Mouse & Pointing-Device Ergonomics

computer mouse ergonomicsMouse ergonomics is rapidly evolving as new pointing devices replace the first generation of computer navigation tools.

While keyboards have been around since the age of typewriters and early computers, mice and other pointing devices are relatively new. Made necessary by the introduction of graphical computer interfaces, these gadgets convert your hand movements into an electronic signal that tells your computer to move a cursor around your screen. This direct and intuitive connection with your computer revolutionized office work — and created a slew of new ergonomic considerations.

Pointing-Device Options

2000px-Mouse-cursor-hand-pointer.svgUntil recently, the mouse was the main pointing device for most computer work. Now, with the introduction of touchscreens, touchpads, and other alternative pointing options on office computers, we’re rapidly moving from the age of “point and click” to an era of “swipe and flick.”

For years, it was safe to assume that most office computers used a mouse as their main pointing device. Not any more. Here’s a quick overview of the most common pointing devices that you are likely to encounter in the near future.

Mouse

The modern mouse has evolved from a clunky contraption that awkwardly rolled around your mouse pad on a ball (and which gathered a surprising amount of lint) to a sleek, stylish, optically controlled ergonomic device that glides effortlessly across your desktop and gives you seemingly endless options for clicking and scrolling.

Vertical Mouse

vertical mouseA vertical mouse keeps you from rotating your palm downward to reach your mouse, reducing strain on your wrist and arm. Vertical mice come in two main styles. The first looks like a mouse that has simply been turned on its side. These mice feature slightly different contours to support your hand’s sideways position but otherwise operate much like a normal mouse. Other vertical mice look like a joystick that you wrap your fingers around and which you operate with controls on the side and top of the joystick handle.

Trackball

trackball mouseYou control a trackball, also known as a roller ball, by rolling a ball with your finger, thumb, or whole hand. It takes up less room on your desktop than a mouse and gives you more cursor control options. For example, if you routinely scroll across a large monitor, a trackball lets you keep rolling continuously across the whole screen without having to lift and reposition it, as you would with a mouse. Trackballs are typically used on a desktop but also come in hand-held models.

Joystick

pointing stick / laptop A true joystick is a lever control that moves in relation to a fixed base (unlike a joystick-style vertical mouse, which is fixed in position). The most common joystick control that you’ll see in the office is the trackpoint, sometimes called a pointing stick, a small eraser-like nub located between the G, H, and B keys on some laptop keyboards.

Touchpad

touchpadWith a touchpad, you run your fingers over a flat, touch-sensitive surface to move your cursor and execute commands. The touch pad has largely replaced the trackpoint on most laptops now, and touch pads are increasingly common on desktops, as a stand-alone mouse replacement or as a built-in feature on a keyboard.

Touchscreen

touch screenTouchscreens were first widely adopted with the introduction of the iPhone in 2007; they came to desktop computers with the introduction of Windows 8 in 2012. This now-familiar interface lets you tap, slide, and swipe directly on your screen. A touchscreen interface may be better suited for mobile devices and other situations in which the screen is horizontal, since reaching out for a vertical screen for long periods can cause arm fatigue.

The Future of Pointing

Clever hackers and innovative product designers are bringing us closer every day to the futuristic, touch-free interface that Tom Cruise operated in the movie “Minority Report.” Hackers have already turned Microsoft’s Kinect game controller into a pointing device that you can operate by nodding your Minority Report computer interfacehead and winking. Glove-based mouse replacements have been around for years, used mostly in gaming applications. Manufacturers like Leap Motion have introduced sensor-based pointing interfaces that let you gesture with your fingers to do mouse-like actions without ever touching any hardware. Thalmic Labs makes the Myo, a pointing device that wraps around your forearm and uses electromyography and sensors to let you operate your computer by making gestures with your hand. Voice-operated mice can translate your voice commands into cursor movements. A Silicon Valley start-up called Meta is developing a holographic “augmented reality” system that will let you turn any flat surface in your environment into a touchable interface. And it’s safe to say that engineers and product designers will keep on figuring out nifty new ways for us to interact with our computers.

