Reprinted from The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
From Tracee Cornforth, former About.com Guide
Updated December 02, 2003
About.com Health's Disease and Condition content is reviewed by the Medical Review Board
Reprinted from The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)