1. The low back pain with sciatica is severe, radiating along the direction of sciatic nerve, which can radiate to the buttocks, the back of thighs, the outside of calves, even the outside of heels and the outside of dorsum of feet. It gets worse with coughing, sneezing, defecation or bending over, and gets better at rest. The whole onset process is obviously intermittent. 2. Local tenderness, with deep tenderness beside the lumbago 4.5 or lumbago 5 sacrum 1 spinous process or along the midline, often radiating along the sciatic nerve innervation area. 3. The waist is stiff, the physiological lordosis is straight, and scoliosis, sacrospinous muscle spasm and lumbar motion limitation may occur. 4. Straight leg elevation test and pressure test were positive. 5. The feeling, muscle strength and tendon reflex of lower limbs have changed, and muscle atrophy occurs in severe cases. It is suggested that piriformis syndrome is a common disease that causes acute and chronic sciatica. It is generally believed that the high branch of the common peroneal nerve passes through the piriformis muscle bundle.

Piriform muscle syndrome. Or the sciatic nerve passes through the piriformis muscle abdomen. When piriformis muscle is injured, congestion, edema, spasm, adhesion and contracture occur, the muscle space or the upper and lower holes of muscle become narrower, and the nerves and blood vessels passing through it are squeezed, resulting in a series of clinical and somatic symptoms, which is called piriformis muscle injury syndrome.