The Mouse

(Excerpted from the book, "(Amazon) It's Not Carpal Tunnel Syndrome: RSI Theory & Therapy for Computer Professionals")

Mice present an inevitable hazard because they require such fine and incessant positioning. Ironically (or is it?), it’s the fact that they are so ideally suited to the task of pointing that makes them so damaging. That’s because they get the job done with almost no motion whatsoever. For the user, however, this translates into static position and a constant pinching grasp. To combat this, we offer a combination of the same fundamentals that we recommend with keyboarding, and some specific ergonomic suggestions.

Use Your Arm Just as with the keyboard, try to use larger arm movements rather than twisting the wrist.

Straighten Your Wrist Make sure that the wrist is in line with the forearm and not bent up or down. If necessary, adjust your mouse tray or buy a new one. Particularly avoid an alignment that causes the pad of your hand to rest on the edge or corner of the work surface.

Stop Pinching Many people tend to hold the mouse with the tip of their thumb, clicking with the index finger. Instead, relax your thumb and let go of the "death grip." Try to simply rest your whole hand over the mouse and use both the index and middle fingers to click.

Mouse Trays Keyboard trays accommodate the mouse in one of two ways: some have one big flat surface for both the keyboard and mouse; others have a separate bracket attachment tray for the mouse. Ideally, the mouse should be at the same level as the keyboard, suggesting that one flat surface is preferred. With this configuration, you can put the whole tray at a slight negative angle (downward at the far edge) for the mouse as well, enabling you to keep your wrist straight. This single surface configuration also makes it easier to change the mouse from side to side to use with either hand, distributing the load between them. However, if you become accustomed to working with your keyboard at a significant negative angle, the mouse becomes a nuisance, sliding off all the time. Your only recourse if you do choose this type of keyboard tray is to arrange a platform for the mouse, propped up at the back with something like a small towel. A low-tech way to make the platform is to use ½" thick foam core board, available from a framing shop or art supply store, and tape it in position with strong tape.

Move the Mouse In If you don’t need the numeric keypad of your keyboard, install a brand of keyboard that does not have a keypad in it. Then you can bring the mouse closer to you, thereby relieving some of the stress on the arm that uses the mouse. If you have a keyboard tray with a separate mouse platform, you may be able to rotate the mouse platform in over the top of the numeric keypad.

Connect Two Mice at Once With a device called a Y-Mouse^TM Dual Mouse Adapter, you can have two different types of mice—as long as they can work with the same software driver—connected at the same time. You might use a regular mouse for graphics and use the trackball, which requires less pinching, for all other tasks. Alternating between them reduces the monotonous position. It is about $45 because it includes some electronics.

Swap Sides Consider switching the mouse from side to side every few weeks.

We offer this recommendation with a healthy dose of caution: use this technique only after you’ve learned to manage your body’s response to RSI. Simply switching hands to try to escape from symptoms that you haven’t gained any control over will only lead to more damage.

It’s not easy getting started with the mouse on the "wrong" side, but with practice, you’ll be just as efficient. Remember, don’t push either side to the point of fatigue. The idea is to distribute the workload, not to cause injury to both sides!

Which Mouse is the Best? No mouse is a "good" mouse—they all cause overuse of different groups of muscles. The only mouse that won’t hurt you is one that you don’t use to do repetitive tasks! People have varying success with alternate mouse styles such as trackballs, pens, and touchpads, and you should certainly investigate them if you have serious problems using a mouse. Even some conventional mice simply have a better shape that reduces the pinching action. Trackballs can also reduce the pinching action, but will initially be awkward for high-power word processing or programming. Pressure sensitive touch pads or graphics tablets are an option for some users. These are built into many laptop computers, but can be purchased separately. With these devices, you use either your fingertip or a pen on a surface that reads your position.

Evaluating Mice Your first criteria in evaluating a new mouse will probably be whether you can use it productively, irrespective of any comfort considerations. For instance, you may find a trackball unsuited to graphics work. Only after you find a mouse that works will you try to judge whether it is less stressful. This is a difficult judgment to make since the mere act of changing to a different mouse, aside from of the relative long term merits of the two styles, might cause more discomfort as you concentrate on the new techniques. If so, you may not give it a fair chance. Conversely, it’s possible that the new one will feel better initially because it uses different muscles. Then, as your capacity is exceeded on these muscles, your symptoms recur.

So, unless you have a compelling reason to change the type of mouse, get a high quality, conventional mouse, sized comfortably for your hand&ldots; make sure it is properly situated&ldots; and learn to use it as we’ve described.