I had a very productive session with a physiotherapist today, who made some really constructive and pragmatic points (for example, demonstrating quite simply and clearly that the curve on my corner-desk points the wrong way, and simply swapping to a mirrored desk could help hugely).
But one startling point she made while observing me; as a programmer, I move frequently between the keyboard (in my case a decent ergonomic split jobbie) and the mouse (now a shiny new "vertical" model) - code a few lines, use the mouse to click a few buttons, test a few things via the UI - rinse, repeat.
Sure, I use the keyboard shortcuts, but I would struggle to remember the hundreds of magic key-presses and "chords" that drive Visual Studio.
Very rarely do I use the numeric keypad. Heck, I also use a laptop, and the only time I find myself looking for Num Lock is when my password inexplicably doesn't work. Yet every time I move between keys and mouse I have to travel this pointless distance.
Lets not do that
Numeric keypads; absolutely useless. Underused, oversized, badly placed, and they don't agree with 'phones on which way the numbers should go.
She gave me a tip to simply try a keyboard without one, letting me have the mouse much closer. You can pick up a "Goldtouch" ergonomic keyboard (sans keypad) for about GBP25 at Amazon. This is so simple and so obvious that I'm just stunned that people insist on still including it, even on "ergonomic" keyboards. If it is so ergonomic, why is it causing unnecessary travel?!?!
If you want a keypad (and I do find them handy occasionally), then buy a USB keypad (like they sell for laptops) - roughly GBP10, and that is for the models that double as a handy USB hub. If you're right-handed, stick it on the left, or on the far side of the mouse - whichever you prefer and find most comfortable. Plus you can move it to either side if a "sinister" shows up at your desk.
Join the revolt! I invite you to ditch (or move) your keypad today!