Coccyx vs. Sacrum — What's the Difference?
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By Tayyaba Rehman — Updated on October 9, 2023
The coccyx, also known as the tailbone, is the small, triangular bone at the base of the spine. The sacrum is the larger, triangular bone above the coccyx, connecting the spine to the pelvis. Both are parts of the vertebral column.
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Difference Between Coccyx and Sacrum
Table of Contents
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Key Differences
Regarding pain or injury, the coccyx can be particularly sensitive. Falls or prolonged sitting might cause coccydynia, which is pain associated with the coccyx. The sacrum, while robust, can also be subject to fractures or pain, especially in conditions like sacroiliitis, which affects the sacroiliac joint.
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Tayyaba Rehman
Oct 09, 2023
The coccyx and sacrum are integral components of the human vertebral column. The coccyx, often termed the "tailbone," is the final segment of the vertebral column, comprising three to five fused vertebrae. In contrast, the sacrum is situated just above the coccyx and consists of five fused vertebrae.
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Oct 09, 2023
Both the coccyx and sacrum play significant roles in supporting the body. The coccyx serves as an attachment site for certain muscles, ligaments, and tendons, providing stability. On the other hand, the sacrum forms the back portion of the pelvis, interfacing with the hip bones to create the sacroiliac joints.
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Tayyaba Rehman
Oct 09, 2023
Both the coccyx and sacrum have evolutionary significance. The coccyx is a vestigial structure, a remnant of tail vertebrae from evolutionary ancestors. The sacrum, however, has evolved to be broader and more curved in humans, providing support for our bipedal posture.
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Tayyaba Rehman
Oct 09, 2023
Comparison Chart
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Evolutionary Significance
Vestigial remnant of tail vertebrae
Adapted for bipedal human posture
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Oct 09, 2023
Function
Attachment for muscles, tendons, ligaments
Forms back part of the pelvis, sacroiliac joint formation
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Tayyaba Rehman
Oct 09, 2023
Definitions
Coccyx
The coccyx is the small triangular bone at the base of the spine.
He bruised his coccyx during a fall.
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Tayyaba Rehman
Oct 09, 2023
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Sacrum
Sacrum forms the posterior wall of the pelvis.
The sacrum and iliac bones together form the sacroiliac joint.
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Oct 09, 2023
Coccyx
Coccyx is often referred to as the tailbone.
He felt pain in his coccyx, or tailbone, after sitting for hours.
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Tayyaba Rehman
Oct 09, 2023
Sacrum
The sacrum is a broad, triangular bone at the base of the spine above the coccyx.
She fractured her sacrum during a skiing accident.
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Oct 09, 2023
Coccyx
Coccyx comprises of three to five fused vertebrae.
Doctors confirmed there are four fused vertebrae in her coccyx.
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Oct 09, 2023
Sacrum
Sacrum consists of five fused vertebrae.
The five vertebrae of the sacrum fuse during early life.
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Oct 09, 2023
Coccyx
Coccyx serves as the terminal segment of the vertebral column.
She learned that the coccyx was the end part of the vertebral column.
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Oct 09, 2023
Sacrum
Sacrum is integral to bipedal human posture.
The curvature of the sacrum helps support our upright stance.
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Oct 09, 2023
Coccyx
Coccyx provides an attachment site for several anatomical structures.
Certain ligaments attach to the coccyx, giving stability.
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Oct 09, 2023
Sacrum
The sacrum (plural: sacra or sacrums), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1–S5) between ages 18 and 30.The sacrum situates at the upper, back part of the pelvic cavity, between the two wings of the pelvis. It forms joints with four other bones.
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May 24, 2018
Coccyx
The coccyx (plural: coccyges or coccyxes), commonly referred to as the tailbone, is the final segment of the vertebral column in all apes, and analogous structures in certain other mammals such as horses. In tailless primates (e.g.
