Old athletic injuries taught me the wisdom of what Cruiser shared -- exercise. Many activities, whether they are running or fiddling, excercise one set of opposing muscles to the exclusion of its "matched pair" (for instance, biceps/triceps or quads/hamstrings). The reason this leads to injusry is that the excercised half of the pairing remains shortened and "tugging" on joint and bone, thereby causing stress to the skeletal structure and joints -- not to mention that tightness of the exercised muscle itself.

One can usually deduce which half of a pairing they are overusing and come up with a suitable counter-exercise (as a potter -- always pushing inward -- I keep a set of weights in the shop and do "butterflies" to keep soreness out of my shoulders). Or, as Cruiser said, exercise the whole muscle group -- it will keep the pairings closer.

You may have to lay off and treat the inflamation for a time, but once you can start in again, remember that excercise will make the whole activity less effort as well.