Ergonomics

Care for Your Back, Feet and Neck

As many as 80% of the population complain of some kind of back pain in their lifetime. Long periods in front of a computer without proper lower back support can aggravate or heighten back pain.  Improper keyboard and table height can be associated with shoulder, arm and neck pain.

Additionally if work is not placed in comfortable viewing range with something like a copy holder, one can experience shoulder, arm and neck pain. One study points out that with all of the focus on the lumbar region of the back, the backward sloping chair has emerged in an attempt to support the lumbar region of the back. The backward slope can put pressure on the knees. In a 1986 study, subjects with back pain found relief by raising table and chairs by 7 cm.

Your chair should have armrests and when you are seated, your feet should be flat on the floor. Your desk or table should be about two inches lower than your elbow.  If your chair is not ergonomically designed, with adjustable arm rests, height control, and lumbar support, an add-on lumbar roll is a simple, inexpensive correction to the problem. The roll does two things: it helps both the outward curve of the spine in the thorax and the inward curve of the spine in the lumbar—-the more natural weight-supporting body position. Feet that are crossed do not help to support the body.

Your back, in turn, bears all of the weight incorrectly which can lead to discomfort after even a short period of time. When your wrists are straight and your fingers are resting on the keyboard, your weight will be correctly distributed.

In addition, improper keyboard and table height can be associated with shoulder, arm and neck pain. If your work is not placed in a comfortable viewing range with something like a copyholder, one can experience shoulder, arm and neck pain.

According to a recent study, no one posture is best for all video display terminal (VDT) work. People need to lean forward for copy work and back for VDT work. An ergonomically designed chair can support the body in the multiple positions required. A chair’s seat should adjust forward and back, the backrest angle should be adjustable, the backrest height should be adjustable and the seat height should be adjustable.Workstation Design Checklist  Following is a simplified checklist for workstation design. This quick checklist, if satisfied before every work session, will ensure that a workstation is set up as efficiently and ergonomically soundly as possible.

The information provided is the consensus of many ergonomics sources. Studies have shown, though, that an individual’s preferred settings can deviate from usual recommendations. What is important is finding settings that are comfortable for you. Single distances or angles are not given; rather, ranges are, since finding what works for you is most important.

• Monitor 18-24” from eyes.
• Top of monitor no higher than 0 degrees.
• Center of monitor at 15 degrees.
• Bottom of monitor no lower than 40 degrees.
• Elbow parallel to middle of keyboard.
• Lumbar region of the spine: inward curve.
• Thorax: outward curve.
• Eyes parallel with top of monitor.
• Forearm parallel to floor.
• Wrist straight.
• Chair swivels so operators can move periodically.

Computers and Your Vision 

According to the World Health Organization, while it appears that VDT’s do not lead to permanent damage to the eyes, visual discomfort is so widespread among operators that it must be regarded as a health problem and should be addressed.

Eyestrain, visual impairment and visual fatigue can come from a variety of sources including lighting conditions, glare, dirty screens, improper screen contrast and improper screen placement. In an earlier study from the World Health Organization, task lighting, general lighting and screen lighting were all tested for impact on the visual comfort of computer users. The study found that the design of light sources in an office environment could greatly aid or hinder visual comfort.

The choice of background and character color can greatly influence eye comfort or discomfort. Choosing colors which do not have a high level of contrast can lead to blurry vision, burning eyes, dry eyes, and even neck, back and shoulder discomfort. Visual impairment (fatigue or irritation) can persist during off-work hours and, in cases of extremely heavy VDT use such as data entry can last until the next morning. It is generally understood, however, that VDT-associated eyestrain is only temporary.

What’s to be done? The first is proper workstation design with respect to characteristics such as screen height, desk and screen placement, and glare management. The next is a proper eye care regime. This includes eye rest, exercise, and medical examination.