Deep Gluteal Layer (Short Rotator Group) Flashcards
Piriformis origin
Anterior sacrum (2nd to 4th segments), superior margin of greater sciatic notch
Piriformis insertion
Superior aspect of greater trochanter
Piriformis action
External rotation of extended thigh, abduction of flexed hip (joint stability)
Piriformis innervation
Anterior rami of S1*, S2 (nerve to piriformis) innervation occurs inside pelvic cavity
Obturator Internus origin
Pelvic surface of obturator foremen and membrane
Obturator Internus insertion
Trochanteric fossa
Obturator Internus action
External rotation of extended thigh, abduction of flexed hip (joint stability)
Obturator Internus innervation
Nerve to obturator internus L5, S1*
Obturator Externus origin
Margins of obturator foramen and membrane
Obturator Externus insertion
Trochanteric fossa
Obturator Externus action
External rotation of extended thigh
Obturator Externus innervation
Obturator nerve L3, L4*
Superior Gemellus origin
Ischial spine
Superior Gemellus insertion
Trochanteric fossa (blends with obturator internus)
Superior Gemellus action
External rotation of extended thigh, abduction of flexed hip (joint stability)
Superior Gemellus innervation
Nerve to obturator internus L5, S1*
Inferior Gemellus origin
Ischial tuberosity
Inferior Gemellus insertion
Trochanteric fossa (blends with obturator internus)
Inferior Gemellus action
External rotation of extended thigh, abduction of flexed hip (joint stability)
Inferior Gemellus innervation
Nerve to quadratus femoris L5, S1
Quadratus Femoris origin
Lateral border of ischial tuberosity
Quadratus Femoris insertion
Intertrochanteric crest (quadrate tubercle)
Quadratus Femoris action
External rotation of thigh, joint stability
Quadratus Femoris innervation
Nerve to quadratus femoris L5, S1
