Also one quick tip about hand health. While choosing a lower APM character might be a way to do some hand stress offloading, the peaks in this games execution aren't so high that they might inevitably lead to injury (like some suspect Melee fox is). This might seem counter intuitive, but practicing more (in a specific way) can probably do more for your hand health than character selection.
When you practice solo, either movement or combos/punish game etc. you have to be paying attention to your hands. When you practice solo you can develop good habits of stretching frequently(at the start of your play session), making sure your grip is relaxed, not pressing buttons too hard. Your button presses should be fast and precise, but that's doesn't mean your muscles and tendons should be working that hard.
In set play and at tournaments, and even during friendlies or on net play, our brain is so focused on the match and adaptation that there is no real room for noticing hand position or tension levels. I've seen way too many players who think that strangling their controllers with a death grip will make them play better when it comes to a high pressure match. In order to avoid this natural and physically harmful tensing up of our hands during tourney, we need to develop good hand health habits out of competitive settings so that they happen automatically.
I have a post it note on my home set up, right on the bottom of the monitor. In red sharpie it says this:
STRETCH FIRST
KEEP HANDS LOOSE
TAKE BREAKS
I would recommend something similar to anyone who takes this game a bit seriously.
This isn't applicable to everyone, and I'm not a medical professional so don't consider doing this without consulting a doctor first, but when I saw a hand specialist she recommended that I sometimes take an NSAID (Aleve, Motrin, Asprin, Advil, etc.) a long practice session or smash-fest. Inflammation isn't just a symptom on hand pain or repetitive stress injuries, but is also one of the leading causes these types of injuries. By taking an anti inflammatory before pain set in from heavy play, it is possible that one might reduce the severity/occurrence of gaming related hand injury before it happens. Again I must say the above is not medical advice, and I am not telling anyone to pop pills to smash. Even OTC pain meds have lots of risks. This is just something you might want to discuss with a doctor if you are worried about your hands.