The bony component of the gluteal (buttocks) region consists of two pelvic bones (os coxae) joined anteriorly by the symphysis pubis and posteriorly by the sacrum. Each os coxa is composed of three fused bones: ilium, ischium, and pubis. The bones of the gluteal region contain foramina (notches), which serve as conduits for nerves and blood vessels that travel between the pelvis, gluteal region, perineum, and lower limb. Muscles of the gluteal region primarily act on the hip joint.
The hip joint is a synovial, ball-and-socket joint. The “ball” is the head of the femur, and the “socket” is the acetabulum of the pelvic bone. The motions of the hip joint are as follows (Figure 35-1A):
Flexion. Movement anterior in the sagittal plane.
Extension. Movement posterior in the sagittal plane.
Abduction. Movement away from the midline in the frontal plane.
Adduction. Movement toward the midline in the frontal plane.
Internal (medial) rotation. Movement toward the midline in the transverse or axial plane.
External (lateral) rotation. Movement away from the midline in the transverse or axial plane.
Circumduction. A combination of hip joint motions that produces a circular motion.
A. Actions of the hip joint. The right gluteal region illustrating the posterior view of the superficial gluteal muscles (B) and the deep gluteal muscles (C).
MUSCLES OF THE GLUTEAL REGION
The muscles of the gluteal region primarily act on the hip joint, producing extension, medial rotation, lateral rotation, and abduction (Table 35-1). In addition to producing motion, the muscles of the gluteal region are important for stability of the hip joint as well as for locomotion.
TABLE 35-1.Muscles of the Gluteal Region ||Download (.pdf) TABLE 35-1. Muscles of the Gluteal Region
|Muscle ||Proximal Attachment ||Distal Attachment ||Action ||Innervation |
|Gluteal region |
|Tensor fascia lata ||Lateral aspect of crest of ilium between anterior superior iliac spine and tubercle of crest ||Iliotibial tract of fascia lata ||Stabilizes knee in extension ||Superior gluteal n. (L4–S1) |
|Gluteus maximus ||Ilium behind posterior gluteal line, sacrum, coccyx, and sacrotuberous ligament ||Iliotibial tract and gluteal tuberosity of femur ||Powerful extensor of flexed femur at hip joint; lateral stabilizer of hip and knee joints ||Inferior gluteal n. (L5–S2) |
|Gluteus medius ||Ilium between anterior and posterior gluteal lines ||Greater trochanter ||Abducts femur at hip joint; holds pelvis secure over stance leg and prevents pelvic drop on opposite swing side during walking; hip internal rotation ||Superior gluteal n. (L4–S1) |
|Gluteus minimus ||Ilium between anterior and inferior gluteal lines |
|Piriformis ||Anterior surface of sacrum ||Greater trochanter ||Laterally rotates the hip joint ||Nerve to ...|