My personal experience is different. I developed strain from a bog standard, low profile office mouse, by turning my right (mouse) hand to be relatively flat, with the strain being rotating the thumb side down. Using a Kinesis DXT2 mouse resolved it relatively quickly. It's vertical, looks a bit like a sail, and after a brief period getting used to it, I found it very easy and very accurate to use, a bit like holding a pen. I should note that it was odd enough that I really had to have a spare normal mouse for when anyone else wanted to use my computer (during code reviews, etc.), that was quite funny.
I haven't actually even used it in years (lost during an office move), but now I instinctively use a regular mouse with my hand at least at a 45 degree angle to the table, instead of parallel with it, and I still have no strain. I think I'd have trouble doing that with a bog standard low profile office mouse, but my old Logitech mouse is chunky enough that it works for me without thinking about it.
My elbow was always on the armrest, but it was only after using a vertical mouse that I trained myself to not strain myself.
I haven't actually even used it in years (lost during an office move), but now I instinctively use a regular mouse with my hand at least at a 45 degree angle to the table, instead of parallel with it, and I still have no strain. I think I'd have trouble doing that with a bog standard low profile office mouse, but my old Logitech mouse is chunky enough that it works for me without thinking about it.
My elbow was always on the armrest, but it was only after using a vertical mouse that I trained myself to not strain myself.