Time for a Stretch

As a music producer and pianist, I spend lots of time sitting at the keyboards (the musical one and the computer one).  For decades I have been using my hands and arms for many hours a day.  For the past few weeks, I have been experiencing severe pain in my left arm, undoubtedly the build up of years of overuse.  The muscles are so accustomed to being in a certain stance that they get frozen in that position.  Medical advisors and therapists have encouraged rest, but also lots of slow, gentle...