Office Ergonomics
Many people don’t realize that a poorly designed computer workstation and/or bad work habits can result in serious health problems. Common symptoms associated with poor design or habits include discomfort in the back, neck and shoulders, hands and wrists, as well as headaches and eyestrain. If you experience any of these symptoms while working, contact the University Employee Occupational Health Clinic (UEOHC) for medical help.
Fortunately, the solution can be quite simple. Proper workstation setup and work practices can eliminate discomfort and even prevent it from occurring in the first place! Simple adjustments to office equipment can work wonders, making work more comfortable and more productive.
What To Look For In A Chair
Starting from the bottom and moving upwards:
- The seat pan depth should be adjustable to provide a fist-width to three-finger gap between the back of the calf and the front edge of the seat pan. If the seat pan is too shallow, all the pressure from sitting is placed on a small part of the thighs, which may lead to discomfort. If the seat pan is too deep, it will either be difficult to use the backrest or the front of the seat will put pressure on the back of the nerves and tendons at the backs of the knees.
- The seat pan should be able to tilt backwards and forwards. Changing your posture throughout the day is positive because when you change postures, the loads of sitting shift to different parts of the body, allowing your body to recover from extended static postures.
- The seat pan should have a waterfall (rounded) front edge. Sharp corners, even when they’re made of padding, increase the pressure on the backs of the thighs. A rounded front edge distributes the pressure over a larger area.
- The backrest should be able to recline independently of the seat pan and be set at a fixed reclined angle. It is acceptable to sit upright or recline slightly in your chair as long as the backrest is designed for reclined seating. A slightly reclined posture opens up the angle between the hips and trunk, which decreases the stress placed on the low back.
- The armrests should be adjustable in height. If the armrests are too high, you might have to shrug your shoulders in order to use them, which could fatigue your shoulders and back. Conversely, if they are too low, then you might end up leaning on one armrest.
- They should be rounded on the edges. Sharp corners, even when they’re made of padding, increase the pressure on the arms. A rounded edge distributes the pressure over a larger area.
- Optional: most armrests are spaced too widely apart for the user to use them comfortably. Armrests that are width-adjustable to slide over the seat pan until they are right under the elbow or armrests that pivot inwards (the kind that can pivot almost all the way around are preferable) are much more functional than simple height adjustable armrests. If the armrests are spaced too far apart, they will not be directly under the elbows. In order to use the armrests, users have to hold their arms slightly away from the body. This reach can fatigue the shoulder muscles.
Characteristics | Adjustments | Explanation |
---|---|---|
Seat | Height | Seat height and depth are the two most important features here.
|
Depth (seat slider) | ||
Backward tilt | ||
Forward tilt | ||
Backrest | Height |
|
Angle | ||
Tension | ||
Armrests | Height | Armrests are not always necessary and nonadjustable armrests can be actively disruptive if they force the user to raise or lower their shoulders to use them or block the user from easily reaching objects, such as the computer mouse.
|
Width | ||
Pivoting | ||
Lumbar Adjustability | Firmness | This feature is becoming more and more common in office chairs.
|
Height | ||
Size of Curvature | ||
Material | Waterfall Seat | Most new office chairs have these features.
|
Rounded Edges on Armrests | ||
Padded Armrests | ||
Impression | Safety |
|
Opinions |
Why Not To Use An Exercise Ball For A Chair
Considering using an exercise ball as your office chair? Think again. What may seem like a good idea to you or others is actually not recommended. Read the following articles for further information:
- Replacing Office Chairs with Exercise Balls by Heather Ritz
- Opinion: Balls as Office Chairs a Bad Idea
Setting Up My Chair
Start out adjusting a chair from the ground up. Start with the height and move up from there. While adjusting the chair, worry first about getting the chair adjusted to fit you. Afterwards, look at things like the height of the desk, keyboard, etc. Too often, people adjust a chair too high so they can reach the keyboard rather than properly adjusting the chair and adding a keyboard tray to move the keyboard to the correct height.
