Posterior thigh pain may be caused by excessive internal or external rotation or abduction of the hip joint, which strains the pear-shaped muscle, and the spastic pear-shaped muscle compresses the sciatic nerve, which may produce pain in the posterior hip and posterior thigh. The pear-shaped muscle is a small muscle in the deep layer of the hip, starting from the lateral edge of the sacral foramen in front of the 2nd to 4th sacral vertebrae and ending at the greater trochanter of the femur, mainly cooperating with the internal and external muscles of the hip and other muscles to make the thigh abduct and externally rotate, and is innervated by the sacral plexus nerve. The foramen is divided into the superior foramen and the inferior foramen of the sciatic muscle. The sciatic nerve mostly passes out of the pelvis to the buttocks through the inferior foramen of the pear muscle, while some with anatomical variations pass through the superior foramen of the pear muscle. Most patients have a history of trauma, such as flashing, twisting, crossing, standing, squatting with heavy objects on the shoulder, walking with weight and getting cold. Certain actions such as lower limb abduction, external rotation or squatting into a straight position when the pear-shaped muscle elongation, stretching and injury to the pear-shaped muscle. After the injury of the pear-shaped muscle, local congestion and edema or spasm, repeated injury leads to hypertrophy of the pear-shaped muscle, resulting in narrowing of the pear-shaped hole, which can directly compress the sciatic nerve and appear pear-shaped muscle syndrome.