We found out after a few years of side-lying computer experience that fingers and hands with advanced fibromyalgia can experience accelerating pain from keyboard use as well as mouse use. Using a Marble Mouse trackball helps a lot but pain dictated an arm sling hanging from the ceiling and a foam keyboard holder helped as well. Using lidocaine helped some, but the use of a Super Mini Bluetooth Wireless Keyboard, an X-keys® XK-4 Stick (the device in the picture, below), and a Switch-Adapted Mouse that has a jack for a left-click microswitch worked the best for pain reduction. The mouse is out of sight. It's only used at all to have something to plug our left-click microswitch into.
What is this Xkeys thing? A programmable tool for greater efficiency and ease of use with a computer.
•Four relegendable keys (but 8 key and 16 key versions are also available)
• Addressable blue backlighting for each key
•USB connection to computer or tablet
Perfect for adding a few control keys to a tight space. The XK-4 offers four programmable keys to trigger macros, shortcuts, and applications, select tools or open files or directories. The low profile, slim footprint fits nicely on a podium or under a monitor. The XK-4 provides a versatile control strip for any computer driven application. I like it best for drag, copy, and paste operations.

Xkeys and Marble Mouse and Super Mini Bluetooth Wireless Keyboard

Left-Click Microswitch Wrapped Up with Tape

Switch-Adapted Mouse Has Jack for Left-Click Microswitch