Height
Start by adjusting the height until your thighs are parallel to the floor. Stand in front of the chair and adjust the height until the top of the seat pan is at the height of the bottom of your kneecap. Then, sit in the chair and make small height adjustments until your thighs are parallel to the ground. Sit in this position for a while before making any further changes in seat height. When you have become accustomed to this height, adjust the chair height up/down one to three inches until you find a location that is comfortable for you while seated (don’t worry about that keyboard height yet!).
Depth
Adjust the seat pan until you have about three fingers to a fist’s width of room between the back of your calf and the front edge of the chair when your back is touching the backrest. If the seat pan is not adjustable and the pan is too deep, add padding to the backrest (a towel over the backrest of the chair or a backrest cushion) to shift you forward in the seat while maintaining contact with the backrest. If the seat pan is too shallow, start looking for a new chair.
Angle
There are three basic postures. The standard posture calls for a level seat pan so it is not necessary to adjust the tilt for this posture. Likewise, the reclined posture can have the seat flat as well. However, some people prefer to have a very slight backward tilt on the seat pan to help keep them in the seat. In the forward tilt posture, the seat pan is tilted forward 5-10°. Start by raising the overall height of the chair a few inches, and then tilt the seat pan forward.
Height
The lumbar curve on the backrest should fit into the small of your back. Start by raising the chair back as high as possible and then move the backrest downward in small steps until it feels most comfortable. If the chair doesn’t have enough lumbar support consider adding a lumbar pad to the chair. Make sure the extra pad doesn’t make the seat pan too short!
Angle
In the standard posture and forward tilt postures, the backrest should be straight up. If it feels as though the chair is pushing you forward, adjust the backrest back until you feel upright. In the reclined posture, the backrest should be reclined slightly. When seated, the angle between the thighs and back should be more than 90°.
Height
Sit in the chair with your arm bent 90° and raise the armrest until it is directly under your elbow. Repeat the process with the other arm and then check that the armrests are the same height.
Width/Pivot
Some armrests pivot or slide inwards, allowing you to change the angle and width of the armrests. Adjust the armrest inwards until it is directly under your elbow while your upper arm/shoulder is relaxed. You should not have to reach your elbows outward to reach the armrests. If the armrests pivot, pivot them slightly inwards so they are underneath your forearms when you reach inwards to the keyboard.
This video guides the viewer through the steps involved in ergonomically adjusting their task chair to their workstation and body dimensions. Special thanks to Kim Haley and Larry Daw.
What To Look For In A Footrest
Use footrests as a last resort. Footrests are a way to shift postures or provide support for the feet if the chair cannot be lowered. Unfortunately, using a footrest when the chair is too high provides only one place for the feet to rest. The seated person only has the footrest and the castors under the chair as places for their feet and this limits the postures they can shift through throughout the day. The preferred solution is to add a shorter cylinder to the chair and lower the desk height until the desk surface is approximately one inch above seated elbow height.
What To Look For In A Keyboard Tray
The purpose of a keyboard tray is to change the height and angle of the keyboard without interfering with how the user uses the keyboard and mouse. Therefore, the tray should be easy to adjust, have enough room for the keyboard and mouse and not prevent the user from typing with the keyboard at forearm length from the body.
Setting Up My Keyboard Tray
What To Look For In A Keyboard
There are many keyboard designs available. The two most common keyboard designs are the standard flat keyboard and the split keyboard.
Setting Up My Keyboard
Location
The number pad creates an optical illusion when aligning the keyboard and monitor, particularly with standard keyboards. The monitor is usually lined up with the center of the entire keyboard (approximately the ‘;’ key). The user, however, sits lined up with the center of the letters portion of the keyboard (approximately the ‘g’ and ‘h’ keys). This causes the user to either twist slightly to face the monitor or sit centered to the monitor and reach to the side to use the keyboard. When seated at the workstation, align the “gh” keys with the bellybutton and also check that the “gh” keys are centered with respect to the monitor.
What To Look For In A Mouse
The first decision to make is what kind of input device to get. Users grip standard mice and move them to move the cursor on the screen. With a trackball, the user rolls a ball mounted on a stand to get the same effect. Touchpads require the user to move a finger on a small touch-sensitive square to move the cursor. Other input devices mount in front of the keyboard, use a pen on a large touch-sensitive square or even combine hand gestures to interpret commands.
