From Aaron's Schwenfeier's blog:

http://aaronschwenzfeier.blogspot.com/2008/06/breathing-and-spine.html

This is how professional interaction should work. Aaron and I don't agree on everything but we continue the discussion and don't get mired in the differences. In the end we agree on FAR more than we disagree. Plus he has some great information - like this:

"The lumber spine has greater flexion/extension range-of-motion (ROM) based on disc height and spinous processes which project almost straight posteriorly, while the thoracic discs are smaller and the spinous processes project more inferiorly, which decreases flexion/extension ROM. The architecture of the thoracic spine lends itself to greater rotational ROM based on the position of facet joints, and the lumbar spine's facet joints decrease rotational ROM when compared to the thoracic vertebrae. (check out a good anatomy/biomechanics text)"

And this:

"When we have good diaphragmatic breathing, the diaphragm (again, refer to a good functional anatomy text) pushes down on the viscera. This "pushing" down creates pressure on the pelvic floor, which creates reflexive activity of the deep abdominal muscles... (something to think about.) From this we potentially improve:
1. Lumbar spine muscle function and control leading to:
2. Improved hip and lower body function
3. Increased thoracic spine ROM leading to:
4. Improve scapula and glenohumeral function and ROM
5. Improved function of all muscles, especially scapular, shoulder, and hip muscles
6. Improved movement efficiency."

Great information!