Ergonomic Tips: Workstation
1. Adjust your chair and other workstation components every time you sit down.
2. A study was done indicating that more controls on an ergonomic chair meant longer time to make the adjustments. However, they also found that more adjustment features meant greater user comfort. Take the time to adjust all of the chair features across the work day.
3. If any of the adjustment features of your chair or workstation are not working properly, contact your supervisor immediately.
4. The body is made to move - change your posture during the course of the day.
5. If you sit all day long and do not change your posture, lactic acid accumulates in muscles. Lactic acid is a waste product produced by muscles, and pain is the sensation we feel as a result of lactic acid accumulations. Changing postures reduces the build- up of lactic acid.
6. Stand during the day. Sitting can place more pressure on the low back than standing.
7. Arrange your work area to promote occasional standing. Place your printer or files in a position so you will have to get out of the chair to access them.
8. When you stand during the day try to walk around to facilitate blood circulation.
9. When you stand up, try to prop a foot up on a foot rest in order to maintain the natural curvature of the spine (the Lazy S Curve).
10. Cushioned insoles are available for shoes that can make standing less fatiguing for the worker.
11. Even when you are sitting, don't sit while sitting! Change your seated posture and chair adjustment settings throughout the work day. This is referred to as "cyclical sitting".
12. Arrange your work so that you don't have to lean forward in your chair to reach objects. Keep those objects you most frequently handle within 15" of the front edge of the table, and in the plane defined by your shoulders.
13. Arrange your work so that you don't have to lean forward in chair to reach objects. Why is this important? Back muscles work nearly 100% harder when you lean forward in a chair, versus leaning back and using the back rest on the chair.
14. Don't set reference documents in front of the keyboard. This results in extended reaches whenever the keyboard is used.
15. Arrange your workstation so that the work is always in front of you. Avoid placing work so you have to reach behind the body mid-line to reach it. This is referred to as shoulder extension, and is very stressful on the shoulder joint.
16. If you have to write down or record information in addition to using the keyboard, it is best to arrange the writing area so that it is at a 45 degree angle to the keyboard, on your writing hand side.
17. Ergonomic Terms: Flexion refers to closing (making smaller) the angle at a body joint. Shoulder flexion refers to reaches in front of the body. Neck flexion refers to looking down. Wrist flexion refers to bringing the palm of the hand closer to the underside of the forearm. Back flexion refers to bending at the waist.
18. Ergonomic Terms: Extension refers to opening (making larger) the angle at a body joint. Shoulder extension refers to reaches behind the body mid-line. Neck extension refers to looking up. Wrist extension refers to bringing the back of the hand closer to the top side of the forearm. Back extension refers to leaning back at the waist (arching the back).
19. Ergonomic Terms. Wrist deviation refers to side-to-side movements of the hand. If the hand bends towards the thumb side of the hand, this is referred to as radial deviation (it's called this because you are deviating the wrist towards the radial side of the forearm). If you bend the hand towards the opposite side, it's called ulnar deviation (deviating towards the ulnar side of the forearm).
20. Ergonomic Terms. Shoulder Abduction refers to moving the elbows out away from the sides of the body (to visualize this, imagine flapping your arms like a bird).
21. Ergonomic Terms. Forearm pronation refers to working with the palms of the hands facing down (the posture we assume when typing).
22. Ergonomic Terms. Forearm supination refers to working with the palms of the hands facing up (the posture your hands would assume if carrying an object from underneath).
23. When adjusting your chair and workstation, the general design goal is the NEUTRAL POSTURE. The neutral posture is that posture which minimizes stresses on the joints. Sitting or standing in the neutral posture allows us to work longer and more productively without experiencing excessive fatigue.
24. When adjusting your chair and workstation, try to achieve the neutral posture. The neutral posture for the neck consists of the head being in an upright position. The neck should not be bent forward (flexed) or back (extended). The neck should not have to rotate to look at the monitor or source documents.
25. If you spend long periods of time with your neck flexed, extended, or rotated, ligaments stretch and weaken. Ligaments are the connective tissues in our bodies that connects bones to other bones. A weakened ligament makes the body more susceptible to injuries.