Principles-Based Pointing-Device Ergonomics

Given this ongoing proliferation of pointing possibilities, taking a principles-based approach to pointing-device ergonomics makes a lot of sense. The variety of pointing devices available means that it is difficult to anticipate and address all of the details of the ergonomic situation for any one pointing-device.

Also, research shows that depending on your job, your age, your gender, other demographic factors, and personal preferences, you may favor one pointing device over another. And new pointing devices are constantly being introduced, and good advice about specific ergonomic practices for these new devices typically lags years behind their introduction. If you’re ever in doubt about how to assess your pointing-device ergonomic situation, get back to the basics, the ergonomics principles.

Neutral Posture

shutterstock_164972807You should be able to operate your pointing device with a straight, loose wrist and with your fingers, hand, wrist, and forearm all lined up in a neutral, relaxed position (just as with your keyboard). Your pointing device should be positioned so that your shoulder and upper arm also stay in a neutral position. If your upper arm is positioned awkwardly, you may have to move more at your wrist, a situation you always want to avoid. Instead, you want to position your pointing device so that its movement is initiated from your freely moving elbow.

No Reaching

mouse shoulderYou never want to have to reach for your pointing device. Reaching even slightly forward or to the side can set off a cascade of postural adaptations that pull your torso and shoulders forward, culminating in the dreaded “mouse shoulder” that I see every day in my massage practice. To avoid this, make sure that your desk surface or keyboard tray is wide enough to accommodate both your keyboard and your pointing device as close together as possible.

If you don’t use a numeric keypad in your job, make sure that your keyboard omits the extra 10-key layout. This lets you position your pointing device closer to the midline of both your keyboard and your body, reducing the amount of sideways reaching you have to do.

Proper Height

Generally, your pointing device should be at the same height as your keyboard. Some ergonomic articles advise positioning your mouse or other pointing device above your keyboard, to keep it centered in front of your body. There are two faults in this advice. First, it is hard to find the special gear that lets you position your pointing device like this. Also, positioning it this way requires you to constantly elevate your arm and shoulder. Still, as in many ergonomic decisions, personal preference can trump advice from any camp; if in doubt, use the set-up that is most comfortable for you.

No Pressure Points

computer mouse wrist restYou should be able to gently drape your hand over your pointing device, gripping it so that you can comfortably reach all of the controls. If you use a mouse or similar pointing device, it should fit the contours of your hand. If you use a trackpad, you should be able to reach it without bumping into the edge of your desk or any other obstructions. If you use a conventional mouse, a wrist rest can keep your forearm from pressing into your desktop.

No Excessive Motion

If you use a mouse or a vertical mouse, it should glide smoothly and easily over your work surface. Depending on your set-up, you may want to use a cordless model so that you don’t have to drag the cord around with the mouse. Your fingers should drape easily over your mouse and be positioned so that you don’t have to elevate them or otherwise adopt awkward positions between clicks. If you do a lot of scrolling, consider a mouse with a “fast scroll” button.

Pay Attention to Details

You can adjust both the speed and the sensitivity of most pointing devices using your computer preferences. If your pointing device seems sluggish, overly touchy, or otherwise troublesome, try experimenting with these settings.

Regular breaks

In addition to regular breaks to stand up and leave your desk entirely, give your hands regular breaks from pointing. If you use a mouse, try alternating which hand you use to operate it. You will of course need a mouse design that supports this. Mice are so cheap now that even a modest budget can support buying an extra mouse if you use a hand-specific model. Likewise, with the huge variety of alternatives pointing devices available you can use different pointing devices for different tasks. Many graphic designers, for example, switch between a graphics tablet and a mouse depending on whether they are sketching out ideas or laying out a design.

Finally, don’t forget about keyboard shortcuts, another great way to take a break from pointing. All operating systems and many individual computer applications let you define keystroke combinations that eliminate the need to use your pointing device for common tasks.

Adapted with permission from “Scared Sitless: The Office Fitness Book.”