I got these and found them to be great for both my carpal and cubital tunnel syndrome. They Velcro on tightly. My issues have resolved but I still use the one.

They are very comfortable. I am not sure how I have used PC desk chairs for decades without one.

BEAUTRIP Ergonomic Armrest Pads- Office Chair Arm Rest Cover Pillow ... https://www.amazon.com/BEAUTRIP-Ergonomic-Armrest-Office-Pillow/dp/B099WXC87S