15 Structural Difference Between Male And Female Pelvis

In Human anatomy, the pelvis, also referred to as bony pelvis is a basin-shaped complex of bones. The pelvis has several important functions. Its primary role is to support the weight of the upper body when sitting and to transfer this weight to the lower limbs when standing. It serves as an attachment point for trunk and lower limb muscles, and also protects the internal pelvic organs.

The pelvis is usually divided into two separate anatomic regions: the pelvic girdle and the pelvic spine. The pelvic girdle, also referred to as the hip bone, is composed of three fused bones: the ilium, ischium and the pubic bone.

The pelvic spine is the posterior portion of the pelvis below the lumbar spine, and comprises of the Sacrum and coccyx. The two pelvic bones are connected anteriorly by the pubic symphysis while posteriorly they articulate with the pelvic spine to form the sacroiliac joints.

Male Vs Female Pelvis

The differences between the adult female and male pelvis relate to function and body size. In general, the bones of the male pelvis are thicker and heavier, adapted for support of the male’s heavier physical build and stronger muscles.

The greater sciatic notch of the male hip bone is narrower and deeper than the broader notch of females. Because the female pelvis is adapted for childbirth, it is wider than the male pelvis, as evidenced by the distance between the anterior superior iliac spines.

The ischial tuberosities of females are also farther apart, which increases the size of the pelvic outlet. Because of this increased pelvic width, the subpubic angle is larger in females (greater than 70 degrees) than it is in males (less than 70 degrees).

The female sacrum is wider, shorter, and less curved, and the sacral promontory projects less into the pelvic cavity, thus giving the female pelvic inlet (pelvic brim) a more rounded or oval shape compared to males.

The lesser pelvic cavity of females is also wider and more shallow than the narrower, deeper, and tapering lesser pelvis of males. Because of the obvious differences between female and male hip bones, this is the one bone of the body that allows for the most accurate sex determination.

Structural Characteristic of Male Pelvis

• Generally, the male pelvis is larger and heavier than the female pelvis, reflecting the overall larger body size of males.
• The pelvic inlet (the upper opening of the pelvis) is narrower in males, which may result in a more funnel-shaped pelvic cavity.
• The male pelvic cavity is heart-shaped, with a narrower anterior (pubic) segment and a broader posterior (sacral) segment.
• The sacrum, the fused triangular bone at the base of the spine, tends to be more massive and vertically oriented in males.
• The sciatic notch, the space on each side of the sacrum that forms the greater sciatic foramen, is narrower in males compared to females.
• The iliac wings, the broad, curved portions of the ilium bone, have less lateral flare in males.
• The angle formed by the two pubic bones at the symphysis pubis (the front joint of the pelvic girdle) is less than 90 degrees in males, resulting in an acute subpubic angle.
• The pelvic outlet (the lower opening of the pelvis) is generally smaller in males.
• The coccyx (tailbone) may be more prominent in males.
• The joint between the sacrum and the ilium bone (sacroiliac joint) is longer and narrower in males.
• The pubic symphysis, the joint that connects the two pubic bones at the front of the pelvis, tends to be more vertical and robust in males.
• The obturator foramen, the hole formed by the ischium and pubis bones, is generally larger in males.
• The angle formed by the pubic rami bones, known as the pelvic arch angle, is smaller in males.
• The bones of the male pelvis are thicker and more robust to withstand the increased stresses associated with physical activities and bearing weight.

Structural Characteristic of Male Pelvis

• The pelvic inlet (the upper opening of the pelvis) is wider in females compared to males. The pelvic outlet (the lower opening of the pelvis) is also larger in females to facilitate childbirth.
• The female pelvic cavity is shallower than the male pelvis.
• The shape of the female pelvic cavity is more rounded and spacious, allowing for the passage of the baby during childbirth.
• The bones of the female pelvis are usually less robust and lighter compared to the male pelvis.
• The acetabulum, the socket that articulates with the head of the femur, may be smaller in females compared to males.
• The angle formed by the two pubic bones at the symphysis pubis (the front joint of the pelvic girdle) is wider than 90 degrees in females, resulting in a larger subpubic angle.
• The superior aperture of the lesser pelvis (pelvic inlet) is larger, more nearly circular and has greater obliquity.
• The sciatic notch, the space on each side of the sacrum that forms the greater sciatic foramen, is wider in females compared to males.
• The anterior iliac spines are more widely separated- thus the greater prominence of the hips laterally.
• The inferior aperture of the lesser pelvis (pelvic outlet) is larger and the coccyx is more moveable. The coccyx (tailbone) may be smaller and less prominent.
• The joint between the sacrum and the ilium bone (sacroiliac joint) is shorter and wider in females.
• The angle formed by the pubic rami bones, known as the pubic arch, is usually broader and more horizontally oriented in females.
• The ischial spines, bony protrusions on the ischium bone, may be more prominent in females.
• The boundary between the pelvic inlet and the pelvic cavity, known as the pelvic brim, is usually smoother and more rounded in females.
• The greater sciatic notch, a space below the posterior iliac spine, is generally wider in females.

Male vs Female Pelvis In Tabular Form