Ergonomics as a science relies on anthropometry, biomechanics, kinesiology, physiology, psychology, industrial design, and mechanical engineering. Ergonomics in practice involves designing the workplace and its associated equipment to fit the needs of the human body. It is sometimes referred to as "human factors engineering." When the work environment fits the worker, musculoskeletal and repetitive motion disorders can be reduced and improvements in cognition and productivity can be realized.
The Office of Environmental Health and Safety (EH&S) is committed to fostering and supporting the health and well-being of the American University community. EH&S provides office ergonomic information and assessments to encourage healthy interaction between the employee and their work environment. Our ergonomics program is available to American University faculty and staff only. We are unable to accommodate requests from outside agencies currently.
To schedule an ergonomic assessment of your workplace, please click here.
EH&S does not diagnose injuries or illnesses or seek information regarding medical conditions, diagnoses, suspect conditions, physical therapy, or other medical appointments during any part of the evaluation process. When this type of information is provided by the requestor of his/her own volition, the details are not recorded, transmitted verbally, or placed in emails or memos.
The evaluator strives to provide options for adjustment or reconfigurations to the existing office equipment to reduce or eliminate repetitive motions and facilitate an office environment conducive to healthy postures. EH&S recommends the purchase of new equipment only when the current office equipment presents severely limited options for reconfiguration and adjustment or is defective.
The employee is encouraged to involve their supervisor throughout the ergonomic assessment process. EH&S does not have funds to purchase or install equipment. All recommendations are strictly optional and at the discretion of the employee's supervisor. It is the responsibility of the department to allocate resources as they see fit.
Setting Up Your Workstation
- Ergonomics is not one size fits all.
- To avoid unnecessary discomfort, make sure the following key principles are in place:
- When looking at your work, your neck should be in a neutral, relaxed position. Position the monitor directly in front of you to avoid turning your neck to the side.
- The monitor screen should be positioned so that you do not have to bend your neck up or down to see the screen. The top of the screen should be approximately 2-3" below seated eye level.
- The monitor should be positioned 20 to 30 inches away from you (slightly more than an arm’s length). Adjust as needed for your visual comfort.
- If you must use a telephone simultaneously with the computer, use a headset. Never try to hold the handset between your shoulder and ear. If you do use a telephone handset, position the telephone close to you to avoid over-reaching.
Your feet should be positioned flat on the floor or on a footrest if you do not reach.
Your chair should provide you with good back support. Maximize the contact of your back with the chair's backrest with the use of adjustments or cushions as needed.
It is often useful to have armrests. However, they should be adjustable in height and width to allow for resting arms and shoulders in a relaxed position.
The seat depth should be sufficient to provide support under your thighs. There should be approximately a two-finger width space between the edge of the chair and the back of your knees.
Your keyboard and mouse should be positioned at a height to allow for a slightly open elbow angle. Elbows should be at about a 100-degree angle. If you cannot adjust your keyboard height, raise your chair.
Your keyboard should be placed as flat as possible so that the wrists can be placed at a neutral position. (NOTE: Your sitting posture will affect how you adjust your keyboard and mouse. If you use a keyboard tray, it should be large enough to accommodate your mouse).
If you use a wrist rest, use it to support your palms only when pausing between keying. Do not place your wrists on the rest and turn your wrists from side to side to key. This increases the strain on your wrist.
Your mouse should be positioned within easy reach. Over-reaching can result in shoulder and/or arm discomfort.
Use a lighter touch on the keyboard to reduce impact on your wrists.
Place a document holder directly next to the computer screen if you will be referring to documents often while typing.
Follow the 20:20:20 rule. Every 20 minutes refocus your eyes on an object at least 20 feet away for 20 seconds. This will help reduce eye strain resulting from focusing on a single depth for prolonged periods of time.
Take frequent "microbreaks," at least every hour. This should be a moment when you stand up, stretch, strengthen, and adjust your seated posture. Static postures are bad for your circulatory system and muscles.
Tips for Laptop, Mouse, and Keyboard Use
Recommendations at a glance
- If you are a full-time laptop user, you should place your laptop on a riser so that the screen is at eye-level. Use an external mouse and keyboard to prevent wrist stress and overreaching.
- Whatever mouse you choose to use, position the device comfortably to the side of the keyboard and ensure that your wrist is in a neutral position when using it.
The design of laptops violates a basic ergonomic requirement for a computer, namely that the keyboard and screen are separated. In the early days of personal computing, desktop devices integrated the screen and keyboard into a single unit, and this resulted in widespread complaints of musculoskeletal discomfort. By the late 1970s several ergonomics design guidelines were written, and all called for the separation of screen and keyboard. The reason is simple: with a fixed design, if the keyboard is in an optimal position for the user, the screen is not, and if the screen is optimal, the keyboard is not in an optimal position. Consequently, laptops are excluded from current ergonomic design requirements because none of the designs satisfy this basic need. This means that you need to pay special attention to how you use your laptop because it may cause you problems.
Tips for Laptop Size and Mice
Using a laptop is often a trade-off between poor neck/head posture and poor hand/wrist posture. The following tips should help you avoid a laptop related musculoskeletal injury. The same posture principles apply to other input devices (e.g., trackball, touchpad, pen, digitizing puck, etc.).
The smaller the laptop, the smaller the keyboard, so make sure that you can comfortably type on a keyboard that may be only 75% the size of a regular keyboard.
If you plan on using a laptop as your primary computer, you may want to consider using an external, full-size keyboard to reduce ulnar deviation (outward bent wrists).
To avoid neck strain you should place your laptop on a riser so that the screen is at eye-level.
Hold the mouse gently to move it over a mousing surface.
Mouse from the elbow
Avoid skating or flicking the mouse with your wrist. Make controlled mouse movements using your elbow as the pivot point and keep your wrist straight and neutral.
Optimal mouse position
Sit back in your chair, relax your arms, then lift your mousing hand up, pivoting at the elbow, until your hand is just above elbow level. Your mouse should be positioned somewhere around this point.
Protect your wrist
If you look at the anatomy of the wrist it is curved away from any contact surface (you can easily see this by resting your hand/arm on a flat surface - you'll see light under the wrist and can probably even pass a thin pen under). The forearm is shaped like this so the exposed blood vessels near the wrist can remain free of surface pressure contact. Any pressure in this region will disrupt circulation into the hand and this will increase the risks of injury.
Do not rest your wrists on a hard surface
Placing your wrists on a hard surface (especially corners) greatly increases the pressure inside the carpal tunnel, causing it to become inflamed. This inflammation can lead to chronic pressure and pain on the median nerve, which supplies feeling and movement to parts of the hand.
Avoid restricting arm movement
With a softly padded wrist rests, especially one that is rounded, or a soft chair arm rest, the forearm becomes "locked" into position. This encourages mouse movement by flicking the wrist, which can increase pressure on the carpal tunnel.
The base of the palm of the hand (not the wrist) is the part of the body designed to support the hand when resting on a surface. With a keyboard, the best palm posture is for users to float their hands over the keyboard when typing and then to rest palms during micro-breaks between typing bursts. With a mouse, the palm ma rest on the surface but movements should be made using the elbow as the pivot point, not the wrist. Anything that impairs free movement of the forearm/hand and mouse will increase injury risks.
Try to choose a mouse design that fits your hand but is as flat as possible to reduce wrist extension. A symmetrically shaped mouse is usually preferred to a curved mouse.
If you want to load share between your left and right hands (that is, use the mouse for some of the time with each hand), a symmetrically shaped mouse that can be used by either hand.
For more information, please contact:
Environmental Health and Safety