The largest vertebrae are those that make up the low back. Why?

To answer this question, you can think of the spinal column as analogous to a stack of blocks, with each vertebra resting on top of the bone below it. Ask yourself - would the smallest block provide a stable foundation for progressively larger ones to rest on top? (I hope your answer is 'no'!) Add to this balancing act the fact that the spinal bones continually shift and move to accomodate forces that act upon the body; the vertebral column is not a static structure by any means.

The bones of the low back provide stability for the vertebrae (and head) to rest on top. In human movement, there is a stability-mobility balance of power that continually occurs and is ever-dynamic. Through the modulation of stability and mobility, our spines, and the rest of us, can move freely and comfortably, while we remain grounded.

Illustration (c)Anne Asher 2006 licensed to About.com

Below are some articles that can help you understand the anatomy of the low back and low back pain:

• The Low Back
• Low Back Pain and Tilted Pelvis
• The Low Back Curve
• L5-S1
• A Very Special Back Muscle
• Low Back Pain in Women
• Back Pain and Pregnancy