Oh, how we love technology. When you think of how much time many of us spend sitting in front of a computer screen, you might conclude that most companies put considerable effort into designing individual workstations to maximize safety, comfort, and productivity.
Alas, you would be wrong. The way in which a user works with computer systems such as a CMMS often affects realization of the system’s benefits. That’s why we need to consider ergonomics – i.e., the adaptation of mechanical equipment to human characteristics – as it pertains to computer workstations.
Ergonomics is an area often overlooked when purchasing, upgrading, or reconfiguring a CMMS. This may surprise you, given the extensive history of health and safety issues experienced by companies that have chosen to ignore the interface between people and the work environment. For example, for many CMMS implementations, basic decisions such as where to put the computer equipment and the optimum design of a workstation are last-minute realities.
Numerous studies point to the benefits of a well-designed work environment. Employers can pay dearly each year for stress- and strain-related lost-time injuries. These injuries are invariably traced back to ignorance or to simply ignoring simple ergonomic design considerations such as outlined below.
Distance from video display: The video display should be no more than 24" and no less than 15" from your eyes. Any closer and you increase the risk of radiation exposure from some screens. In addition, lower-definition displays will have a more grainy appearance. At a distance of greater than 2 feet, the display will be more difficult to read. In either case, the possibility of eye strain increases dramatically.
Video display height: A line drawn from the center of the screen to the tip of the nose should be 10 to 20 degrees below the horizontal. People who have multiple lenses such as bifocals require a minimum of 20 degrees or special lenses. Adhering to these angles minimizes possible neck strain with prolonged use.
Screen brightness: Adjust the brightness on video displays to as low a setting as is comfortable. Eye strain and headaches can result from settings that are too bright.
Placement of documents: Any source documents used in keying should be suspended in the same plane and at the same height as the video display, at the same distance from the operator. This requires use of an adjustable stand. Neck and eye strain occurs when, for long periods of time, users view documents on the table beside the video display.
Ambient lighting: Avoid any natural or office lighting that may cause a glare, such as from a light source placed in front of the video screen.
Keyboard height: Avoid bending the wrists while typing. Various wrist support devices can be purchased to maintain a straight line parallel to the floor from knuckles to elbows. Your elbows should hang comfortably by your side.
Carpal tunnel syndrome is caused by performing repetitive tasks with your wrists in awkward positions. It can be extremely painful and debilitating as tendons swell and put pressure on surrounding nerves. People with carpal tunnel syndrome initially experience a numbness, tingling, or burning sensation. If left untreated, permanent damage may occur, making it impossible to return to the same type of work.
Key spacing: The spaces between keys on a keyboard or keypad should accommodate a variety of finger and hand sizes. Many handheld devices have inadequate spacing for people with large fingers. This increases the data-entry error rate and makes it extremely frustrating for operators.
When spacing is too great or when accessing special keys requires excessive reaching by the fingers, then hand and finger strain can occur in the form of tendinitis. Tendinitis is caused by the irritation and swelling of the tendons, the tissue connecting bones to muscles.
Key shape: The top face of the keys should be concave to help fingers locate the center of the key. Sometimes keys are marked tactically using a protrusion on the key. Typically, the “F” and “J” keys on a QWERTY keyboard and the “five” key on a numeric keypad are marked in this manner. These protrusions make it easier for fingers to move to the proper starting position without looking down at the keyboard.
Key movement: When you depress a key, there should be enough movement so as to give a tactile sensation affirming successful completion of the keystroke. Sometimes this is accompanied by a clicking or beeping sound for further verification, as is common with touchscreen keypads on smartphones. Without some level of confirmation while keystroking, it is difficult to achieve high levels of productivity and accuracy.
Workspace dimensions: The work space height, length, and width should minimize the need for bending, twisting, or stretching. This reduces strain on all muscles and joints, especially in the back. In recent years, adjustable work surfaces have become more popular as they allow users to alternate between sitting and standing positions throughout the day for improved health and productivity. For safety, security, and privacy, work spaces should be physically separated from one another.
Body support: The chair should support the natural curves of the body, as with lumbar support for the curved spine. The seat should support the thighs but not hit the back of the knees. Feet should be flat on the floor at a 90-degree angle. An angled foot rest adds greatly to comfort. Make sure knees and legs are not cramped under the work surface.
Chair arms should support forearms parallel to the floor without requiring a person to lift shoulders or stretch forward to reach the keyboard. The chair arms should be low and short enough to let the legs slide under the keyboard.
Chair stability: To avoid tipping, the chair should have five legs. Castors should be hardy enough to roll easily over rough surfaces in any direction.
Adjustment capability: Change your position and chair settings throughout the day to reduce fatigue. Adjustments should be accessible while seated wherever possible.