I'm not endorsing the one above, just showing what it looks like. The one I had from the late 90s was wired, with a big roller at the tip instead of it being optical.
The main thing is that when you hold a pen, your hand is more up and down rather than flat to the surface of the table, like when you're holding a mouse. Having it up and down is a more natural position for the hand relative to your body and doesn't force it to be twisted away from the body so that I could hold the mouse. That twist was was pinched my nerve for me.
https://ergonomictrends.com/wp-content/uploads/2019/08/pen-m...
I'm not endorsing the one above, just showing what it looks like. The one I had from the late 90s was wired, with a big roller at the tip instead of it being optical.
The main thing is that when you hold a pen, your hand is more up and down rather than flat to the surface of the table, like when you're holding a mouse. Having it up and down is a more natural position for the hand relative to your body and doesn't force it to be twisted away from the body so that I could hold the mouse. That twist was was pinched my nerve for me.