Back pain is a common problem. According to the World Health Organization, various diseases of the musculoskeletal system affect almost 80 percent of the population. Here is how your sleeping position can change your back pain. Everyone at least once in their life has dealt with back pain. "Computers, office work, and other joys of modern society affect human health,” says neuroscientist Matthew Walker, director of the Center for Science of Human Sleep at the University of California at Berkeley. But there is another reason for back pain, which few people have thought of...