The Five Myths Of Workplace Ergonomics
Myth #1: Your office chair is killing you, really?
Popular press and product sales materials say your office chair is a killer, but let’s be clear about what we know from the research. A large study showed that sitting and low activity increased the risk of obesity, heart disease and diabetes—but that research was done for Leisure Sitting, like at home or in the car (Patel 2010). Medical studies have shown that posture and activity can change how the body manages blood sugar and cholesterol (Owen, Healy). It is important to realize that sitting at work and sitting at home are two very different conditions in terms of physiology. There may be enough activity at work to allow normal blood metabolism. In fact, there was no clear association with an increased risk of those aforementioned diseases when the amount of time spent sitting at work was studied (van Uffelen 2010). Based on the research, sitting at work may be the safest place to sit in terms of disease risk.
Back pain and cumulative trauma through the spine are problems that are clearly associated with seated work, and this course is determined to change that risk.
Back pain from sitting at work may be the combination of several simple causes. Regular slumped seated posture causes a stretch and weakness of the ligaments and the deep postural muscles throughout the spine (Barnett, Twomey). The increased activity of work combined with slumped sitting causes awkward movement at the spinal joints, and it is the poor movement in bad postures that we associate with cumulative trauma injuries, particularly in seated work environments.
Most people describe low back or neck pain as a specific event in the past, but posture is a very quiet partner in the process. Slumping at work and at home is what can prevent a spinal injury from getting better, or cause a gradual onset of low back or neck pain.
The ActivSeating course has been successful to show the user exactly how to solve postural problems at work or at home, and how to adjust the work chair to give support and movement for how the work needs to be done. The key components are two: knowing how to find good spine posture, and then moving the chair and workstation to sustain that posture easily. The results have been remarkable, and in many cases resolving long-standing injuries just by adjusting the existing chair and work surface to fit the body better.
Myth #2: Standing at work is good for you?
The discussion to stand at work should also include the known health risks from standing. Research that specifically looked at the amount of sitting time at work did not find a consistent association for the degree of health risk of diabetes, obesity, heart disease, cancer and death from all causes (van Uffelen 2010). Standing at work can be an expensive solution that does not address the original health risk problem of leisure sitting, and which may not exist at work. Standing workstations may even cause additional health risks (See Pro’s and Cons of Standing).
We do know that briefly standing and walking away from the workstation at regular intervals during the day has a significant effect on reported symptoms at the upper and lower back, and a ten percent (not significant) improvement in productivity (Davis). This result was completely independent of the workstation design, since sitting and sit-stand workstations had the same result.
A study on heart disease measured the amount of effort when men went from sitting to standing a little, a lot or all the time (Krause 2007). Those men were also measured for their risk of increasing thickness in the arteries of the heart. If heart disease was already present, moving from sitting to standing work increased the risk of heart disease from three to nine times!
A study done in 2005 showed an almost two-fold increase in the risk of hospitalization for varicose veins when people stand and walk more than half the day (Tuchsen).
A recent large-scale Canadian study showed half the risk of a cardiac event for seated jobs compared to work that was done standing or walking (Smith 2018).
Studies show that people really don’t want to stand at work. A study of office workers who had sit-stand desks for more than a year found that sixty percent adjusted the table to stand less than once a month (Wilks 2006), people with a sit/stand option only sat 5% less than at those at conventional sitting desks (Straker 2013), and when provided a sit-stand option, people need to be told to stand (Robertson 2013). One study estimated that about 10-20 percent of the population may prefer to stand, but that may not be the population at risk, and it certainly does not change the problems for those who remain sitting (Straker 2012).
Myth #3: More activity at work is good for you?
If every kind of sitting is considered the cause of disease risk, it seems reasonable that standing, and generally more activity at work should be better. Unfortunately, simply increasing the effort at work may have unintended consequences that may be far worse, particularly with the known disease risks reported with increased work demands (Smith, Krause 2007).
To find a working solution, we need to mitigate precisely how those risks affect the body. The studies show that passive inactivity in the chair that causes damage to our metabolism and decreases mental acuity. Slumping causes the muscles holding our posture upright to relax and shut off (Burnett 2009, Callaghan). This relaxation stops the activity of the enzyme that controls normal blood and fat metabolism, and increases the physiologic risk of diabetes, obesity and heart disease (Bey, Owen). Activity of the postural muscles seems to normalize blood sugar and fat metabolism (Healy), and that modest activity may be the reason sitting at work does not present a clear risk of those diseases.
The ActivSeating process is designed to allow the postural muscles to work easily and often, and provides frequent rest opportunity without losing neutral spine position, and there has been tremendous improvement reported for the frequency and severity of discomfort, specifically low back pain and neck, shoulder, arm and hand pain which is the musculoskeletal component. We have not measured the changes in blood hormone levels, but we can expect that sitting with more active postural muscles will have additional benefits.
Myth #4: A good chair will solve the problem?
Often the “best” ergonomic chair is designed for only one kind of work—that which is relined and relaxed. The unspoken expectation is that the user can adapt their work to be done in that relaxed posture. If the work demands draw the torso forward the result is slumped posture, unless the chair can be adjusted to support the new forward posture. The combination of a reclined chair and forward work tasks is the most typical cause of slumped posture. Initially, slumping doesn’t seem to be a problem, but over time the damage is clear. Often, the user does not know how or when to adjust the chair, or maybe the chair cannot be properly adjusted.
When user can easily test their best posture, it is a clear matter to make adjustments to support that posture. Sustaining that best posture during the work routine requires more than simple chair adjustment.
Getting the chair to meet the demands of forward work may not be well tolerated unless the body can work in a balanced posture. Postural sustainability requires the muscles of the legs to actively support the body upright along with passive support from the chair. The final piece of the puzzle is to position the work surface support to meet the body’s stature and allow an easy place to rest the arms with free movement.
A proper chair with the fit and features that meets the work demands is important, but the user still needs to know how and when to make adjustments, and the work surface needs to fit the stature to properly support the body at the job. The problem is solved when all three elements are in place.
Myth #5: Computer work needs an adjustable keyboard tray?
OSHA Ergonomic Guidelines suggest that an adjustable keyboard tray is recommended for computer use more than four hours daily, but how the computer work is done may predict when to use an alternative method. Early computer work was primarily data-entry, and it was done by skilled keyboard users. That kind of production keyboard use required full freedom of the arm and hand to sustain the high speed and volume of keyboard entry for transcription or dictation.
When computer work requires intermittent or sustained visual cues to the keyboard, either by a non-skilled keyboard user, or there are frequent interruptions to steady keyboard use, like use of the mouse or phone, a number of studies show that a stable forearm support can significantly reduce symptoms at the arm and hand (Conlon, Cook, Gerr, Rempel 2006).
Many adjustable-height standing workstations use a keyboard tray that is fixed at level, and does not allow forearm support. The end result is that there is greater neck bending to look at the keyboard, and the weight of the arm is resting at the carpal tunnel.
The ActivSeating™ process is very specific to locate the full depth of the work surface support at precisely the right height to allow normal shoulder movement, after the torso and leg postures are determined. In this position the weight of the arm is carried through the length of the muscles in the forearm at rest, yet the forearm can still float for keyboard use. Additionally, neck bend is greatly reduced to look at the keys. Although the process was intended for the reduction of low back pain, the nice surprise is that there is less discomfort reported at the neck, shoulder and arm, even more than the low back. Importantly, no one was worse.