26. Because CTDs so often occur in the hands and wrists, we often overlook neck posture as a contributing cause or risk. There are health professionals who feel that awkward neck postures can trigger CTDs "downstream" in the body.
27. When adjusting your chair and workstation, try to achieve the neutral posture. The neutral posture for the shoulders and arms consists of the shoulders being relaxed and hanging loosely at your sides. The elbows should be at about a 90 degree angle with the forearms about parallel with the floor, and the wrists should form a straight line with the arms, hands, and fingers.
28. When adjusting your chair and workstation, try to achieve the neutral posture. The neutral posture for your back consists of sitting with a minimum of a 90 degree angle between your trunk and thighs (never less!). Most guidelines recommend at least 100 degrees for this angle.
29. If you are sitting and the trunk-thigh angle is less than 90 degrees, pressure on the low back increases significantly. It also causes pressure points in the buttocks that can increase discomfort.
30. The back should always be in contact with the back rest of the chair. This is especially important for the low back area (the inward curved area in the low back).
31. Many chairs have three back rest adjustment features. The back rest can adjust vertically (up-down), horizontally (back-forth), and back rest tension can be adjusted. Take advantage of all of these features in order to achieve good low back support.
32. When seated, you need good low back support. But where is the low back? Stand up and place your thumbs on your hip bones and place the fingers in your back. Where the fingers are touching - this is the low back area and it is critical that the chair provide good support for this region.
33. When adjusting your chair and workstation, try to achieve the neutral posture. The back should maintain a "Lazy S Curve" when seated (the upper back is curved slightly outward, the low back curves in, and the base of the spine curves out). Proper positioning of the back rest helps you maintain the Lazy S curve.
34. When adjusting your chair and workstation, try to achieve the neutral posture. For the legs, the neutral posture consists of having at least a 90 degree angle at the knees (never less!), the seat pan of the chair should extend almost to the inside of your knees but not press against the inside of the knees, and the feet should rest comfortably on the floor or a foot rest.
35. If your workstation has an adjustable chair and an adjustable work surface (adjustable keyboard tray, etc.), you should position yourself at the workstation by first adjusting the seat height so that your feet are flat on the floor, then adjusting the keyboard height so that your arms are in the neutral posture.
36. If your workstation has an adjustable chair and a fixed-height work surface, you should position yourself at the workstation by first adjusting the seat height so that your arms are in the neutral posture at the keyboard, then adjusting for leg position (e.g., getting a foot rest if your legs are dangling).
37. Vertical Leg Clearance. Your legs should fit comfortably underneath your work surface without physical contact. If you have adjusted your chair and workstation and your legs do not "fit" underneath the work surface, consider raising the work surface using blocks or some other elevation device.
38. Vertical Leg Clearance. Your legs should fit comfortably underneath your work surface without physical contact. If you have adjusted your chair and workstation and your legs do not "fit" underneath the work surface, consider removing the drawer to increase vertical leg clearance.
39. Horizontal Leg Clearance. Your legs should have room to stretch out in the leg well underneath your work table. If you cannot stretch out your legs, try to remove any materials (work or personal) that you may store in the leg well. The leg well of your table should not be used as a storage area.
40. Horizontal Leg Clearance. Your legs should have room to stretch out in the leg well underneath your work table. If they cannot due to cabling or electrical outlets in the leg well, try to re-route the cabling or move the desk.
41. Horizontal Leg Clearance. Horizontal leg clearance also applies to the ability to move the legs from side to side in the leg well of your work station. If your legs are "locked" due to inadequate clearance from side to side, sitting and twisting may occur. Avoid placing objects in the leg well that will limit your ability to move the legs from side to side.
42. Work surfaces should be kept slim (about 5 cm from top to bottom of work surface) in order to promote the neutral posture. A thicker work surface makes it more difficult to achieve adequate leg room and keep the arms neutral at the keyboard. If your work surface is thicker than 5 cm due to a drawer at the table, see if the drawer can be removed.
