Rotator cuff tear
Credit: Pali Rao / Getty Images

About 50 percent of people over the age of 65 have some kind of rotator cuff tearing, and it's seen by many experts as a natural part of aging. Painful tears can sometimes be addressed with physical therapy, but if surgery is required, it is an operation with a fairly high success rate. 

The Fix: Working on the muscles around the shoulder is just as important as working on the muscles around the rotator cuff to prevent rotator cuff tears. Try cable-strengthening exercises, like rows.