RSI: What you absolutely need to know
Use of a computer keyboard and/or mouse can lead to persistent muscle aches, tendon inflammation, nerve compressions, and subsequent impairments that in some cases may be long standing. The MIT Medical Department sees nearly 300 people a year for problems such as these caused by overuse and/or misuse of computer workstations. The musculoskeletal system is built to have periods of activity alternating with periods of rest that allow recovery and renewal. Working at a computer long hours subjects certain parts of the body to static postures while other parts move incessantly. Both static postures and constant activity can cause first microscopic and then macroscopic damage to biologic tissues.
There are four keys to RSI Prevention: Position, Pacing, Technique, and Exercise.
Adjust yourself and your workstation to minimize the awkwardness and stress involved in keyboard activity.
- Use a telephone headset instead of cradling the phone between ear and shoulder.
- Rest feet on the floor or on a footrest, support thigh by soft chair, support lower back.
- Let upper arms hang loosely from the shoulder, extend forearms horizontally toward the keyboard, lower and angle keyboard slightly away (negative pitch) so the wrists are in a neutral position, with mouse next to the keyboard at the same level. Do not lean wrists on any surface (including wrist rest) while typing or mousing.
- Center yourself in front of a glare-free monitor; keep eyes at a comfortable distance from the monitor, looking down at a 10-30 degree angle.
Introduce breaks in your typing to permit recovery and restoration, and do this at a frequency that does not allow pain or discomfort to develop. No schedule of typing and rest breaks is universal, but as a general guideline:
- Take a 1 or 2 minute "micro break" every 10 to 15 minutes;
- Take a 5 to 10 minute "mini break" every hour.
- Every few hours, get up and do some alternative activity.
Using a timer or other automatic reminder is helpful to make sure that you take breaks at these intervals rather than waiting for fatigue or discomfort. During breaks, do stretches to relax muscles. Consider using typing break software. Stretch Break Pro is a typing break program for Macintosh and Windows that reminds you to take periodic breaks from your computer and provides stretches and ergonomic information. It is available to the MIT community free of charge.
Use a typing technique that does not traumatize the fingers and wrists but rather involves movement of the arm as a whole. Typing technique should emphasize fluid movement of the arms to avoid angling the wrists forward, back, or side-to-side. Press the keys lightly. When not actively typing, rest hands, thumbs up in your lap ("neutral posture") rather than resting them on a pad or the keyboard edge. When a command requires key combinations, use two hands to avoid contorting the hand. Use software programs allowing "sticky keys" and macros whenever possible. An alternative keyboard and/or pointing device may benefit some individuals.
General aerobic exercise, done regularly, will sustain strength, improve cardio-vascular conditioning, and quicken recovery from sedentary computer use. Also learn to do a series of stretches during rest breaks that restore health and vitality to your body. As a general rule, none of these should involve movement outside the range of motion and nothing should be done that hurts. The purpose of stretching is to relax muscles and improve circulation. Arm strengthening should not be emphasized.