Edit: Because I have no manners, sorry you’re having these issues!
Yes, we met with researchers at the Hospital for Special Surgery here in NYC. The name sounds scary! But it’s a research hospital and that, not surgery or injury, was our interest. They published a study on wrist motion where they were able to measure the different ways the wrist can move in everyday activities. The motions they documented are similar to those used in guitar picking. It’s on our hard drives, and we’ll edit it, when we figure out how to clone ourselves to add more hours into the day.
I had some mild forearm strain maybe fifteen years ago when I was trying to figure out how two-way pickslanting worked and came home from work every day and did that every night for hours. What is “that” you ask? Good question, I didn’t really know. I probably just repeated scales forever. I didn’t really know what I was looking for, or what I was doing to get there. I stopped playing for a week or so, and the strain went away. That’s about it from guitar playing. More recently, video editing has been a real killer - thousands of mouse clicks and drags on a trackpad will destroy forearms. I got an ergonomic mouse and that’s much better now.
In general, I don’t think marathon guitar practice is how physical skill learning really works best. And over the years I have developed what amounts to my own strategies for trial and error which rely more on lots of little tests with downtime in between. As a result, I tend not to play huge amounts, and when I do, it’s very start and stop because I’m always filming myself. It’s like playing for a few minutes, then watching footage, then playing. Then getting a sandwich. And so on.
When you pile on the big reps, I assume it’s because it’s not working. That means you are doing it wrong, so what’s the point in repeating it? Instead I think motor learning requires lots of tests and changes and more tests, with downtime in between trying to find what works and then trying to replicate it a few minutes later. In other words, it’s the changes that you yourself make to your form in between the repeats that are really making the progress. And/or the sheer randomness of picking up the guitar and doing it right by accident, once, and then trying to figure out what you did. As things start to come together, progress happens by putting the guitar down, coming back a few minutes later, and doing it again. The recall. That’s what makes it permanent.
People in music school who have no choice but to practice really long, complicated things for hours that kill their fretting hand, I feel for them, truly. I don’t know any way around that. Others who have lived that life will know much more than I. But from a technique learning perspective, that process boils down to sometimes very brief flashes of insight, and in my experience hammering away for hours is not really how you get there.
