Computers are a vital part of the modern office environment. They only require a very small range of movement but allow us to work faster and more efficiently. However, the human body is not designed for sitting at a computer workstation for long periods of time. This means that physical and psychosocial injuries are more likely to occur.
The most common injuries that occur in the modern office environment happen gradually rather than suddenly. Common physical injuries include musculoskeletal disorders (MSD), which is a collective term for a range of conditions characterized by discomfort or pain in muscles, tendons and other soft tissues, with or without visible symptoms. MSDs are usually associated with tasks involving repetitive movement, sustained or unnatural postures or forceful movements. These conditions have been referred to by various names, including Occupational Overuse Syndrome (OOS) or Repetitive Strain Injuries (RSI).
Muscle strains can occur suddenly, resulting from forceful exertion in a bent or twisted posture, but many occur due to daily work that involves staying in one posture for long periods of time, which results in muscle fatigue. Examples of such daily work includes holding a telephone for multiple or long calls, and repetitive work such as keyboard and mouse tasks.
The time spent in a posture is crucial in determining the need for correction. There are two general approaches to the problem:
Avoid prolonged maintenance of constrained postures by ensuring frequent rest breaks, designing the job to provide variety, and limiting the proportion of the working day which has to be spent on some activity which constrains posture (e.g. continuous keying); and
Minimize the need for poor posture in all activities by giving attention to furniture and equipment and its proper arrangement and adjustment.
People come in all shapes and sizes and have a wide range of different needs, capacities and limitations. Good job and work environment design relies on matching the work and environment to the individual’s needs capacities and limitations:
Repetitive tasks (e.g. using a keyboard and mouse) should be performed for short periods. They are best interspersed with other tasks requiring different postures and movements (e.g. collecting work at the printer, reviewing, photocopying and distributing documents);
Static or fixed postures should only be held for short periods of time and interspersed with different tasks; and
Job design should provide the opportunity for people to sit, stand or walk a short distance as a normal part of their duties.
The important aspect of physical job design is that it fits with how our bodies operate. Points to consider include:
Joints should be in relaxed and comfortable positions. This makes the work of muscles, ligaments and tendons around the joints more efficient. Where extreme positions must be used, they should be held for as little time as possible and should not be repeated often;
The work should be kept as close as possible to the body to minimize the stress on the body when reaching to perform a task;
Commonly accessed items should be stored between hip and shoulder height where possible to avoid bending over and reaching up;
Exertion from the use of excessive force should be avoided; and
Exertion of force should be done in an upright posture, without twisting the spine and preferably using both hands equally.