Where is the pyriformis muscle in the human body? Pear-shaped muscle injury will have what performance?

There is a muscle called the pyriformis muscle on each side of the buttocks, which looks like a duck's pear. The pyriformis muscle is located on the deep side of the gluteus maximus muscle on the superficial surface of the buttocks, just above the back of the hip joint.

a

It starts at the center of the buttocks in front of the sacral vertebrae, the belly of the muscle diagonally across the pelvic floor, and ends at the top of the lateral bulge of the upper thigh at the top of the femur. Below the human waist there is a pelvis made of hard bone, which has two large sciatic foramina made of bone and ligaments side by side at its base. The foramen is closed up by a number of muscles and ligaments, the pyriformis being one of these muscles.

The sciatic foramen magnum is closed to leave blood vessels and nerves in the channel, the pear-shaped muscle on the lower part of their "traffic channel". The longest nerve in the human body - the sciatic nerve, that is, from the lower edge of the pear-shaped muscle through, through the back of the thigh, and then distributed to the calf and foot.

b

In addition to this, the upper and lower edges of the pyriformis muscle are passed by the superior gluteal neurovascular, posterior femoral cutaneous nerve, the inferior gluteal neurovascular bundle, and the pubic vascular nerve bundle. These structures in the channel are characterized by a high degree of variation in the morphology of the vessels, especially the veins, which are more variable and often overlap and intersect.

The clinical manifestation of pyriformis syndrome is sciatic nerve pain that radiates along the posterior aspect of one lower extremity, primarily in the calf and foot. Because the pain is more intense, the patient may develop a limp, and in severe cases, muscle atrophy of the calf may occur, and the skin sensation of the calf appears to be reduced. On clinical examination, the 4-word test (+). A striated or hard mass in the buttocks can be palpated. Sciatic nerve pull test (+), localized buttock tenderness (+), Tinel's sign (+). In those with a history of localized acetabular fracture, radiographs may show bone scab formation or displacement of the bone mass.

Most patients with pyriformis injury have excessive rotation, external rotation of the thigh, some have a history of cold at night, the pain occurs on one side of the buttocks, legs, cutting or burning pain, urination and defecation or loud coughing caused by increased intra-abdominal pressure can make the pain worse. Sometimes patients kneel down on both knees and can't sleep at night, which is very painful. Some patients also appear limp, the body in a semi-flexed position, the lumbar region is generally no pressure points.

c

The affected side of the gluteal muscle can have mild atrophy, the pear-shaped muscle area can be touched with a cord-like muscle bundles, local muscle tension when pressed deep pressure pain is obvious, and rebound pain, occasional perineal discomfort, numbness of the outside of the calf, the lower limbs to the inward rotation, the pain is aggravated by the internal contraction.