Piriformis muscle

The piriformis muscle is (Latin for " pear-shaped muscle " ), a flat, pyramidal shaped to pear-shaped skeletal muscle of the lower extremity, specifically the deep layer of the hip muscles. It extends on the inside of the basin ( pelvis ) to the thigh bone (femur).

Ungulates in the muscle is not trained.

Course

Source surface of the pear-shaped muscle is the lateral (lateral ) inner surface (facies pelvina ) of the sacrum ( os sacrum ), where he ( anterior sacral foramina I-IV ) arises with several prongs fleshy from the bone between the four anterior sacral holes. More fibrous bands originate from the upper ( superior ) edge of the large collection of the pelvic line ( greater sciatic notch ) on the ischium ( ischium ).

From there it passes through the large ischial hole ( greater sciatic foramen ), which he divided and continues to the inside of the tip (apex ) of the greater trochanter ( great trochanter ) of the femur (femur ) to. His tendon joins before their approach in the bone often with the tendons of the upper and lower twin muscle (musculus musculus gemellus superior and inferior gemellus ) and the obturator internus muscle.

Function

The pear-shaped muscle rotates the thigh outward state, straddling him off to the side (abduction ) and stretches it (extension ) and takes him to the back ( retroversion ).

When the predators his tendon combined with the gluteus medius, whereby the two muscles are common to a pure hip extensors.