If you’re sitting at your computer (if you’re on your phone, peek away for a second), what type of keyboard are you using? The probability is far greater that you have a full-sized keyboard; that is a keyboard with the number pad on the right. Every computer that I’ve ever been issued at every job has come with a full-sized keyboard. My last development computer came with a beautiful DAS keyboard, of course with a numeric keypad. In part four of 5 Risky Ergonomic Practices by Programmers (& Heavy Computer Users Too!) I’m going to rant about keyboards and mice!
I think that from the intro I made it clear that I don’t think much of full-sized keyboards. Unless you deal with numbers pretty much all of the time, you never use your mouse, or you like to use your keyboard when feeding your gaming addiction, full-sized keyboards pretty much suck! In my opinion of course. Disclaimer: I don’t think my colleagues at ergonomicsHelp.com would word it quite that way… In our experience completing office ergonomic assessments, around 90% of right shoulder discomfort is related to full-sized keyboard use! Anyway, the simple reason why I don’t like full-sized keyboards is because they force a right-handed person (I prefer to mouse with my right hand) to overextend their arm to reach the mouse. So if you never use your mouse (ie you live in a linux terminal and code in VIM – don’t worry if you have no idea what I’m talking about) then my tip to you is make sure you have a keyboard that is comfortable for you. A hack to this would simply switching to left handed mousing. Let’s illustrate the problem with right handed mousing on a full-sized keyboards using one of our trusty ergonomicsHelp dummys.
The Comfort Zone
If you follow our blog, you’ve likely read some of Darcie’s articles talking about neutral posture. If not, check out: How To Set-up Your Workstation For Sitting or Standing. When sitting at your desk, with your arms to your side and your shoulders relaxed, position your elbows at approximately 90 degrees next to your torso with your hands directly in front of you. This is what we call neutral elbow posture. Now taking a bird’s eye view at our dummy, we can illustrate what I mean by the comfort zone.
The green area in the diagram above, the comfort zone, is the area which is in the dummy’s direct/most convenient reach when assuming a neutral elbow posture. As soon as you move away from this area, more reaching is required. Ergonomic risk for discomfort increases the farther you get away from the this neutral area. Lets take a look at the same dummy but this time with a full-sized keyboard.
Due to the number pad extending to the right of the user (the dummy in this instance), the mouse is positioned way off to the right, well outside of the comfort zone and onto the edge of the danger zone (Yes Kenny Loggins fans, I went there). Prolonged over reaching postures can lead to numerous upper extremity problems including shoulder, elbow, and wrist discomfort. Now lets compare this scenario with the compact keyboard.
Since the compact keyboard is symmetrical and has a smaller footprint, the mouse is positioned within the comfort zone, reducing ergonomic risk. As I mentioned before, this is key for those of you that like to mouse with your right hand. Obviously if you’re comfortable with your left hand, a quick fix would be to switch to left hand mousing! You might be thinking well what if I need the number pad and I have a compact keyboard? Take a look at a usb numeric keypad or the Evoluent Mouse Friendly Keyboard.