Sensory, muscular, and neurological abnormalities of the lower extremities often occur in thoracic spinal stenosis, and the clinical manifestations of the disease are mainly a series of syndromes of blood supply circulation to the thoracic spinal cord, sensory, muscular, and neurological abnormalities of the lower extremities caused by incomplete compression of the thoracic medulla. Thoracic spinal stenosis is a disease in which the thoracic spinal cord and nerve roots are compressed due to congenital or acquired degenerative factors, resulting in corresponding clinical symptoms and signs. The thoracic segment of the spinal cord has impaired blood supply and circulation, sensory and motor conduction caused by the compressor. There are many mechanisms that cause thoracic spinal stenosis, including congenital: spinal canal hypoplasia and shortened pedicles; hereditary abnormalities of bone metabolism such as Paget’s disease; and Vit-D resistant bone disease. There are also acquired ones: nephrotic abnormalities of bone metabolism, fluorosis. The most common clinical condition is due to strain factors. The correct diagnosis relies first on a detailed history and a thorough neurological examination. The disease should be highly suspected if the following conditions are present: 1. persistent or progressively increasing back pain and radiating pain, the latter radiating only in the direction of the intercostal nerve course and not to the lower extremities as in sciatica; 2. progressively increasing weakness of the lower extremities; 3. clumsy gait and limp; 4. unexplained numbness and muscle spasms (convulsions) of the lower extremities; 5. fasciculation of the trunk or lower extremities; with 2 to 3 of the above For those with 2 to 3 of the above, further imaging and electrophysiological examinations are required to clarify the diagnosis.