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.
Distinct Features Of The Male Pelvis
- Male pelvis is smaller and narrower with heavier and thicker bones.
- It has a longer and narrower sacrum.
- The pelvis has a heart-shaped pelvic inlet.
- It consist of an acetabulum that is larger
- Ilium of male pelvis is more vertical with more curved iliac crest
- In Male pelvis, ischial tuberosity is longer, close together and more laterally projecting.
- The pelvis has a v-shaped pubic arch.
- It pelvis has a narrower sciatic notch.
- The coccyx of a male pelvis is projected inwards (less curved anteriorly) and immovable.
- Male pelvis is designed to support a heavy body with a stronger muscle structure.
- In male pelvis, the obturator foramen is round.
- A male pelvic bone is heavier, taller and much thicker
- The pelvic outlet in male pelvis is narrower.
Distinct Features Of The Female Pelvis
- The bones are more delicate-thin and light
- The pelvis is less massive and more shallow
- The ilia are less sloped
- The superior aperture of the lesser pelvis (pelvic inlet) is larger, more nearly circular and has greater obliquity.
- The anterior iliac spines are more widely separated- thus the greater prominence of the hips laterally.
- The cavity of the pelvis is shallow and wider.
- The obturator foramina are triangular – oval in shape and smaller in size than the male circular foramina.
- The acetabula are smaller and look more distinctly foward.
- The sciatic notches are wider and shallower.
- The pubic symphysis is less deep.
- The superior pubic ramus is longer than the width of the acetabulum.
- Sacrum is shorter, wider and the upper part is less curved, so the sacral promontory is less imposing into the pelvic cavity.
- The inferior aperture of the lesser pelvis (pelvic outlet) is larger and the coccyx is more moveable.
- The pubic arch is wider and more rounded than in male where it is an angle rather than an arch.
- The muscle attachments are more poorly marked.
- The spines of the ischia project less inward hence not protruding as much into the pelvic cavity.
- The Ischia tuberosities and the acetabula are more wider apart.
Difference Male And Female Pelvis In Tabular Form
|Elements of Comparison||Male Pelvis||Female Pelvis|
|Size||Male pelvis is smaller and narrower with heavier and thicker bones.||Female pelvis is bigger and wide with lighter and denser bones.|
|Sacrum||Has a longer and narrower sacrum.||Has a sacrum that is wider, shorter and less curved.|
|Pelvic Inlet/Brim||Has a heart-shaped pelvic inlet||Has pelvic inlet that is slightly oval in shape.|
|Acetabulum||The acetabulum is larger||The acetabulum is smaller|
|Ilium||Ilium of male pelvis is more vertical with more curved iliac crest.||The Ilium of female pelvis is less vertical with less curved iliac crest.|
|Ischial tuberosity||The ischial tuberosity is longer, close together and more laterally projecting.||The ischial tuberosity is shorter, farther apart and more medially projecting.|
|Pubic Arch||Has a v-shaped pubic arch||Has a pubic arch that is wider.|
|Sciatic Notch||Sciatic notch is narrower||Sciatic notch is wider|
|Coccyx||Coccyx of a male pelvis is projected inwards (less curved anteriorly) and immovable.||Female pelvis has a flexible and straighter coccyx.|
|Purpose of Design||Male pelvis is designed to support a heavy body with a stronger muscle structure.||The female pelvis has been designed for purposes of childbearing and easier delivery.|
|Obturator foramen||The obturator foramen is round||The obturator foramen is oval.|
|Pelvic Bone||Male pelvic bone is heavier, taller and much thicker||Female pelvic bone is thinner and denser.|
|Pelvic outlet||Pelvic outlet in male pelvis is narrower.||Pelvis outlet in female pelvis is wider.|
What is the main difference between Male and Female Pelvis?
The pelvis forms the base of the spine as well as the socket of the hip joint. The pelvis bones include the hip bones, sacrum and coccyx. The anatomy of the pelvis varies depending on whether you are male or female. In males, the pelvis is narrower, higher and more compact than that of their female counterpart. It is designed for bipedal movement rather than pregnancy and childbirth. On the other hand, female pelvis is wider and lower, making it more suitable for pregnancy and childbirth.