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Sacrum
A triangular bone in the lower back formed from fused vertebrae and situated between the two hip bones of the pelvis.
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May 24, 2018
Coccyx
A small triangular bone at the base of the spinal column in humans and some apes, formed of fused vestigial vertebrae.
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May 24, 2018
Sacrum
A triangular bone made up of five fused vertebrae and forming the posterior section of the pelvis.
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May 24, 2018
Coccyx
A small triangular bone at the base of the spinal column in humans and other apes, consisting of several fused rudimentary vertebrae. Also called tailbone.
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May 24, 2018
Sacrum
(anatomy) A large triangular bone at the base of the spine, located between the two ilia (wings of the pelvis) and formed from vertebrae that fuse in adulthood.
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May 24, 2018
Coccyx
The final (bottom-most) fused vertebrae at the base of the spine, the tailbone.
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May 24, 2018
Sacrum
That part of the vertebral column which is directly connected with, or forms a part of, the pelvis.
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Coccyx
The end of the vertebral column beyond the sacrum in man and tailless monkeys. It is composed of several vertebræ more or less consolidated.
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May 24, 2018
Sacrum
Wedge-shaped bone consisting of five fused vertebrae forming the posterior part of the pelvis; its base connects with the lowest lumbar vertebra and its tip with the coccyx
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May 24, 2018
Sacrum
Sacrum plays a role in connecting the spine to the pelvis.
Without the sacrum, the spine wouldn't be connected to the pelvis.
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Oct 09, 2023
FAQs
Where is the sacrum located?
The sacrum is positioned above the coccyx, forming the back portion of the pelvis.
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Oct 09, 2023
Why is the coccyx called the tailbone?
It's a vestigial remnant of tail vertebrae from evolutionary ancestors.
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Oct 09, 2023
What is coccydynia?
Coccydynia refers to pain arising from the coccyx or tailbone area.
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Oct 09, 2023
Is sacroiliitis related to the sacrum?
Yes, sacroiliitis is an inflammation of the sacroiliac joint formed by the sacrum.
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Tayyaba Rehman
Oct 09, 2023
What's the coccyx?
The coccyx, or tailbone, is the small, triangular bone at the base of the spine.
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Tayyaba Rehman
Oct 09, 2023
Can you break your coccyx?
Yes, falls or impacts can lead to coccyx fractures or bruising.
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Oct 09, 2023
How can the coccyx be injured?
Commonly through falls, prolonged sitting, or direct trauma.
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Oct 09, 2023
What structures attach to the sacrum?
Ligaments, tendons, and muscles, especially those of the pelvis and lower back.
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Tayyaba Rehman
Oct 09, 2023
How many vertebrae make up the coccyx?
The coccyx comprises 3 to 5 fused vertebrae.
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Oct 09, 2023
What's the main function of the sacrum?
It provides support for bipedal posture and forms the posterior wall of the pelvis.
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Tayyaba Rehman
Oct 09, 2023
Are the coccyx and sacrum movable?
They're mostly fixed due to fused vertebrae, but slight movement is possible at their joints.
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Oct 09, 2023
How is the sacrum connected to the pelvis?
The sacrum forms the sacroiliac joints by interfacing with the hip bones.
![](webp/e71d67b1aba47c9e5bd8eb22e21c1ed5c3b8.webp)
Tayyaba Rehman
Oct 09, 2023
Why is the sacrum broader in humans?
It has evolved to support our upright, bipedal posture.
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Oct 09, 2023
Are the coccyx and sacrum unique to humans?
No, other vertebrates have them, but their shapes and functions might differ.
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Tayyaba Rehman
Oct 09, 2023
What connects the sacrum and coccyx?
The sacrococcygeal joint connects these two structures.
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Tayyaba Rehman
Oct 09, 2023
Author Spotlight
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Written by
Tayyaba RehmanTayyaba Rehman is a distinguished writer, currently serving as a primary contributor to askdifference.com. As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.