Humbly, respectfully and possibly for the first time ever, I’m not in complete agreement with you, WordMan. I hope it doesn’t lead to pistols at dawn.
Here’s where I’m in agreement - this is a question for your teacher (There is a teacher involved in here somewhere, isn’t there?), your massage therapist or your physiotherapist. Someone trained who understands that musicians are highly specialized, hyper-coordinated athletes who have developed a level of dexterity mere mortals only dream of. Someone who gets that 90% of what you do as a musician involves tendons and ligaments, which behave in a different manner than muscles.
It isn’t a question that is best asked on the internet. I’m a nice guy, and my heart is pure, most of the time, but I can’t see your hands from here. You’re also very nice, and I’m sure your heart is pure, too, but I have no idea what your work habits are like and whether you are the type of person who will take my most ergonomically sound advice and do a Schumann on yourself. So I’m going to confine myself to the most general of advice and point you toward a couple of things but I’d be ever so much happier if you saw a living, breathing, trained human who is physically present, preferrabley within arm’s reach, if you really want to stretch things.
Where we’re not in accord, WordMan, is in your thinking that stretches are a recipe for tendon, muscle and joint problems. Some of them are, but some of them are meant to relax a body part that’s working at its maximum, and balancing the stress of practice with some gentle treatment is a good idea.
Also, I have to caution any musician who uses practice alone to improve the condition of his hands - if I may be permitted to describe musicians as athletes (a controversial metaphor, as many musicians and teachers immediately react in a negative way to that association.), musicians have a poor track record in terms of sticking to a fixed number of reps and then leaving it for the day. Indeed, many musicians use a formula that roughly corresponds to “I’ll keep doing it until I get it right.”, which can lead to real problems.
The other thing about repetition without supervision is this - what if there’s a more ergonomic way to do the riff that the student hasn’t found yet? Even assuming that it’s the ideal fingering for the student*, ten minutes of the teacher saying
makes a tremendous difference to what the student is practicing. It’s a different approach to repetition.
Repetition of an ergonomically unsound approach leads to problems. Ten repetitions of an ergonomically sound approach does more benefit than a hundred repetitions of an unsound approach. An unsound approach can do more harm than good. How can you tell if you’re using a sound or an unsound approach? In my opinion, the best way is with a teacher. A massage therapist or physiotherapist can tell if your hands are being inefficiently used from how it ‘feels’ to them, but I find it’s better to use your hands efficiently from the get-go.
And with that, I’ve used my hour of computer time for a Sunday day time…
*Please, pardon my bolding, but this is a subject which makes me cranky - I don’t give a sh!t how Jimmy Page played it! Did you chop his hands off and transplant them on the ends of your arms? No? Then let’s find what’s best for your hands, even if it means playing it in a different place than you saw on the YouTube video. Do you think Jimmy Page would slavishly copy the way another guitarist plays a lick, or do you think he’d find the easiest possible way to do the same thing? The way that suited his hands best? I submit that he’d find the easiest way for his hands. If I ever get the privilege of speaking to him face to face, I promise I will ask him.