In information technology, cumulative trauma disorder (CTD) refers to any of several physical problems that can result from improper or excessive use of a computer display or terminal. Other terms for repetitive stress disorders are repetitive stress injury (RSI) and repetitive motion disorder (RMD) .
Perhaps the most well-known CTD is carpal tunnel syndrome . In occupations involving long hours of keyboard use over a period of years, the tissue in the wrist can become chronically inflamed and swollen. In severe cases, scarring occurs. The main nerve leading from the arm into the hand becomes pinched. The result is arthritis-like pain and stiffness in the hand and fingers. If not treated, the condition can progress until keyboard use becomes impossible. Proper hand positioning, and the use of wrist supports, can minimize the risk that a computer user will develop this syndrome.
Poor posture, caused by improper chair height, a desk that is too high or low, or a display too far below eye level, can bring about back pain and spasms. In severe cases, the condition can be disabling, and its cause can be mistaken for an organic illness such as kidney disease. Pain and stiffness may also occur in the legs, neck, and shoulders. The problem can usually be corrected by paying careful attention to ergonomic aspects of the computer or workstation.
Any type of close-range work over a period of years can cause nearsightedness. Poor lighting, improper display adjustment, or the use of excessively small fonts and/or graphics can result in eye strain, often attended by chronic headaches that can be mistaken for migraines.