Apple EMac Handbuch

    Care, Use, and Safety Information

 

Ergonomics

When you use the keyboard, your shoulders should be relaxed. Your upper arm and 
forearm should form an angle that is slightly greater than a right angle, with your wrist 
and hand in roughly a straight line.

Use a light touch when typing and keep your hands and fingers relaxed. Avoid rolling 
your thumbs under your palms.

Change hand positions often to avoid fatigue. Some computer users may develop 
discomfort in their hands, wrists, or arms after intensive work without breaks. If you 
begin to develop chronic pain or discomfort in your hands, wrists, or arms, consult a 
qualified health specialist.

An adjustable chair that provides firm, comfortable support is best. Adjust the height of 
the chair so your thighs are horizontal and your feet flat on the floor. The back of the 
chair should support your lower back (lumbar region). Follow the manufacturer’s 
instructions for adjusting the backrest to fit your body properly.

You may have to raise your chair so your forearms and hands are at the proper angle to 
the keyboard. If this makes it impossible to rest your feet flat on the floor, you can use a 
footrest with adjustable height and tilt to make up for any gap between the floor and 
your feet. Or you may lower the desktop to eliminate the need for a footrest. Another 
option is to use a desk with a keyboard tray that’s lower than the regular work surface.

Position the mouse at the same height as your keyboard and within a comfortable 
reach.

Arrange the computer so the top of the screen is slightly below your eye level when 
you’re sitting at the keyboard. The best distance from your eyes to the screen is up to 
you, although most people seem to prefer 18 to 28 inches (45 to 70 cm).

Position the computer to minimize glare and reflections on the screen from overhead 
lights and windows.

Go to www.apple.com/about/ergonomics.

LL2385.book  Page 60  Thursday, September 4, 2003  5:20 PM