralyzed, resulting in inability to plantar flex the foot, significantly reduced inversion force, supination deformity with valgus, and inability to stand on the toes; the sensory loss area is mainly found on the sole of the foot. The common peroneal nerve can be divided into the deep peroneal nerve and the superficial peroneal nerve, of which the deep peroneal nerve is mainly the muscular branch, which innervates the anterior group of calf muscles and the dorsalis pedis muscle, and the dermal branch is only distributed at the opposite edge of the first toe web; the superficial peroneal nerve is mainly the dermal branch, which is distributed on the anterolateral side of the calf, the dorsalis pedis and the skin of the toes (except for the small area distributed by the deep peroneal nerve, the dorsal side between the 1 and 2 toe webs), and the muscular branch only innervates the long and short peroneal muscles (including the third peroneal muscle). Injury to the common peroneal nerve causes paralysis of the anterior group of muscles, the lateral group of muscles and the dorsalis pedis, in which the anterior group of muscles is paralyzed, the foot cannot be dorsiflexed, the toes are flexed and inversion is present; the long and short peroneal muscles are paralyzed, the external rotation force is sharply reduced, resulting in plantarflexion and inversion of the foot, which is called horseshoe clubfoot. The sensory impairment is manifested on the anterolateral side of the lower leg and the dorsum of the foot.