Title

Modern Medical Consequences of the Ancient Evolution of a Long, Flexible Lumbar Spine.

Document Type

Article

Publication Date

9-1-2019

Abstract

Modern human bipedality is unique and requires lumbar lordosis, whereas chimpanzees, our closest relatives, have short lumbar spines rendering them incapable of lordosis. To facilitate lordosis, humans have longer lumbar spines, greater lumbosacral angle, dorsally wedged lumbar vertebral bodies, and lumbar zygapophyseal joints with both increasingly coronal orientation and further caudal interfacet distances. These features limit modern lower lumbar spine and lumbosacral joint ailments, albeit imperfectly. The more coronal zygapophyseal orientation limits spondylolisthesis, while increasing interfacet distance may limit spondylolysis. Common back pain, particularly in people who are obese or pregnant, may result from increased lumbar lordosis, causing additional mass transfer through the zygapophyseal joints rather than vertebral bodies. Reduction in lumbar lordosis, such as in flatback syndrome from decreased lumbosacral angle, can also cause back pain. Human lumbar lordosis is necessary for placing the trunk atop the pelvis and presents a balancing act not required of our closest primate relatives.

Publication Title

The Journal of the American Osteopathic Association

Volume

119

Issue

9

First Page

622

Last Page

630

PubMed ID

31449308

Comments

This article was published in The Journal of the American Osteopathic Association, Volume 119, Issue 9, pages 622-630.

The published version is available at https://doi.org/10.7556/jaoa.2019.105.

Copyright © 2019 American Osteopathic Association.

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