Sciatica is a common symptom in orthopedic clinics, and most of the diseases that cause sciatica are lumbar spine diseases, such as lumbar disc herniation and lumbar spine slippage, etc. A small number of them can also be caused by pyriform muscle syndrome. The main method to check sciatica is through the straight leg elevation test. The specific operation is to put the patient in a supine position, the examiner holds the patient’s knee with one hand and the patient’s heel with the other hand, and slowly elevate the lower limb, checking the healthy side first and recording the maximum angle of elevation. The angle between the lower limb and the bed surface at the time of radiating pain is recorded. Patients with sciatica will have radiating pain induced in the posterior thigh in the range of 30-60 degrees. The straight leg raise test is recommended to be performed by a specialist to avoid false positives or false negatives. The sciatic nerve is the thickest peripheral nerve in the human body, and is formed by the convergence of the lumbar 4-5 nerve roots and the anterior branch of the spinal nerve in the sacral 1-3 segments, which crosses the pear-shaped muscle in the buttock to the posterior thigh, and can be divided into two branches of the tibial and common peroneal nerves at the popliteal fossa, mainly innervating the sensation and movement of the lower limbs.