Ergonomic office furniture ... |
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Ergonomic office solutions
Workstation set up - Mouse / Keyboard positioning 1) Position of the keyboard is more important than shape. While “ergonomic” keyboards (i.e. those with curved layouts or split designs) can help keep wrists in safer postures, they can also create other problems, such as shoulder abduction (elbows moving away from the sides of the body). Think of the hand and arm as a chain – what happens at one end effects the other. A safe posture at one end of the chain does not guarantee the same benefit at the other end.
So, keyboard design alone is not necessarily the answer. What is the answer, however, is keyboard position. Liberty Mutual’s Research Institute for Safety reports that input devices themselves may not be the real source of the musculoskeletal discomfort experienced by office workers. "Keyboards are well designed now…, but people do not use the technology appropriately," Tom Leamon, Director of Liberty Mutual’s Research Institute for Safety said in a recent interview with the Boston Globe. "That is why the next innovation must be to have everyone set up their workplaces in a way that will minimize stresses."
To minimize risk for injury, the keyboard should be angled away from the user in what is referred to as a “negative” slope. And it should be placed below desk level, so that the user’s wrists remain straight (“neutral position”) and their elbows open up. The best way to achieve this desired keyboard position is with the use of an articulating keyboard holder with negative tilt adjustability. “Using a lowered keyboard holder on a preset tilt away from the user can help prevent carpal tunnel,” according to the results from a 1995 Cornell study. Such a keyboard position also encourages a healthier seated posture (see diagram). Also, the palm support should only be used as a resting place for the palms between periods of typing. It should never be used as a place to rest the wrists, and never, ever support the wrists during periods of typing. 2) Movement is critical. As with seated postures, being able to change positions frequently and easily is the foundation upon which a good ergonomics program is based. A keyboard platform, such as one used to position the keyboard in a lowered, negative-tilt position, should also allow spontaneous changes to keyboard height and depth, so that the user can easily change positions as different tasks necessitate. It’s also important that such a keyboard platform provide ample knee clearance to maximize lowering capabilities and to minimize the likelihood of BKS (Banged-knee Syndrome). 3) Mouse within the Neutral Reach Zone. With the phenomenal increase in graphics applications and internet use, mousing has become a major cause of CTS. To combat these dangers, it is important to always mouse within the Neutral Reach Zone (see diagram). This follows from Ergonomic Principle #3, in which it’s important to avoid extreme postures. Mousing within the Neutral Reach Zone minimizes shoulder abduction and wrist flexion/extension. 4) Beware the mouse. In addition to position, the mouse itself can also be a major risk factor. Research recently conducted at Cornell University suggests that a mouse with a larger, flatter surface area can reduce wrist extension and therefore CTS risks. The shape of the mouse is also critical. Avoid mice that cause the wrists or fingers to be bent sideways or upward in simply grasping the device. It is essential that users monitor their mousing hand and immediately begin mousing with their other hand at the first sign of any pain or tingling . As a result, it’s important that the mouse be symmetrical so that it can be used equally well in both hands. Likewise, the keyboard platform should allow for mousing on both sides of the keyboard. Creating a Healthy Workstation by Rhonda Crenshaw, Director of Humanscale’s National Ergonomic Group >> Workstation set up continued
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