Muscles Of The Gluteal Region Flashcards
The muscles of the gluteal region can be broadly divided into two groups:
- Superficial abductors and extenders
- Deep lateral rotators
Superficial abductors and extenders
Gluteus maximus, gluteus medius, gluteus minimus and tensor fascia lata.
Deep lateral rotators
Quadratus femoris, piriformis, gemellus superior, gemellus inferior and obturator internus.
Arterial supply to muscles of the gluteal region.
Mostly via the superior and inferior gluteal arteries - branches of the internal iliac artery.
Gluteus Maximus Attachments
Originates from the gluteal (posterior) surface of the ilium, sacrum and coccyx. It slopes across the buttock at a 45 degree angle, then inserts into the iliotibial tract and the gluteal tuberosity of the femur.
Gluteus Maximus Actions
It is the main extensor of the thigh, and assists with lateral rotation. However, it is only used when force is required, such as running or climbing.
Gluteus Maximus Innervation
Inferior gluteal nerve.
Gluteus Medius Attachments
Originates from the gluteal surface of the ilium and inserts into the lateral surface of the greater trochanter.
Gluteus Medius Actions
Abducts and medially rotates the lower limb. During locomotion, it secures the pelvis, preventing pelvic drop of the opposite limb.
Gluteus Medius Innervation
Superior gluteal nerve.
Gluteus Minimus Attachments
Originates from the ilium and converges to form a tendon, inserting to the anterior side of the greater trochanter.
Gluteus Minimus Actions
Abducts and medially rotates the lower limb. During locomotion, it secures the pelvis, preventing pelvic drop of the opposite limb.
Gluteus Minimus Innervation
Superior gluteal nerve.
Tensor Fascia Lata Attachments
Originates from the anterior iliac crest, attaching to the anterior superior iliac spine (ASIS). It inserts into the iliotibial tract, which itself attaches to the lateral condyle of the tibia.
Tensor Fascia Lata Actions
Assists the gluteus medius and minimus in abduction and medial rotation of the lower limb. It also plays a supportive role in the gait cycle.
Tensor Fascia Lata Innervation
Superior gluteal nerve.
Piriformis Attachments
Originates from the anterior surface of the sacrum. It then travels infero-laterally, through the greater sciatic foramen, to insert into the greater trochanter of the femur.
Piriformis Actions
Lateral rotation and abduction.
Piriformis Innervation
Nerve to piriformis.
What is the triceps coxae?
In some texts, the obturator internus and the gemelli muscles are considered as one muscle – the triceps coxae.
Obturator Internus Attachments
Originates from the pubis and ischium at the obturator foramen. It travels through the lesser sciatic foramen, and attaches to the greater trochanter of the femur.
Obturator Internus Actions
Lateral rotation and abduction.
Obturator Internus Innervation
Nerve to obturator internus.
The Gemelli – Superior and Inferior
The gemelli are two narrow and triangular muscles. They are separated by the obturator internus tendon.
The Gemelli Attachments
The superior gemellus muscle originates from the ischial spine, the inferior from the ischial tuberosity. They both attach to the greater trochanter of the femur.
The Gemelli Actions
Lateral rotation and abduction.
The Gemelli Innervation
The superior gemellus muscle is innervated by the nerve to obturator internus, the inferior gemellus is innervated by the nerve to quadratus femoris.
Quadratus Femoris Attachments
It originates from the lateral side of the ischial tuberosity, and attaches to the quadrate tuberosity on the intertrochanteric crest.
Quadratus Femoris Actions
Lateral rotation.
Quadratus Femoris Innervation
Nerve to quadratus femoris.
