Weakness of the legs are considered to be caused by the following reasons: first, consider cervical spondylosis, especially spinal cord cervical spondylosis, when the cervical disc herniation compression of the spinal cord, it will cause both lower limbs power loss, weakness of the legs, walking unsteady, lower limb coordination loss, as walking on cotton in general. Secondly, lumbar spinal stenosis is considered. When the spinal stenosis compresses the nerve roots or lumbar spinal cord, there will be radiating pain and numbness in the lower limbs and loss of muscle strength in the lower limbs, which will also be manifested as weakness in the legs. Thirdly, water electrolyte disorders are considered, such as generalized weakness, especially weakness of the limbs, which may occur when there is low potassium, as well as walking weakness and unsteady walking.