Laboratory Ergonomics - Part 1
You go home each day with a pain in your shoulder or neck, and perhaps you wake up at night with tingling sensations in your wrist or hand. What to do? You have grant or budget information to enter in spreadsheets; you have a stack of standard operating procedure, chemical hygiene plan, or chemical inventory documents to review and update; and it seems you get three e-mails for every one you send. No matter how you look at it, this means hours and hours glued to your keyboard and mouse. Read on to learn about office ergonomics and what you can do to minimize the potential ill effects of all this computer usage.
Simply put, ergonomics is the study of how people physically interact with their work environment to perform their required tasks. Ergonomic conditions can affect those working in all types of laboratories. The “office” aspect of laboratory research should not be overlooked, and that will be our focus in this issue and the next. More and more, jobs require a substantial portion of the day working with a computer. Very often, the pain and discomfort experienced at work or at home can be tied to ergonomic risk factors. Poor ergonomic conditions and practices result in more losses due to employee suffering, lost time, and reduced productivity than many other types of injury in the workplace.1 Fortunately, these are easily recognized and corrected.
Three fundamental ergonomic risk factors are position/ posture, repetition/duration, and force. These can all be influenced by the work area setup and the activity being performed. The good news is that these at-risk conditions that can cause pain and potential injury can often be easily controlled if one understands basic ergonomic concepts and how to apply them. In this article and the next, we will take a look at these factors and provide some practical solutions to help get you through the day pain-free.
The goal here is to achieve a balanced and neutral position. “Neutral” is typically thought of as the midpoint of range of motion for most joints (e.g., your wrists should be nearly straight in both the up/down and side-to-side axis, your upper arm should hang comfortably from the shoulder, your back and neck should be straight and not twisted or bent). Balanced in the ergonomic sense is when a posture or position is such that one does not have to fight (much) gravity to maintain that posture or position.
Let’s look at some of the most common positionrelated complaints we see. These are often the easiest to correct, and implementing changes can produce very dramatic improvements in one’s level of discomfort in a relatively short timeframe.
Your head weighs about as much as a bowling ball. Holding a bowling ball straight upright while resting your elbow on a table takes some effort. Now visualize that you are balancing a bowling ball (your head) on a cylinder (your neck). If you begin to tip the cylinder, it becomes harder and harder to support the ball. When you sit upright and are looking directly ahead, your skeletal structure supports most of the weight; if you deviate from a vertical position, your muscles must come increasingly into play to support your head. Now imagine tipping and lifting that bowling ball hundreds of times a day—that is exactly what you are doing when you are working from a hard copy placed on your desk. Your head goes up and down and side to side each time you look down at the paper and then up to the computer screen. Similarly, if your monitor is placed on the CPU so you must tip your head back to read (particularly problematic for those of you wearing bifocals), your muscles must support this off-balance posture. A much better approach is to place your hard copy on a document stand between the keyboard and monitor. The monitor should be directly in front of you, with the top of the screen just at or slightly below eye level. This way, instead of repetitive up/down and side-to-side head motion, one can look back and forth between the paper and the screen almost by using your eyes alone, allowing you to remain in a neutral, balanced position.
Holding the telephone receiver cradled between your ear and shoulder while doing other tasks is also a classic cause of neck pain if done on a regular basis. Hold the receiver in your hand if possible. Use a speakerphone or a headset if you must speak on the phone while working (such as when reviewing written materials or computer files).
Shoulder and neck pain
Hold your arm straight out in front of you for a couple of minutes. Now try drawing your shoulders up a couple of inches toward your ears and holding them there for a minute or two. In both cases you should begin to feel discomfort and fatigue relatively quickly. Both these examples illustrate stresses from an ergonomic standpoint that can occur when one is working with a keyboard and/or mouse on a surface that is too high or too far away. For many people this is a result of using a keyboard and/or mouse on top of a standard-height desk or having an older keyboard tray that doesn’t have room for the mouse (this also can cause contact stress issues we will discuss later). You must reach up, over the edge, and out in front to use the input devices. This might not cause an issue for really tall individuals, but we see it is being problematic for many average and shorter people. Ideally, when using a keyboard or mouse, your upper arms should hang comfortably at your side. The approach we most often take to remedy a case such as this is to recommend the installation of a combination keyboard/mouse tray.
A word of caution: a cheap tray will often not solve any problems—in fact, it may create new ones. We often see poorly designed trays collecting dust in storerooms because they just didn’t help. Look for a tray that has a “tilt to lift” feature or a large release button to move it up and down. In our opinion, one should stay away from units with twist knobs to lock and release; these create trouble, especially for people who are already having wrist and hand issues.
The mouse pad or surface is best positioned in the same plane as the keyboard; it is even better when it is placed where it can rotate over the keyboard or move toward you to reduce your reach and allow you to keep your elbows in while working. The keyboard platform is best kept level or sloped slightly downward (toward your thighs) so your wrists are straight (neutral) while typing.
We have started to explore the ergonomic risk factors associated with the use of computers. The take-home message here is “balanced and neutral.” Keep your monitor directly in front of you, with the upper edge at eye level or slightly below it. Place any hard copies in front of you on a document stand—either between the keyboard and monitor or immediately to the side of the monitor. Keep the keyboard and mouse in front of you and as close as is practical to prevent over-reaching. Make sure your wrists are as straight as possible in both axes. OSHA provides an excellent review of these guidelines through their e-tool on ergonomics.2 The state of Washington also has some very good self-evaluation checklists and online training guides.3 Look for Part 2 of this series on ergonomics, where we will discuss repetition and force as well as solutions to get you through the day pain-free.
1. Prevention of Musculoskeletal Disorders in the Workplace, US Department of Labor, Occupational Safety and Health Administration. Washington, D.C. https://www.osha.gov/SLTC/ergonomics/
2. Computer Workstations, US Department of Labor, Occupational Safety and Health Administration. Washington, D.C. http://www.osha.gov/SLTC/etools/computerworkstations/index.html
3. Office Ergonomics, Washington State Department of Labor and Industries. Tumwater, WA. http://www.lni.wa.gov/Safety/TrainingPrevention/workshops/WorkshopInfo.asp?WkshopID=53#description