Advances in technology over the past 20 years have led to changes in the way we work in an office environment. As we use computer keyboards and mouses more and more, we are finding an increase in the instances of cumulative trauma disorders (CTDs). CTDs are defined as wear and tear on muscles, tendons, and sensitive nerve tissue caused by continuous use. Examples of CTD in the upper extremity are carpal tunnel syndrome, tendonitis, DeQuervain’s syndrome, and trigger finger. The commonly cited risk factors for these include repetitive hand, arm and shoulder motions, sustained and/or forceful exertions, and awkward postures. A repetitive job is one in which a task is performed over and over again. The more often you repeat the same movement during the day the greater the chance of developing CTD. Two good examples of repetitious work in an office environment are keying and sorting. Both of these job activities are completed with the same movement and hand position many times during the work day. Sustained actions are seen in the upper extremities during data entry where the arm is held over the keyboard for an extended period of time. Holding a pen in a pinch grip or using a keyboard that does not have soft touch keys can place excess demands on the hand and wrist. Awkward position and posture include body positions such as: bent wrists, elbows away from the body, outstretched arms or excessive reaching, slumped shoulders, twisting and bending.
Ergonomics has been defined as the study of how the workplace relates to human functions and limitations. Making simple adjustments on how you do your work and the way you set up your workstation will allow you to be more comfortable and productive. The idea is to adjust your workstation to your body rather than to adjust your body to the work station. The key to good body movement is working in neutral, which in simple terms means, keeping your body in its natural alignment. The ideal chair for your work station should adjust in height easily so that your thighs are nearly parallel with the floor and your feet are flat on the floor or on a foot rest. The height of the keyboard is dependent on the height of the desk and of the chair. Ideally the arms should rest at your sides with the elbows comfortably bent to about 90 degrees. If the keyboard is too low, put pads of paper under it. If the keyboard is too high, place a padded support under the wrists to elevate them. When possible, work with your wrists in a straight, relaxed position. Excessive or repetitive bending of the wrists cause strain and pressure on the joints, tendons, blood vessels, and nerves passing through the carpal tunnel. The fingers should be in a position on the keyboard so that the keys are easy to reach. Persons with long hands and fingers need to adjust the keyboard so it is more flat and those with short hands and fingers need to adjust the keyboard so it is on more of an incline. It is important to decrease the number of long reaches you make during the day. The most commonly used items should be located closest to you and limited to the range between the waist and shoulder heights. The top of the display screen of your monitor should be at or just below eye level. Keeping the head over the shoulders reduces the strain on the neck and improves blood flow to the upper body. Using a shoulder rest on the telephone or headsets are a good alternative for individuals who must use the phone frequently or for long periods.
Working efficiently does not always mean working fast. Microbreaks from writing, keyboarding and lab work every 30 minutes are essential. Stretching exercises a few times an hour are much more effective than a 15- minute break every 2 hours. Be aware that non-work factors that increase CTD risk are poor physical condition, smoking, poor nutrition, personal stresses, previous injuries, again, hobbies, and certain diseases that can reduce the body’s tolerance to stress. Although there are no standards for what constitutes excessively repetitive or forceful work, common sense dictates that such factors should be minimized to the extent possible, especially in situations in which upper extremity musculoskeletal disorders have been reported.