After deciding on the input device, look for the features it offers and how well it fits the hand.
About Wrist Rests
Wrist rests are intended to promote straight wrists and reduce pressure on the wrist by providing a soft surface to rest upon. However, research studies by Parsons (1991), Paul and Menon (1994) and Horie et al. (1993) indicate that foam wrist rests create similar pressures on the wrist as not having a wrist rest. Wrist rests that are higher than the keyboard or too narrow can actually be worse than no wrist rest at all.
Like chair armrests, wrist rests are “rests,” not “supports”. Too often, users support their wrists with the wrist rest continuously while keying and mousing. In addition to exposing the wrists to constant pressure, this static position forces the typist to stretch the fingers and bend the wrist to reach keys at the sides of the keyboard.
Wrist rests are best used when there is a sharp edge or hard surface the user is constantly coming into contact with. They should be used to rest the wrists during pauses while typing and not used as a continuous support.
What To Look For In A Wrist Rest
What To Look For In A Monitor
Setting Up My Monitor
What To Look For In A Glare Screen
When shopping for a glare screen, consider your need. Glare screens reduce light reflected into your eyes from the screen and reduce washing out of images on the screen. Privacy screens are used to prevent others from seeing the computer screen while standing to the side of the computer. Some screens combine both features.
Use a glare screen only when you cannot position the monitor away from glare-producing light sources or turn off lights that shine on the screen. Using a glare screen is similar to wearing a pair of sunglasses while looking at the monitor. Everything is darker, including images on the screen!
Setting Up My Glare Screen
After putting the screen in front of the monitor, check to see if reflections on the screen are reduced. Next, look through the screen to the monitor. Is the monitor darker? Adjust the brightness and contrast controls on the monitor until you can comfortably view the monitor again.
What To Look For In A Document Holder
The purpose of a document holder is to hold reference documents as close to the computer screen as possible, and at about the same angle. This will eliminate a twisted working posture, and also put the document at an easier-to-read angle. Constantly reading from a hard-to-read angle can be hard on the eyes.
Document holders usually either clip to the side of the monitor, sit beside the monitor, or rest in front of the monitor.
When Do I Need A Headset?
Users who frequently use the phone and computer simultaneously or are on the phone for extended periods of time should consider a headset. Headsets attach to the head like a single headphone with a mouth piece or attach directly to the ear. Headsets reduce the tendency to cradle the phone and allow the user to work with both hands while conversing on the phone.
What To Look For In A Headset
Headsets are either cordless or corded and both come in traditional headphone and over-the-ear configurations. In addition, the University phone system is compatible with specific headsets. Check with the manufacturer or retailer of any headset before purchasing.
Cordless vs. Corded
Cordless headsets compatible with the University phone system come in one- and two-line configurations. Corded headsets are compatible with phones using any number of phone lines.
Frequent Travel
These recommendations are for users who frequently travel and spend substantial time using a notebook computer while on the road.
When purchasing a notebook computer, consider the weight of the entire system, not just the notebook alone. Some ultralight notebooks require so many additional accessories that they end up weighing the same as a regular notebook.
Solution: portable keyboard/external mouse. There are many portable keyboards available. These keyboards range from regular keyboards that fold in the middle for travel to flexible roll-up keyboards. When purchasing a portable keyboard, look for keyboards with full-size keys and ask yourself if you need the numeric keypad to the right of the keyboard. If you don’t need it, you might look for a keyboard without the keypad to save space and weight! Most external, desktop-style input devices are small and light enough to travel with you. Do not sacrifice comfort for size when looking for a traveling input device. If you choose a mouse, consider an optical mouse. Optical mice do not need a mouse pad to operate correctly, making them more versatile for use while traveling.
