The pelvic girdle is a bony structure in the human body that connects the lower limbs to the axial skeleton. It's also known as the os coxae, which is Latin for "bone of the hip."
Composition of the Pelvic Girdle
The pelvic girdle is composed of three fused bones:
- Ilium: The largest and uppermost bone of the pelvis. It forms the superior part of the acetabulum (the hip socket).
- Ischium: Forms the lower and back part of the hip bone. You sit on your ischial tuberosities.
- Pubis: Forms the anterior and inferior portion of the hip bone. The two pubic bones meet at the pubic symphysis.
| Bone | Description |
|---|---|
| Ilium | The largest, uppermost bone contributing significantly to the acetabulum. |
| Ischium | The lower, posterior bone featuring the ischial tuberosity (sitting bone). |
| Pubis | The anterior, inferior bone connected to its counterpart at the pubic symphysis. |
Function of the Pelvic Girdle
The primary functions of the pelvic girdle include:
- Weight Bearing: Transmits weight from the upper body to the lower limbs, especially during standing and locomotion.
- Protection: Protects the pelvic organs, including the bladder, rectum, and reproductive organs.
- Muscle Attachment: Provides attachment points for numerous muscles involved in movement and posture.
- Locomotion: Facilitates walking, running, and other forms of movement.
Pelvic Girdle vs. Pelvis
It's important to distinguish between the pelvic girdle and the pelvis. The pelvic girdle consists of the two hip bones (os coxae). The pelvis, on the other hand, is a broader term encompassing the two hip bones, the sacrum, and the coccyx. Therefore, the pelvic girdle is a component of the larger structure known as the pelvis.
In summary, the pelvic girdle is a crucial structure for weight-bearing, protection, muscle attachment, and locomotion, formed by the fusion of the ilium, ischium, and pubis.
