Gluteal Region and Posterior Thigh Flashcards
What are the 9 muscles of the gluteal region?
Gluteus maximus Gluteus medius Gluteus minimus Tensor fasciae latae Piriformis Obturator internus superior gemellus inferior gemellus quadratus femoris
What is the nerve supply and action of the gluteus maximus?**
Supplied by the inferior gluteal nerve
-extends and laterally rotates the femur at the hip joint
-helps maintain kneejoint in extension
=note only called into action during rapid and powerful extension, not during normal gait. used going upstairs, climbing etc
What is the nerve supply of the gluteus medius nerve, and what is its function?
Supplied by the superior gluteal nerve
-abducts and medially rotates the femur at the hip joint
What is the nerve supply of the gluteus minimus, and what is its action?
Is supplied by the superior gluteal nerve
-abducts and medially rotates femur at hip joint
What are the 2 chief abducts of the thigh?**
gluteus medius and gluteus minimus
-note that they also steady the pelvis while walking
What occurs if the gluteus medius and minimus are paralyzed unilaterally?
results in Trendelenburg gait
Pelvis is dropped on the unaffected side and there is lateral flexion of the trunk towards the paralyzed side in order to compensate for the shift in center of gravity
What is the nerve supply of the tensor fasciae latae, and what is its action?
supplied by the superior gluteal nerve
flexes and abducts the femur at the hip joint
-The tensor fasciae latae (along with the gluteus maximus) insert in the iliotibial tract, and assist in stabilizing the knee in extension; also help stabilize hip joint
What is the nerve supply of the piriformis, and what is its action?
supplied by the nerve to the piriformis
Laterally rotates the femur at the hip joint
What are the 4 muscles below the piriformis?
Obturator internus superior gemellus inferior gemellus quadratus femoris =they are all pure lateral rotators
What is the nerve supply and action of the obturator internus?
Supplied by the nerve to obturator internus
laterally rotates the femur at the hip joint
What is the nerve supply and action of the superior gemellus?
nerve to obturator internus
laterally rotates the femur at the hip joint
What is the nerve supply and action of the inferior gemellus?
supplied by the nerve to the quadratus femoris
laterally rotates the femur at the hip joint
What is the nerve supply and action of the quadratus femoris?
supplied by the nerve to the quadratus femoris
laterally rotates the femur at the hip joint
On the anterior surface of what muscle does the sacral plexus lie?
On the anterior surface of the piriformis muscle
What are the 7 major branches of the sacral plexus? Through which foramen do they all leave the pelvis?
Sciatic nerve (L4 - S3) Posterior cutaneous nerve of the thigh Superior gluteal nerve Inferior gluteal nerve Nerve to the quadratus femoris Pudendal nerve Nerve to obturator internus
All leave the pelvis through the greater sciatic foramen
How does the sciatic nerve emerge from the pelvis? What muscle does it reach?
Through greater sciatic foramen below the piriformis muscle
Passes posterior surface of superior gemellus, obturator internus, inferior gemellus, and quadratus femoris to reach back of adductor magnus