Approximately 45 percent of people between the ages of 25 and 64 used a computer at work in 2010, reported the U.S. Census Bureau. Typing on a computer keyboard is probably the most common cause of carpal tunnel syndrome, a painful and potentially disabling condition. The following tips can help you prevent carpal tunnel syndrome.
Many computer tasks are highly repetitive. Computer users may perform the same motions repeatedly at a fast pace and with little variation. A computer user may remain in essentially the same posture for an entire shift. Combining repetitive tasks with factors such as awkward postures and excessive force may increase the risk of injury.
Proper posture may help reduce the risk of developing carpal tunnel syndrome:
- Shoulders and upper arms should be in line with the torso, generally about perpendicular to the floor and relaxed (not elevated or stretched forward).
- Upper arms and elbows should be close to the body (not extended outward). If not, the employee’s workstation might need adjustment.
- Forearms, wrists and hands should be straight and in line (forearm at about 90 degrees to the upper arm) to allow the tendons to slide easily without interference.
- Wrists and hands should be straight (not bent up/down or sideways toward the little finger).
Preventive Measures
Adjustable workstations can help workers maintain proper posture and may help prevent carpal tunnel syndrome and other musculoskeletal disorders. At a minimum, a worker who uses a computer regularly should be able to adjust his/her:
- Chair: Users should be able to sit with their feet firmly on the floor, with thighs approximately parallel to the floor or hips slightly higher than knees, with legs approximately perpendicular to the floor. If the chair is not fully adjustable, a foot rest can help.
- Monitor: Monitors should be positioned so the employee’s head and neck remain vertical and in-line with the spine, not bent or twisted. Adjustable-height desks or monitor stands can elevate a computer monitor as necessary. To prevent the worker from needing to tip his/her head backward to see the screen, the top of the monitor should not be above the worker’s horizontal line of sight.
- Work surface: A computer keyboard should be on a sturdy work surface that allows a worker to maintain a level forearm posture whenever possible, without rotating the forearm repeatedly, especially when the wrist is bent.
Do “alternative” keyboards help? NIOSH, the National Institute for Occupational Safety and Health, reports that alternative keyboards can promote the preferred, neutral wrist posture. “Yet available research does not provide conclusive evidence that alternative keyboards reduce the risk of discomfort or injury.” However, employees who do a lot of typing might find an alternative keyboard more comfortable to use, so they are worth trying.
Alternative keyboard designs include:
- Split keyboards. This can be done in two ways: by increasing the distance between the right and left sides of the keyboard or by rotating each half of the keyboard so that each half is aligned with the forearm. This design helps keep the wrists in neutral position.
- Tented keyboards. On tented keyboards, the two keyboard halves are tilted up like a tent. This feature reduces the rotation of the forearms.
- Built-in wrist or palm rests. Built-in wrist or palm rests help prevent bending the hands up by providing support that straightens the wrists.
- Adjustable negative slope. This design allows the user to raise the front edge of the keyboard, or to slope the keyboard backward, thus straightening the wrist.
- Key position. Some alternative keyboard designs have curved rows of keys or keys placed in concave wells to accommodate the different lengths of a user’s fingers.
When evaluating alternative keyboards, make sure the keys are visible. This is particularly important for “hunt and peck” typists. Also, check whether the job requires use of the numeric keypad and specialized keys, because some alternative keyboards eliminate or reconfigure these keys.
If you’re one of the many people, like the one writing this, that sits at a keyboard most of the day, make time to get up and walk around, do some stretching, jog in place, or take a stroll around the block at lunch. Your employer would much rather you spend an extra five minutes a day doing laps around the office than paying for workers’ comp for carpal tunnel surgery!
If this post got you wondering about ergonomics in the workplace, give us a call, and we can get you started in the right direction.