The following causes should be considered: a. Foot deformity, clinically known as horseshoe foot, when the patient walks, the ankle joint is plantar flexed and the front half of the foot is on the ground, often caused by trauma, congenital deformity, neuropathy and other causes of Achilles tendon contracture and common peroneal nerve palsy. Second, the presence of brain lesions, such as cerebral palsy, cerebral hemorrhage, patients with sequelae of cerebral infarction, patients with cerebral hemangioma or brain tumor. Third, lumbar spine lesions, such as patients with lumbar spine trauma resulting in paraplegia. IV. Patients with post-polio sequelae.