(31) Pelvic girdle

Potomac Girdle

• The Potomac girdle connects the lower limbs to the body.

• Composed of the following bones:

  • Two ilia

  • Sacrum

• These bones together form the pelvic girdle.

Coxa Overview

• A coxa is composed of three separate bones that fuse together:

  • Ilium: The uppermost bone.

  • Ischium: The bone you sit on.

  • Pubis: Located in the anterior region, known as the pubic region.

• These bones fuse at a point called the acetabulum, which serves as a socket for the hip joint.

Bone Details

• Ilium:

  • Top ridge known as the iliac crest, important for muscle attachment (especially back muscles).

• Socket Formation:

  • The acetabulum is cup-shaped, where the head of the femur connects to form the hip joint (ball-and-socket joint).

• Greater Sciatic Notch:

  • A notch on the coxa that allows major nerves and blood vessels to pass to the lower limbs.

• Obturator Foramen:

  • A large hole in the coxal region, mostly covered by connective tissue.

  • Not primarily for blood vessels or nerves; its function is to reduce the weight of the trunk while maintaining strength.

Ischium Details

• Ischial Tuberosity:

  • The part of the ischium that is weight-bearing when seated.

  • Serves as a major muscle attachment site.

• Pubic Symphysis:

  • A cartilaginous joint connecting the two pubis bones.

  • Plays a critical role in weight distribution across the pelvis during walking.

  • Important for women during the birth process as it is the only point of flexibility during labor.

Potomac Girdle

The Potomac girdle is the part of your body that connects your legs to your body.

Bones in the Potomac Girdle

It is made up of three main bones:

• Two ilia: These are like the side parts of your hips.

• Sacrum: This is a bone in the middle of your lower back.Together, these bones are called the pelvic girdle.

What is a Coxa?

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A coxa is a special name for a part of your hip made from three smaller bones:

• Ilium: This is the top bone.

• Ischium: This is the bone that you sit on.

• Pubis: This is the front part of your hip.

How Coxa Works

These bones come together at a place called the acetabulum, which is like a cup where your leg bone (femur) sits, allowing you to move your legs in lots of ways!

More About the Ilium

• Iliac Crest: The top edge of the ilium is called the iliac crest. It’s important because many muscles attach to it, helping you move your back and legs.

• Acetabulum: This is the cup-shaped spot where your leg connects, letting you walk and run.

• Greater Sciatic Notch: A little space in the ilium that lets important nerves and blood vessels go down to your legs.

What About the Ischium?

• Ischial Tuberosity: This part is the one that supports you when you sit.

• Pubic Symphysis: This is a joint connecting the two pubic bones in the front. It helps with balance when you walk and is really important for women when they have babies because it can move a little!