Origin
What is the origin of the Piriformis?
Anterior surface of sacrum between anterior sacral foramina
What is the insertion for the Piriformis?
Medial side of superior border of greater trochanter of femur
What is the function of the Piriformis?
Lateral rotation of the extended hip joint; abduction of flexed hip
What innervates the Piriformis?
Branches from S1 and S2
Which structures travel above the Piriformis?
Superior gluteal nerve/vessels
What is the origin of the Obturator Internus?
Anterolateral wall of true pelvis (deep surface of obturator membrane and surrounding bone)
What is the insertion of the Obturator Internus?
Medial surface of greater trochanter of femur
What is the action of the Obturator Internus?
Lateral rotation of the extended hip joint; abduction of flexed hip
What innervates the Obturator Internus?
Nerve to obturator internus
What structures travel through the Obturator canal?
Obturator nerve and vessels
What is the origin of the Gemellus Superior
External surface of ischial spine
What is the insertion of the Gemellus Superior
Along length of superior surface of the obturator interns tendon and into the medial side of greater trochanter of femur with obturator internus tendon
Laterally rotates the extended femur at hip joint; abducts flexed femur at hip joint
What innervates the Gemellus Superior
Nerve to obturator internus
The tendon of what muscle travels in the Lesser Sciatic Notch
Tendon of Obturator Internus
Upper aspect of ischial tuberosity
What is the insertion of the Gemellus Inferior
Along length of inferior surface of the tendon and obturator internus into the medial side of greater trochanter of femur with obturator internus tendon
What is the action of the Gemellus Inferior
Laterally rotates the extended femur at hip joint; abducts flexed femur at hip joint
What innervates the Gemellus Inferior?
Nerve to quadratus femoris
Name all the structures that travel below the Piriformis.
Sciatic nerve
Inferior gluteal nerve/vessels
Posterior femoral cutaneous nerve
Nerve to obturator internus and quadratus femoris nerves
Pudendal nerve/internal pudendal vessels
What is the origin of the Quadratus Femoris?
Lateral aspect of the ischium just anterior to the ischial tuberosity
What is the insertion of the Quadratus Femurs?
Quadrate tubercle on the intertrochanteric crest of the proximal femur
What is the action of the Quadratus Femoris?
Laterally rotates femur at hip joint
What innervates the Quadratus Femoris?
Nerve to quadratus femoris
Name the origin, insertion, action, and innervation of the Obturator Externus muscle.
Origin: external surface of obturator membrane and adjacent bone
Insertion: Trochanteric fossa
Action: Lateral hip rotation
Innervation: Obturator nerve (posterior division)