piriformis muscle


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to piriformis muscle: Piriformis syndrome, Psoas muscle

pi·ri·for·mis mus·cle

(pir'i-fōrm'is mŭs'ĕl)
Origin, margins of pelvic sacral foramina and greater sciatic notch of ilium; insertion, upper border of greater trochanter; action, rotates thigh laterally; nerve supply, nerve to piriformis (sciatic plexus).
Synonym(s): musculus piriformis [TA] , piriform muscle.

piriformis muscle

Thigh muscle. Origin: anterior surface of sacrum. Insertion: upper part of greater trochanter of femur. Nerve: spinal L5-S2. Action: laterally rotates thigh.
See also: muscle
References in periodicals archive ?
1: piriformis muscle; 2: gluteus medius muscle; 3: inferior gluteal nerve; 4: sciatic nerve; 5: posterior femoral cutaneous nerve.
Keywords: Piriformis muscle syndrome Sciatic nerve MRI.
The patient had a piriformis muscle injection under ultrasound guidance where 5 cc of 1% lidocaine solution was injected in the targeted muscle.
In the sacral plexus, entrapment of the sciatic nerve at the greater sciatic foramen (piriformis syndrome) may be secondary to asymmetry of the piriformis muscle size or anatomic variations in the course of the sciatic nerve relative to the piriformis muscle (Figure Obtaining a sequence perpendicular to the piriformis muscle is crucial in identification of these anatomic variants.
Symptoms also may result from "pseudosciatica," or non-spinal causes, such as piriformis syndrome (a tightening of the piriformis muscle in the buttocks), or be mistaken for hip arthritis or trochanteric bursitis, an inflammation of a bursa sac in the hip.
Some of them, such as spondylolysis and piriformis syndrome (a condition in which the piriformis muscle irritates the sciatic nerve, causing pain ha the buttocks and referring pain along the course of the sciatic nerve), of ten are seen ha different sports or circumstances as well.
The onset is gradual, caused not only by wallets, but by any object (like carrying golf balls around) that presses on the piriformis muscle in the buttocks.
Special imaging for nerves with magnetic resonance neurography can detect piriformis muscle syndrome--a condition in which the narrow piriformis muscle irritates or pinches the sciatic nerve.
A rare cause is entrapment syndrome of the SGN as a result of compression by tendinous fibers of the piriformis muscle (Kountouris & Okur, 1982; Plihal, Saudan, Vischer, & Roth, 1989; Rask, 1980).
Sciatic pain due to nerve pressure has three possible sources: bony spurs on the surface of the vertebrae pressing on the nerve, pressure from a damaged spinal disk, and muscle spasms--particularly in the piriformis muscle, which may tighten enough to press on the nerves and cause pain.
Sciatic pain due to nerve pressure has three possible sources: bony spurs on the vertebrae pressing on the nerve, pressure from a damaged spinal disk, and muscle spasms--particularly in the piriformis muscle, which may tighten enough to press on the nerves and cause pain.
Sciatic pain ( occasionally the sciatic nerve runs through the piriformis muscle in the buttock.