My first computer was an XT clone, and I think I acquired it in 1985 or thereabouts. So far as I recall, it came with a mouse. So I’ve been using a mouse for about 35 years, without ill effects. Yet just recently, I started having pain in my right hand, especially when clenching. I started to feel it mostly at night, in bed, so it took a couple of weeks for the truth to dawn – it was being caused (at least to some extent) by the curvature of my fingers over the mouse.
The solution, at least partially, has been to use an ergonomic mouse. We happened to have one, acquired from Officeworks a few months ago, and it certainly has helped with the issue. It’s cleverly designed although slightly more cumbersome than a traditional mouse, but this has been a small price to pay. I’ve combined this with flexing my hand more often, and trying to take it off the mouse except when actually using the device.
I’m at a loss to understand why the issue with my hand has only just arisen, although I admit there is a little joint pain developing in one finger (part of the aging process, I guess). But overall, things are now slowly improving.
Musings and Mutterings 
I sympathise with this sign of age, and have some second hand (pun) knowledge of it— a close friend is a hand therapist at The Alfred. However I am a victim of the great world conspiracy to punish left handers. Left in Latin is appropriately “sinister.” .
The sinister are lucky if they find a symmetric mouse to relieve the pain, but Logitec has some specialised options.
See also: 7 Reasons You Should Consider a Left-Handed Mouse – Even if You’re Right-Handed https://bit.ly/3xRw514
LikeLike