Several years ago I came across a Mayo Clinic study that was quite eye opening. In the study, they examined the files of over 142,000 of their patients to determine what the most common health problems were among them. The patients were of various ages and were split 53% to 47%, women to men.
What they found was that 57.5% of these patients had problems affecting their musculoskeletal system. "Arthritis and joint disorders" came in at 33.6% and "back problems" came in at 23.9%.