The Total Back Book (Click Here for more info):
The back is the one ofthe most complex and versatile parts of the human skeleton. The key to many of your vital functions (see box, right), it has great strength and flexibility. However, this means that great demands and stresses are placed on it during your daily activities, making it one of the most vulnerable parts of your skeleton. As many of you will already know, it is, therefore, an all-too-common site for aches and pains.
Pain is your body's way of telling you that something is wrong. When you have back pain, you experience a sensation generated by the brain in response to signals from pain receptors in your skin, organs, muscles, and other tissues. The intensity of the pain you feel is not due to the strength of such messages, but rather their number and frequency.
Pain messages are of two natures: acute and chronic. "Acute" travels at 10 meters (30 ft) per second, while "chronic" travels at only about 1 meter (3 ft) per second. Acute pain is the more intense of the two as more acute signals than chronic ones can be sent in the same length of time...
