In this anatomy lesson, I’m going to highlight the major differences between the male pelvis and the female pelvis. If you were to walk into a crime scene containing skeletal remains, one of the quickest ways to determine the sex of the body would be to examine the pelvis.
Male vs Female Pelvis
Let’s take a look at an illustration of a male pelvis (left) and female pelvis (right) to understand some of these key differences.
The Female Pelvis is Shorter and Wider than the Male Pelvis
The iliac crest of the male pelvis rises higher than the iliac crest of the female pelvis, and there is a greater distance between the anterior superior iliac spines of the female pelvis when compared to the male pelvis. This usually gives women a curvier appearance in the hip region, as compared to the average male. The female pelvic cavity is also going to be shallower, whereas the male pelvic cavity is deeper.
The Female Pelvis is Lighter
Although the female pelvis is wider than the typical male pelvis, these bones are thinner and lighter than the denser, rougher bones of the male pelvis.
Pubic Arch Differences in Subpubic Angle
Next, notice the notched area under the pubic symphysis, which is called the pubic arch. This arch is typically going to be much wider in women than in men. You can remember this by thinking that when a woman gives birth to a child, she’ll have to spread her legs wide to do so.
The subpubic angle is the angle produced by the inferior rami of the pubis, which creates the pubic arch. In women, the subpubic angle will generally be equal to or greater than 80 degrees (obtuse), which is similar to the shape of the letter “L”. In men, the pubic arch is narrower, creating a subpubic angle that is usually less than or equal to 70 degrees (acute), making it a similar angle to an upside down “V.” These figures are not exact and can vary, depending on the source you read. For example, researchers in one study measured the subpubic angle on 109 pelves, and they found that women had a possible subpubic angle range of 64-100 degrees, whereas men had a possible range of 48-81 degrees.
The Female Pelvic Brim is Oval-Shaped; The Male Pelvis is Heart-Shaped
The pelvic brim of the female is generally larger than the male’s inlet, which facilitates childbirth. The male inlet is smaller and heart-shaped, and a trick to remembering that is to remember the following phrase: the way to a man’s heart is through his pelvis!
Male vs Female Sacrum
The sacrum of the female is shorter, wider, and has a greater curve, whereas the male sacrum is thinner, longer, and is less curved. The coccyx bone of the male curves more toward the front of the body in comparison to the female’s coccyx.
Greater Sciatic Notch, Acetabula, and Ischial Tuberosities
- The greater sciatic notch is wider and shallower in the female pelvis as compared to the male pelvis.
- The acetabula (cup-like sockets that accept the head of the femur) are smaller and farther apart in females, whereas men have larger acetabula that are closer together.
- The ischial tuberosities of the pelvic outlet are farther apart, shorter, and pointed outwardly in the female pelvis, whereas the ischial tuberosities of the male pelvis are sharper, longer, and they point toward the body’s midline.
Obturator Foramen Differences in Males and Females
Obturator foramen (foramina = plural): Because the male pelvis is narrower and taller, the obturator foramina have a rounded look. In contrast, the obturator foramina in females have more of an oval shape, similar to an egg on its side.
Ventral Arc, Subpubic Concavity, and Ischiopubic Ramus
- Ventral arc: Females also have a pronounced ventral arc on the anterior surface of the pubis, located inferiorly, which is usually not a feature of the male pelvis.
- A subpubic concavity, which is a notch along the medial edge of the ischopubic ramus, is more pronounced in females after the onset of puberty.
- Pointed ischiopubic ramus: Finally, you have the medial aspect of the ischiopubic ramus. Again, medial is a directional term that means toward the body’s midline. Here, you’ll find that the ramus comes to pointed edge in females, while in males, it is more rounded.