Ergonomics is the science of adapting work processes and conditions to fit the physical capabilities of workers in order to reduce musculoskeletal injuries (MSI). MSI are injuries of the soft tissues, muscles, joints, tendons, ligaments and cartilage and may also involve the nervous system. The most common examples include repetitive strain injuries such as tendonitis and carpal tunnel syndrome as well as back injuries involving muscles, ligaments and/or spinal discs.
Workplace injuries due to the postural and repetitive strain caused by long term computer use are among the fastest growing injuries in North America. One of the greatest difficulties of these types of injuries is their insidious nature. They develop slowly over weeks, months, and years. Often the worker may not feel that they are at risk for injury as they view their job as relatively sedentary.
One of the best ways to deal with these injuries is to avoid them in the first place. The best way to do this is to minimize the possible instigating factors by designing and modifying workstations to avoid the common contributing factors to these injuries.
Here are a few helpful suggestions:
Workstation chairs are probably the most recognized ergonomic issue. Generally, a good chair includes multiple adjustable parts including; a height adjustment, a backrest adjustment and a seat pan tilt adjustment. Other important features include a good lumbar support to support the natural curvature of the lower back, a rounded front edge to the seat pan to avoid pressure on the back of the thighs and a five point wheeled base for stability.
Armrests that have a height adjustment are advisable so that the elbows are supported to avoid shoulder and neck strain. Further, armrests that swing in and out so that they cross in front of the body increase the adaptability of this feature. Finally, the armrest pads should be soft, preferably made from a soft foam or memory gel to avoid contact fatigue.
When adjusting seat height, the chair should be adjusted so that the forearms rest horizontally at approximately 90 degrees with the hands resting comfortably just above the lap with approximately 8 to 15 cm of space between the top of the lap and the keyboard.
Monitor Distance and Viewing Angle
Generally, monitors should be placed a minimum of 25 inches away from the eye. When the monitor is too close it will cause greater eyestrain. The distance may be greater and will be based on the comfort of the worker. No complications have been associated with distances greater than 25 inches.
The monitor height should be adjusted so that the first line of text is approximately level with the eyes in horizontal gaze when in the correct seated posture. It is recommended that the monitor be located between 15 degrees and 50 degrees below the horizontal gaze.
Footrests can help with the common problem of the relationship between desktop height and keyboard height. Problems here often put undue strain on the lower back. Footrests also decrease the amount of pressure on the back of the thighs and allow for more flexibility in postural positions.
This is but a small sample of suggestions regarding this topic. It is best to consult a professional that specializes in designing and setting up work stations to minimize the risk of developing injury.