Apple Studio Display (17-inch, CRT) - Manual (Page 28)

28 Chapter 3
Another type of musculoskeletal concern is repetitive stress injuries (RSIs), also known as
cumulative trauma disorders (CTDs). These problems can occur when a certain muscle or
tendon is repeatedly overused and forced into an unnatural position. The exact causes of
RSIs are not totally understood, but in addition to awkward posture, such factors as the
amount of repetition, the force used in the activity, the individual’s physiology, workplace
stress level, and lifestyle may affect the likelihood of experiencing an RSI.
RSIs did not suddenly arise when computers were invented; tennis elbow and writer’s cramp,
for example, are two RSIs that have been with us for a long time. Although less common than
other RSIs, one serious RSI discussed more often today is a wrist problem called carpal
tunnel syndrome, which may be aggravated by improper use of computer keyboards. This
nerve disorder results from excessive pressure on the median nerve as it passes through the
wrist to the hand.
This section offers advice on setting up your work area to enhance your comfort while you
use your computer. Since the effects of repetitive movements associated with using a
computer can be compounded by those of other work and leisure activities to produce or
aggravate physical problems, proper use of your computer system must be considered as just
one element of a healthy lifestyle.
No one, of course, can guarantee that you won’t have problems even when you follow the
most expert advice on using computer equipment. You should always check with a qualified
health specialist if muscle, joint, or eye problems occur.
Eye Fatigue
Eye fatigue can occur whenever the eyes are focused on a nearby object for a long time. This
problem occurs because the eye muscles must work harder to view an object that’s closer
than about 20 feet (6 meters). Improper lighting can hasten the development of eye fatigue.
Although eye fatigue is annoying, there’s no evidence that it leads to permanent damage.
Whenever you’re engaged in an activity that involves close-up work— such as reading a
magazine, doing craft work, or using a computer—be sure to have sufficient glare-free
lighting and give your eyes frequent rest breaks by looking up and focusing on distant
objects. Remember to have your eyes examined regularly.
To prevent discomfort and eye fatigue:
m Arrange your work space so that the furniture is properly adjusted for you and doesn’t
contribute to an awkward working posture.
m Take frequent short breaks to give your muscles and eyes a chance to rest.
Avoiding Fatigue
m Change your seated position, stand up, or stretch whenever you start to feel tired.
Frequent short breaks are helpful in reducing fatigue.
m Use a light touch when typing or using a mouse and keep your hands and fingers relaxed.