Difference Between Male and Female Sacrum

The key difference between male and female sacrum is that the male sacrum is taller and narrower while female sacrum is shorter and wider.

The sacrum is one of the vertebrae of our vertebral column, which is at the bottom of the backbone. Accordingly, it locates between the L5 vertebra and coccyx vertebra in the vertebral column. Also, it is attached with right and left iliac bones of the hip bone and contributes to the formation of the pelvis. Structurally, the sacrum is a triangular-shape larger bone comprising of five fused segments/small bones. The sacrum is important for several major functions including weight-bearing, walking, standing and sitting, etc. Structurally, sacrum differs between male and females (sexual dimorphism). Therefore, this article intends to discuss the difference between male and female sacrum.

CONTENTS

1. Overview and Key Difference
2. What is Male Sacrum
3. What is Female Sacrum
4. Similarities Between Male and Female Sacrum
5. Side by Side Comparison – Male vs Female Sacrum in Tabular Form
6. Summary

What is Male Sacrum?

The male sacrum is narrower and taller. It is a part of the pelvis and affects the shapes of the pelvis inlet and outlet. Therefore, due to the structure of the sacrum and its curvature, pelvic inlet of the males is heart-shaped while the pelvic outlet is narrower.

Apart from that, pubic arch forms an angle closer to 60⁰ in males. In male pelvises, the sacrum is more curved and tends to impinge upon the space of the pubic outlet.

What is Female Sacrum?

The female sacrum is shorter and wider. Furthermore, the curvature of the female sacrum is very low. Due to these structural features of the female sacrum and its involvement in the formation of the pelvis, the shapes of the pelvic inlet and outlet of females differ from that of the males. Accordingly, female pelvic inlet is oval shaped while their pelvic outlet is wider than males.

Furthermore, the upper half of the sacrum is nearly straight. Overall sacrum in female pelvises tends to be less curved than in males. Not only that, but the sacrum is also directed more obliquely backward in order to increase the size of the pelvic cavity in females. In addition, pubic arch forms an angle closer to 90⁰. Structurally, the lower half of the sacrum exhibits a greater angle with the upper.

What are the Similarities Between Male and Female Sacrum?

• Both male and female sacrum are important for weight bearing, walking, standing and sitting.
• Also, both are located in between L5 vertebra and coccyx.
• Furthermore, both are attached to the hip bone and reside in the bottom of the backbone.

What is the Difference Between Male and Female Sacrum?

Sacrum shows sexual dimorphism. Hence, male and female sacrum differ from each other structurally. Accordingly, the male sacrum is taller and narrower. On the other hand, the female sacrum is shorter and wider. Therefore, this is the key difference between male and female sacrum. Furthermore, the curvature of the sacrum is higher in males than the females. Thus, it is also a significant difference between male and female sacrum.

Moreover, male pelvic inlet is heart-shaped while female pelvic inlet is oval shaped. When considering the pelvic outlet, it is narrower in males while it is wider in females. Hence, it is another difference between male and female sacrum.

The below infographic presents more details on the difference between male and female sacrum.

Summary – Male vs Female Sacrum

The sacrum is one of the vertebrae in our vertebral column that attached to the right and left iliac bones of the hip bone. Moreover, it is shaped differently in males and females. Female sacrum is shorter and wider. On the other hand, the male sacrum is taller and narrower. Not only that, female sacrum shows a less curvature while male sacrum shows a greater curvature. Thus, this is the summary of the difference between male and female sacrum.

Reference:

1. “Sacrum Anatomy, Area & Definition | Body Maps.” Healthline, Healthline Media. Available here  
2. “Sacrum.” Wikipedia, Wikimedia Foundation, 11 Jan. 2019. Available here  

Image Courtesy:

1.”10819140914″ by University of Liverpool Faculty of Health & Life Sciences (CC BY-SA 2.0) via Flickr
2.”809 Male Female Pelvic Girdle”By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013., (CC BY 3.0) via Commons Wikimedia