Workstation Ergonomics

Ergonomics means fitting the workplace to the workers by modifying or redesigning the job, workstation, tool or environment. Workstation design can have a big impact on office workers health and well-being. There are a multitude of discomforts which can result from ergonomically incorrect computer workstation setups. The most common complaints relate to the neck, shoulders, and back. Others concern the arms and hands and occasionally the eyes. For example, poor chairs and/or bad postures can cause lower back strain; or a chair that is too high can cause circulation loss in legs and feet.

Certain common characteristics of VDT jobs have been identified and associated with increased risk of musculoskeletal problems. These include:

• Design of the workstation
• Nature of the task
• Repetitiveness of the job
• Degree of postural constraint
• Work pace
• Work/rest schedules
• Personal attributes of individual workers

The key to comfort is in maintaining the body in a relaxed, neutral position. The ideal work position is to have the arms hanging relaxed from the shoulders. If a keyboard is used, arms should be bent at right angles at the elbow, with the hands held in a straight line with forearms and elbows close to the body. The head should be in lined with the body and slightly forward.

Arranging Your Workstation to Fit You

• Adjust the height of the chair’s seat such that the thighs are horizontal while the feet are flat on the floor.
• Adjust the seat pan depth such that your back is supported by the chair back rest while the back of the knee is comfortable relative to the front of the seat.
• Adjust the back rest vertically so that is supports/fits the curvature of your lower back.
• With the arms at your sides and the elbow joint approximately 90 degrees, adjust the height/position of the chair armrests to support the forearms.
• Adjust the height of the keyboard such that the fingers rest on the keyboard home row when the arm is to the side, elbow at 90 degrees, and the wrist straight.
• Place the mouse, trackball, or special keypads, next to the keyboard tray. Keep the wrist in a neutral position with the arm and hand close to the body.
• Adjust the height of the monitor such that the top of the screen is at eye level. If bifocals/trifocals are used, place the monitor at a height that allows easy viewing without tipping the head back.
• Place reference documents on a document holder close to the screen and at the same distance from the eye.
• A footrest may be necessary if the operator cannot rest his/her feet comfortably on the floor.

Applying Good Work Practices

The way a task is performed and the workstation environment it is performed in, can influence the risk of injury and general work productivity. The following techniques can make a job easy and safe to accomplish.

• Adjusting the drapes or blinds
• Moving the monitor away from sources of glare or direct light.
• Tipping the monitor slightly downward
• Using diffusers on overhead lighting
• Placing an anti-glare filter on the screen
• Clean the monitor screen on a regular basis
• Avoid cradling the telephone between the head and shoulder. Hold the phone with your hand, use the speaker phone, or a headset.
• Keep frequently used items like the telephone, reference materials, and pens/pencils within easy reach.
• Position the monitor directly in front of you.
• Move between different postures regularly.
• Apply task lighting to fit your needs.
• Use the minimum force necessary to strike the keyboard/ten-key keys.
• Use the minimum force necessary to activate the hole punch and stapler.
• Vary your tasks to avoid a long period of one activity.
• Take mini-breaks to rest the eyes and muscles. A break does not have to be a stop of work duties. However, it should be a different style of physical activity such as changing from keyboarding to using the telephone or filing.
• Neutralize distracting noise by using ear plugs, playing soft music, or turning on a fan.
• Maintain a comfortable workplace temperature by using layers of clothing.

Lighting

Lighting is one of the most important factors affecting personal comfort on the job. The best lighting system is one in which the light level is geared to the task, where brightness ratios are controlled (no intensely bright or dark areas in one field of vision) and where ceilings, walls, and floors are carefully chosen to minimize glare. Glare is defined as a harsh, uncomfortable bright light that shines directly in the eyes. Glare may be either direct, coming from lights or sunshine, or indirect, coming from a reflected surface.

Different tasks require different levels of lighting. Areas in which intricate work is performed, for example, require greater illumination than warehouses. Lighting needs vary from time to time and person to person, as well. One approach is to use adjustable task lighting that can provide needed illumination without increasing general lighting.

Vision problems are one of the leading sources of complaints among office workers. Poor office lighting can cause eye strain and irritation, fatigue, double vision, watering and reddening of the eyelids, and a decrease in the power of focus and visual acuity. Headaches as well as neck and back pains may occur as a result of workers straining to see small or detailed items. Poor lighting in the workplace is also associated with an increase in accidents. Direct and reflected glare and shadows as well as delayed eye adaption when moving from bright surroundings into dark ones (or vice versa) may prevent an employee from seeing clearly, resulting in accidents.

There are a number of measures that can be used to prevent and control poor lighting conditions in the work environment:

• Regular maintenance of the lighting system should be carried out to clean or replace old bulbs and faulty lamp circuits.
• A light-colored matte finish on walls, ceilings, and floors to reduce glare is recommended by the Illuminating Engineering Society.
• Whenever possible, office workers should not face windows, unshielded lamps, or other sources of glare.
• Adjustable shades should be used if workers face a window.
• Diffuse light will help reduce shadows. Indirect lighting and task lighting are recommended, especially when work spaces are separated by dividers.
• Task lamps are very effective in supplementing general office lighting for those who require or prefer additional lighting. Some task lamps permit several light levels.