PROPER BODY MECHANICS AND YOUR CHAIR
Your chair should be adjustable and stable. Vary your posture in the chair throughout the day. Some people like to switch, during the day, from sitting to standing to promote posture changes.
- Adjust the height of the chair so that your feet are firmly on the floor but not so low that your weight is not evenly distributed over the full seat surface.
- Only use a footrest when attempts to adjust your chair and the rest of the workstation fail to keep your feet on the ground. If you use a foot rest, use a large and solid one.
- Be sure that you have enough space between the top of your thighs and the underside of your workstation.
- Extend your lower legs slightly forward so that the angle between your thighs and lower legs is 90 degrees or more.
- Keep your body in a relaxed yet upright position. The backrest of your chair should support the inward curve of your lower back.
- Use the entire seat and backrest to support your body. Adjust the backrest slightly backwards. The angle formed by your thighs and back should be 90 degrees or more.
- The arm supports should support the forearms comfortably while typing. Adjust the height of the armrests or forearm supports so that when your arms are resting on them your shoulders can relax and be close to your body.
- To prevent having to reach to the front or side, position the keyboard and pointing device (e.g., mouse, trackball, etc.) directly in front and close to you.
- Adjust the keyboard as low as possible without resting it on your legs so that your shoulders are not elevated during keyboard use. To do this, the keyboard and mouse should be on a thin (1 to 2 inches) surface, not on a desk with a drawer underneath.
- If you use a mouse, position it at the same height as the keyboard and right next to it. Grasp the mouse lightly and loosely and keep your wrists straight (fingers curled).
- In general, your elbows are near your body and your forearms approximately parallel to the floor, with your forearms resting on either armrests or forearm supports. The angle created from your shoulders to your elbow and your elbow to your wrist should be 90 degrees. The keyboard and mouse should be on the same plane as your elbows.
- The slope of the keyboard may need to be adjusted so that your wrists are straight, and not bent back (extension) while you are typing.
- Type with your hands and wrists floating above the keyboard (fingers curled). Use a wrist pad only to rest your wrists between typing. Avoid resting your wrist on sharp edges. Your arms should be supported by armrests, thus allowing your shoulders to be relaxed.
- Avoid twisting your wrists sideways to press hard-to-reach keys. Instead, move your whole arm. Keep from bending your wrists, hands, or fingers sideways.
- Press the keys gently; do not bang them. Keep your shoulders, arms, hands, and fingers relaxed.