O and I Quiz #2 - Piriformis - quadratus femoris

Anterior surface of sacrum

Piriformis origin

Greater trochanter (through greater sciatic foramen)

Piriformis insertion

• Hip external rotation

• Hip abduction

• Hip internal rotation with hip flexed above 90°

Piriformis actions

Nerve to piriformis

Piriformis innervation

Ischial spine

Gemellus superior origin

Greater trochanter via tendon of obturator internus

Gemellus superior insertion

Hip external rotation

Gemellus superior actions

Nerve to obturator internus

Gemellus superior innervations

Internal surface of obturator foramen and membrane

Obturator internus origin

Greater trochanter

Obturator internus insertion

Hip external rotation

Obturator internus action

Nerve to obturator internus

Obturator internus innervation

• Origin: Ischial tuberosity

• Insertion: Greater trochanter via tendon of obturator internus

• Action: Hip external rotation

• Innervation: Nerve to quadratus femoris

Gemellus inferior

OIAI

• Origin:

  1. Pubis and ischium near obturator foramen

  2. External surface of obturator membrane

• Insertion: Trochanteric fossa

• Action: Hip external rotation

• Innervation: Obturator

Obturator externus OIAI

• Origin: Ischial tuberosity

• Insertion: Quadrate tubercle

• Action:

  1. Hip external rotation

  2. Hip adduction

• Innervation: Nerve to quadratus femoris

Quadratus femoris OIAI