Ergonomics in the workplace

Business Operations -- Ergonomics Issues Summary

Repetitive Motion Problems

Prior to the widespread use of computers in the workplace, ergonomics issues in the workplace most often involved repetitive motion injuries. Generally, repetitive motion injuries develop gradually; they are caused by the constant repetition of physical tasks performed hundreds or even thousands of times in a work shift. Moreover, certain physical tasks require unnatural positions or otherwise anatomically stressful motions. Another closely related source of ergonomic strain is that caused by chronic exposure to excessive vibration, such as that associated with operating heavy-duty power tools and construction equipment.

Virtually any motion, even those that are not necessarily unnatural or difficult, can present serious ergonomics issues when they are repeated excessively. While it may be difficult to avoid repetitive motion-related injuries in performing certain tasks, stretching the areas involved prior to work shift can help reduce their development; frequent breaks also help minimize strain of this nature.

Computer Monitor Issues

Computer monitors present several different potential ergonomics issues. First, long-term uninterrupted viewing of a bright LED computer monitor can result in eye strain. To avoid eye-strain computer users should take a short break after approximately an hour of computer use. Ideally, looking out toward the horizon through a window allows the eyes to relax and recover. Second, computer monitors can be the source of significant neck pain as well. Looking either upward or downward at a computer screen for prolonged periods can cause chronic neck and shoulder problems. These can be some of the most serious physiological consequences of the failure to consider ergonomics in workstation setup because neck strain can also trigger headaches and also interfere with sleep. To avoid neck strain, computer users should make sure that the top edge of their computer monitor is approximately eye level so that they can view a 60-degree range from the screen to their keyboards without prolonged excessive neck tilt in either direction.

Keyboard and Mouse Issues

The keyboard can trigger several different ergonomics issues as well. First, the keyboard should be set on an adjustable tray that enables the user to maintain a 90-degree angle at the elbow when the elbow is supported by armrests. Without armrests, maintaining the proper angle becomes difficult because the muscles of the shoulders become fatigued leading to chronic strain.

Second, failure to maintain a 90-degree angle at the elbow will trigger wrist strain associated with carpal tunnel syndrome because it necessitates an unnatural downward bend that stretches tendons in the area. Conversely, arm rests that are too high compress the wrist tendons because they cause a prolonged upward bend to allow the hands to reach the keyboard. Generally, carpal tunnel syndrome results from either prolonged stretching or compression of the wrist tendons within the fibrous sheath surrounding them. The other keyboard issue is that some computer users have a tendency to turn their hands outward in the horizontal plane. This also triggers chronic carpal tunnel problems.

To avoid keyboard-related wrist problems, keyboard trays must allow a neutral wrist position in both the vertical and horizontal planes. Sometimes, this requires the use of a split keyboard that allows ergonomic wrist positioning for users who have difficulty reaching keyboard keys without excessive outward bending of the wrists.

The computer mouse can also cause ergonomic-related problems when computer users must reach for them or alter the ergonomically correct arm positioning to reach the computer mouse. Even a properly positioned keyboard tray will not solve arm and shoulder problems when computer users position the mouse on the desk. To avoid having to reach for the mouse, the keyboard tray should also have a mouse support that allows the user to use it without changing the ergonomically correct arms position. Ideally, the mouse support should be separately adjustable from the keyboard tray to maximize adaptability to each user's unique requirements.