Piriformis muscle
The piriformis muscle has its origin upon the front surface of the sacrum, and inserts onto the greater trochanter of the femur.[1] The piriformis muscle originates from the anterior (front) surface of the sacrum[2][3] by three fleshy digitations attached to the second, third, and fourth sacral vertebra.[1] It also arises from the superior margin of the greater sciatic notch,[4] the gluteal surface of the ilium (near the posterior inferior iliac spine), the sacroiliac joint capsule, and (sometimes) the sacrotuberous ligament (more specifically, the superior part of the pelvic surface of this ligament).[2] Abduction of the flexed thigh is important in the action of walking because it shifts the body weight to the opposite side of the foot being lifted, which prevents falling.Findings suggest the possibility that Botulinum toxin type B may be of potential benefit in the treatment of pain attributed to piriformis syndrome.[10] The piriformis muscle was first named by Adriaan van den Spiegel, a professor from the University of Padua in the 16th century.
lateral rotator groupSacrumGreater trochanterArteryInferior gluteallateral sacralsuperior gluteal arteryNerve to the piriformisActionsExternal rotatorAnatomical terms of musclepear-shapedmusclegluteallower limbspiriformis nerveanterior (front) surfacesecond, third, and fourth sacral vertebragreater sciatic notchposterior inferior iliac spinesacroiliac jointsacrotuberous ligamenttendonsuperior gemellusinferior gemellusobturator internusinnervatedrectumsacral plexusgluteus mediuspelviship jointgreater sciatic foramensciatic nervegluteus minimuslateral rotators of the hipquadratus femorisgemellus inferiorgemellus superiorobturator externusPiriformis syndromesciaticaBotulinum toxinAdriaan van den SpiegelUniversity of PaduaDeep gluteal syndromepublic domainGray's AnatomyUniversity of WashingtonMuscles of the hiphuman legIliac regionIliopsoasPsoas majorPsoas minorIliacusButtocksGluteal musclesMaximusMediusMinimusTensor fasciae lataeInternal obturatorExternal obturatorcompartmentsAnteriorSartoriusQuadricepsRectus femorisVastus lateralisVastus intermediusVastus medialisArticularis genusPosteriorHamstringBiceps femorisSemitendinosusSemimembranosusMedialPectineusGracilisAdductorLongusBrevisMagnusFasciaFemoral sheathFemoral canalFemoral ringAdductor canalAdductor hiatusMuscular lacunaFascia lataIliotibial tractLateral intermuscular septum of thighMedial intermuscular septum of thighCribriform fasciaTibialis anteriorExtensor hallucis longusExtensor digitorum longusFibularis (peroneus) tertiusTriceps suraeGastrocnemiusSoleusAccessory soleusAchilles tendonPlantaristarsal tunnelFlexor hallucis longusFlexor digitorum longusTibialis posteriorPopliteusLateralFibularis (peroneus) musclesPes anserinusIntermuscular septaTransverseExtensor hallucis brevisExtensor digitorum brevisAbductor hallucisFlexor digitorum brevisAbductor digiti minimiQuadratus plantaeLumbrical muscleFlexor hallucis brevisAdductor hallucis