Why this helps
The standard mouse design puts all the clicking workload on your index and middle fingers. For people with arthritis, repetitive strain injury (RSI), carpal tunnel syndrome, or any condition that causes joint pain in the fingers, hundreds of clicks per hour on those two fingers can become genuinely painful. The thumb, by contrast, is a stronger digit with a different range of motion, and the side buttons on most mice require less force to press than the primary buttons.
By remapping your left click to one side button and your right click to the other, you shift the repetitive clicking from your weaker, painful fingers to your thumb. Your index and middle fingers rest on top of the mouse without any clicking duty. The original left and right buttons still function normally for moments when you want to use them — but the constant clicking moves to your thumb.
Important: If you override the function of your original left and right click buttons (for example, assigning them to keyboard shortcuts instead), those buttons will perform the new action rather than their default. Plan your layout accordingly. For most arthritis setups, you'll want to leave the original buttons as-is and simply add side button mappings.
Watch the setup
Here's a walkthrough showing exactly how to configure this in MouseKey:
Step-by-step setup
Install MouseKey
Download MouseKey from the Microsoft Store. It installs in seconds and runs from the system tray.
Add your back side button
Click the + button to add a new action slot. MouseKey will ask you to press the mouse button you want to configure. Press your back side button (the one closest to you). Then select "Left Click" from the action list. This makes your back side button act as a left click.
Add your forward side button
Add another action slot and press your forward side button (the one farther from you). Select "Right Click" from the action list. Now your forward side button acts as a right click.
Rest your fingers
That's it. Your thumb now handles all primary clicking. Your index and middle fingers can rest on top of the mouse without bearing any clicking load. MouseKey runs in the system tray — minimize it and go about your day.
Going further with cadences
Since each side button now supports up to 6 actions via click cadences, you can stack additional shortcuts on the same buttons. Single click your back side button for left click. Double click it for copy. Triple click for paste. You get the ergonomic benefit of thumb-based clicking plus the productivity benefit of instant shortcuts — all without your index fingers touching a button.
For a full guide on how cadences work, read One Button, Five Shortcuts or watch the demo video.
Choosing the right mouse
Any mouse with at least two side buttons will work for this setup. You don't need an ergonomic mouse or a specific brand — MouseKey works at the system level with any mouse that Windows can detect. That said, if you're shopping specifically for comfort, look for a mouse with side buttons that are easy to reach without squeezing the mouse body. Larger mice with well-spaced side buttons tend to be easier on arthritic hands.
MouseKey doesn't require Logitech G Hub, Razer Synapse, Corsair iCUE, or any manufacturer software. If your mouse has side buttons that Windows recognizes, MouseKey can remap them.
Other ways MouseKey helps with accessibility
Beyond button reassignment, MouseKey offers several features that reduce the physical demands of using a mouse:
- Click cadences let you consolidate many keyboard shortcuts onto your mouse, reducing how often you need to reach across the keyboard
- Hold actions give you a sixth action slot triggered by holding a button for 2 seconds — useful for actions you want deliberate access to
- Timed macros let you record multi-step keyboard sequences and replay them from a single mouse press, eliminating repetitive keyboard work
- Button disabling lets you turn off buttons you keep hitting by accident, reducing unintended clicks and the frustration of correcting them
- Customizable disable toggle lets you choose which button turns MouseKey on and off, so you're not forced to use a specific button that might be uncomfortable
It takes 60 seconds
This entire setup — installing MouseKey, mapping both side buttons, and starting to use your thumb for clicking — takes about a minute. If clicking is causing you pain, it's worth trying. The change can be reversed just as quickly if it doesn't work for you, and MouseKey can be toggled off at any time by holding your chosen disable button for 2 seconds to return everything to normal.
Get MouseKey
Remap left and right click to your side buttons. Reduce finger pain. Works with any mouse.
