"https://evoluent.com/ I've been using an Evoluent vertical mouse for several years now due to wrist/forearm pain.   It's fully configurable/customizable for each mouse button.  It's available in left hand/right hand, wired/wireless/bluetooth, regular/small size, etc.   It does take some time to get used to and sometimes is difficult to operate a traditional mouse now.   Cost is around $100 give or take depending on model. "