Muscles of the Gluteal Region: Anatomy, Attachments, Actions, and Innervation

Comprehensive practice flashcards reviewing the anatomical origins, insertions, actions, and innervations of the gluteus maximus, gluteus medius, gluteus minimus, and piriformis muscles.

Which gluteal muscle is illustrated in diagram A?

Gluteus maximus

What is the origin (O) of the gluteus maximus?

Posterior iliac crest, sacrum + coccyx, and sacrotuberous + sacroiliac ligaments.

What is the insertion (I) of the gluteus maximus?

Gluteal tuberosity + iliotibial band.

What are the actions (A) of the gluteus maximus?

Hip extension, external rotation, abduction, and posterior pelvic tilt.

What is the innervation (N) of the gluteus maximus?

Interior gluteal herve (inferior gluteal nerve).

Which muscle of the gluteal region is highlighted in diagram B?

Gluteus medius

What is the origin (O) of the gluteus medius?

Gluteal surface of ilium.

What is the insertion (I) of the gluteus medius?

Greater trochanter of femur.

What is the primary action (A) of the gluteus medius on the hip?

Hip abduction.

How do the actions of the anterior (A) and posterior (P) fibers of the gluteus medius differ?

A fibers perform internal rotation + flexion, whereas P fibers perform external rotation + extension (ext.).

What nerve (N) provides innervation to the gluteus medius?

Superior gluteal nerve.

Which deep gluteal muscle is depicted in diagram C?

Gluteus minimus

What is the origin (O) of the gluteus minimus?

Gluteal surface of ilium.

What is the insertion (I) of the gluteus minimus?

Anterior aspect of greater trochanter of the femur.

What are the actions (A) of the gluteus minimus?

Hip abduction, internal rotation + flexion.

What nerve (N) innervates the gluteus minimus?

Superior gluteal nerve.

Which muscle traversing between the sacrum and the femur is displayed in the diagram?

Piriformis

What is the origin (O) of the piriformis?

Anterior surface of the sacrum.

What is the insertion (I) of the piriformis?

Greater trochanter.

What is the action (A) of the piriformis, and how does it change with hip flexion?

Hip external rotation; when hip flexed $> 90^{\circ}$, it becomes internal rotation.

What is the innervation (N) of the piriformis?

Sacral plexus.