Quote:

One of my perfessers wrote a book on hand calisthenics. He stressed the safety factor: NEVER NEVER use any kind of warmup or stretching that involves using one hand to stretch the other, or any kind of mechanical stretching device.




I can see why he would give that advice - because it is so easy to make a mistake regarding how much to stretch. Many people have the wrong notion that "more is better", and "no pain no gain", but overdoing a stretch (easy to do when one hand is placing force on the tendons and ligaments) can probably cause permanent damage - as your case in point. Though I'm wondering why Shumann was doing such a dangerous warmup without regard for what to me is a somewhat self-evident danger, and what exact damage he did to ruin his hand ? (excuse my ignorance - Schumann's the piano player that wrote those famous practice books, right ? - I know, I know, - I should google it.)