Figuring out how to play correctly isn't easy and many professionals think it's just their bodies giving up on them when it's really the technique they are using. How many times have you seen musicians wearing wrist or elbow warmers? They are not wearing these because they are cool; they are wearing them because there is a problem. How many times have you seen a musician going through stretching exercises on or off stage? These are all signs that there are deeper problems. If you are playing correctly in most cases you don't need a regimen of stretching or therapeutic devices to be worn on your body.