Muscles of hip region (part 1)

Muscles of the hip region are divided in two groups comprised of the following muscles:

NOTE: tensor fasciae latae, piriformis, obturator muscle, gemellus muscles and quadratus femoris are shown in the next slides.

 

Iliopsoas

The iliopsoas muscle consists of two muscles, the iliacus and psoas major, which have different areas of origin but common insertion. The iliacus is a flat skeletal muscle of the pelvis, filling the iliac fossa. The psoas major is a long muscle of the pelvis that joins with the iliacus to form the iliopsoas. It has a superficial and a deep part.

 

Origin: the iliacus originates from the iliac fossa, internal lip of the iliac crest, lateral aspect of the sacrum, anterior sacroiliac ligament, iliolumbar ligament; the superficial part of the psoas major - from the lateral aspects of the vertebral bodies of the twelfth thoracic and first four lumbar vertebrae (T12 - L4) and lateral sides of the intervertebral discs between them, deep part - from the transverse processes of all lumbar vertebrae (L1 - L5).

Insertion: both muscles insert on the lesser trochanter of the femur. 

Action: the main actions of the iliopsoas include flexion and external rotation of the thigh at the hip joint, as well as flexion of the trunk, if the leg is fixed. 

Innervation: iliacus - femoral nerve (L2, L3), psoas major - anterior rami of lumbar spinal nerves (L1 - L3).

Blood supply: iliacus - iliolumbar artery, branches of femoral, obturator and deep circumflex femoral arteries; psoas major - iliolumbar artery, lumbar arteries, deep circumflex femoral artery.

 

Psoas minor

The psoas minor is a long, slim skeletal muscle lying anterior to the psoas major muscle.

 

Origin: lateral surfaces of the bodies of the twelfth thoracic (T12) and first lumbar (L1) vertebrae. 

Insertion: iliopubic eminence, pectineal line.

Action: stabilizing of the pelvis and the hip joint, flexion of the trunk.

Innervation: anterior ramus of the first lumbar spinal nerve (L1).

Blood supply: lumbar arteries, lumbar branch of iliolumbar artery.

 

Gluteus maximus

The gluteus maximus is the largest and most superficial of the three gluteal muscles and forms the surface anatomy of the gluteal region or buttocks. 

 

Origin: outer (gluteal) surface of the ilium behind the posterior gluteal line, posterior surfaces of the sacrum and coccyx, sacrotuberous ligament, and thoracolumbar fascia.

Insertion: iliotibial tract of the fascia lata and gluteal tuberosity (on the diaphysis of the femur) between the adductor magnus and vastus lateralis muscles.

Action: extension and external rotation of the thigh, abduction of the thigh (with superior fibers), and also support for the hip joint.

Innervation: inferior gluteal nerve (L5 - S2).

Blood supply: inferior and superior gluteal arteries.

 

Gluteus medius

The gluteus medius is one of the three paired gluteal muscles and it is situated beneath the gluteus maximus.

 

Origin: gluteal surface of the ilium between the anterior and posterior gluteal lines.

Insertion: along with the gluteus minimus, this muscle inserts at the greater trochanter of the femur. 

Action: abduction of the thigh; anterior fibers provide internal rotation of the thigh; posterior fibers are responsible for external rotation of the thigh. Also, it stabilizes the pelvis. 

Innervation: superior gluteal nerve (L4 - S1).

Blood supply: superior gluteal artery.

 

Gluteus minimus

The gluteus minimus is the smallest of the three gluteal muscles and it is situated below the gluteus medius. 

 

Origin: gluteal surface of the ilium between the anterior and inferior gluteal lines.

Insertion: along with the gluteus medius, it inserts at the greater trochanter of the femur. 

Action: abduction of the thigh, anterior fibers of the muscle also provides internal rotation of the thigh, stabilization of the pelvis. 

Innervation: superior gluteal nerve (L4 - S1).

Blood supply: superior gluteal artery.