Apple Macintosh PowerBook 145B - Manual (Page 47)

Arranging your work space and equipment
The suggestions in this section can help you work more
comfortably with your computer.
Chair
Whenever possible, use an adjustable chair that provides firm,
comfortable support.
m Adjust the height of the chair so your thighs are horizontal,
your feet flat on the floor, and the backs of your knees slightly
higher than the seat of your chair.
m The chair should support your lower back. Follow the
manufacturer’s instructions for adjusting the backrest.
Keyboard and trackball
m When you use the keyboard and trackball, your shoulders
should be relaxed. Your upper arm and forearm should
form a right angle, with your wrist and hand in roughly a
straight line.
m Use a soft touch on the keyboard and keep your hands
and fingers relaxed. Avoid rolling your thumbs under
your palms.
m Change hand positions often to avoid fatigue.
This Not this
Not this This
Chapter 1: Setting Up Your Macintosh PowerBook 31