Leg weakness is more common in the elderly, the causes of which are mainly the following: 1, the sudden appearance of leg weakness on one side, need to consider stroke, cerebral infarction or cerebral hemorrhage caused. Lumbar disc herniation can also compress the nerves causing weakness or even numbness on one side of the limb, accompanied by discomfort, this side of the limb weakness, numbness often has a gradual, recurring characteristics, the course of the disease is long, do lumbar spine CT or MRI to help identify; 2, bilateral lower limb weakness, to consider spinal cord lesions, such as spinal cord occupational lesions can compress the spinal cord, causing bilateral leg weakness, is also a slowly progressive disease The lumbar spine can be identified by CT, MRI, and neurophysiological testing. The common cause of lower extremity weakness in the elderly is senile osteoporosis; a small percentage of bilateral lower extremity arterial occlusions, which cause lower extremity arterial ischemia, can lead to lower extremity leg weakness. In addition to the symptoms of weakness of the legs, the disease is also characterized by thinning of the skin, thinning of the hair, and weakening of the bilateral dorsalis pedis artery pulsations on physical examination.