Solution: Portable keyboards. There are many portable keyboards available. These keyboards range from regular keyboards that fold in the middle for travel to flexible roll-up keyboards. When purchasing a portable keyboard, look for keyboards with full-size keys and ask yourself if you need the numeric keypad to the right of the keyboard. If you don’t need it, you might look for a keyboard without the keypad to save space and weight! Most external, desktop-style input devices are small and light enough to travel with you. Do not sacrifice comfort for size when looking for a traveling input device. If you choose a mouse, consider an optical mouse. Optical mice do not need a mouse pad to operate correctly, making them more versatile for use while traveling.
As a Desktop Replacement
In some offices, the notebook computer has entirely replaced the desktop as the primary computer. Sometimes the notebook travels between a home office and a work office, in which case read the section on notebook weight.
Keyboard, Mouse and Monitor too Close to Each Other
Notebook computers can be used as a replacement for desktop systems. However, they are not stand-alone replacements. The keyboard and monitor on a notebook are too close together. When computers were first designed, the keyboard and monitor were very close to each other. This caused users to either hunch down to see the monitor, hold their arms uncomfortably up to reach the keyboard, or a combination of both. As computer design advanced, the designers separated the monitor and keyboard so they could be more comfortably placed.
Solution: External Keyboard/Monitor. Do the same with a notebook replacing a desktop as you would with a desktop: add a keyboard and possibly a monitor. If the notebook monitor is large enough, the notebook monitor can be used. Be sure to set up the monitor in the same way you would a stand-alone monitor. Use whatever external keyboard and mouse with which you are most comfortable.
Glare
There are three types of glare: direct, indirect and contrast.
Try to place the monitor perpendicular to windows and light sources. Point lamps at walls or the desk to diffuse the light source and keep the light from shining directly into the eyes. Be careful when shining lights onto a desktop. Some desks are highly reflective and can cause indirect glare.
To test for direct glare, use your hands to shield your eyes from light from above you and to the sides (windows and lights). If your eyes feel more comfortable shielded, look for light sources that could be shining into your eyes. Selectively shielding your eyes (i.e. only from one side for example) can give you ideas on where to look for the offending light source.
We recommend taking about 20 seconds to one minute of break every 30 minutes. You should also break up your sitting period by walking to the water fountain, printer, etc.
First, a good exercise would be to stretch muscles that are opposing the ones you normally use. This will allow you to achieve a balance within muscle groups. For example, if you regularly use your biceps muscle, along with stretching it, you can also stretch your triceps muscle.
Here are some other exercises:
- Clench your hand into a fist and release, fanning out the fingers. Repeat three times.
- With elbows straight, bend your wrists down as far as they will go, hold for three seconds then extend your wrists back as far as they will go. Do five times.
- Stand up straight, place your hands on your hips and bend backwards at the waist, gently. Do five times.
- Touch the fingertips of your hands together just behind the top of your head without letting your hands touch your head, move your elbows in a backward direction, hold five seconds then relax. Do three times.
- Tuck your chin in while keeping your eyes level; hold three seconds and then relax. Do five times.
- Roll your head in circles, stretching more toward each shoulder. Do five times.
- Eyestrain tip: Blink often, and take frequent rest pauses; close your eyes for a minute, refocus by looking away from your monitor at something in the distance, and roll your eyes up and down, left to right.
- General Windows Shortcuts
- Windows Keyboard Shortcuts: If your keyboard has a Windows key, you can make use of these shortcuts as well.
- Shortcuts That Work in Most Programs
- Shortcuts for Microsoft Word
- Shortcuts for Microsoft Excel
- Shortcuts for Common Browsers
In addition to the above shortcuts, users can sometimes find the shortcut keys to their most popular program by looking for them in their menus. Some menus will have an underlined letter on a menu item. This indicates that the user can press the Alt key and the underlined letter to access that menu item as a shortcut. Sometimes, hovering over a button in a program may tell you the shortcut, or shortcuts may be listed right next to the menu item itself. Links to shortcut resources can sometimes be found in a program’s Help section. As you begin to work with shortcut keys, you will notice that several applications share the same shortcut keys.
Additional Resources
- OS X Keyboard Shortcuts (for Apple computers)
- Xcode Keyboard Shortcuts and Gestures (for Apple software developers)
- Explanation of Keyboard Shortcuts (Wikipedia)