Back Pain
Most back pain is acute, lasting from a few days to a few weeks. It is generally caused by muscle strain or muscle spasm. In addition, back pain may be caused by pinched nerves in the back or other neurological problems.
Self-Care
http://www.mayoclinic.com/health/back-pain/DS00171/DSECTION=1
http://www.webmd.com/back-pain/tc/Low-Back-Pain-Topic-Overview