43. Ergonomic Terms. Anthropometry is the study of the physical dimensions of the human body (How tall are people? How much do they weigh? How far can they reach?) Anthropometric data are used to design computer workstations that can accommodate a large portion of the population.
44. Ergonomically designed workstations are typically designed to accommodate a specified range of the population from the 5th percentile female to the 95th percentile male. The 5th percentile female refers to the smallest 5% of the population (only 5% of females are smaller than the 5th percentile female). The 95th percentile male refers to the largest 5% of the population (only 5% of males are larger than the 95th percentile male).
45. There are three "golden rules" of anthropometry that drive workstation design. 1) Where possible, make things adjustable. 2) Design clearances to accommodate the 95th percentile male. 3) Design reaches to accommodate the 5th percentile female.
46. How much room should you have at your workstation? The horizontal space (depth) at knee level should be at least 46 cm (15 inches). At foot level, this required depth increases to 61 cm (26.5 inches).
47. How much room should you have at your workstation? The width of the leg well should be at last 51 cm (20 inches) so the legs can move from side to side.
48. How much room should you have at your workstation? The distance from floor to the bottom side of the work surface should be 63 cm (about 26 inches). This will provide adequate vertical leg clearance for the largest segments of the population. If you are a smaller person, you may not need this much vertical leg clearance.
49. How much room should you have at your workstation? If you have an adjustable keyboard tray, it should adjust from approximately 55 to 75 cm. This adjustment range will accommodate over 90% of the population.
50. How much room should you have at your workstation? In order to stand and use the keyboard without bending or placing the wrists in awkward postures, the keyboard should be adjustable up to at least 36 inches.
51. How much room should you have at your workstation? If you have your keyboard on a fixed-height work surface, that surface height should be 75 cm (30 inches). This height is based on the largest segments of the population. If you are a smaller person, you may not need this high a work surface If it is this high, you may need to adjust your chair as high as it will go, and use a foot rest..
52. What is an Ergonomic Chair? Typically we define an ergonomic chair as having the following features: 1) Easy Adjustability (you can adjust the chair while seated in the chair), 2) Good Support (both from seat pan and back rest), and 3) a 5 prong base to minimize tipping.
53. An ergonomically-designed chair is designed to "fit" about 90% of the population. This means that if you are an extremely large or small person (i.e., you fall outside the 90% design specification), you may not find that the chair fits you. For example, a vary short person may still need a footrest even with an ergonomically-designed chair.
54. An ergonomically-designed chair is best suited to reduce low back discomfort. A well designed chair is less likely to prevent upper extremity Cumulative Trauma Disorders (CTDs).
55. There is no one "best chair" on the market. The best chair is the one that fits you and supports the tasks you perform.
56. Ergonomically-designed chairs are available with active and passive adjustment features. Active adjustment means you have to make the adjustment. Passive adjustment means the chair "adjusts" automatically in response to your movements in the chair. Although passive adjustments sound like a great idea, in general active adjustments are better for you (i.e., you have more ability to adjust the chair properly).
57. Not only can properly-designed and adjusted chairs increase comfort and productivity, but they have been shown to have a positive emotional effect on workers.
58. As a general rule, the seat height should have enough adjustability so that the seat pan can raise to 10 inches from the bottom side of the worktable.
59. The seat pan of your chair provides the most support for your body (about 65% of your body weight is supported through the seat pan). The larger the seat pan, the more support provided.
60. Ergonomic Term. The popliteal tendon is the large tendon in the back of the leg, connecting the lower and upper leg. Sit down, reach behind your leg, and you can feel these tendons. The seat pan should never press against these tendons, in that discomfort can result.
61. To avoid pressure on the back of the legs, the seat pan should have a waterfall front (the front edge of the seat pan should curve down).
62. To avoid pressure on the back of the legs, the seat pan should not be too long (i.e., it should not physically contact the back of the legs). As a general rule, you should be able to slide your hand between the front edge of the seat pan and the back of your leg.
63. Avoid a seat pan that is too soft. While this may feel comfortable initially, it can end up being uncomfortable over time. The seat pan should have some firmness and should depress about 1" when you sit in it.
64. Some chairs have a seat pan that will tilt both backwards and forwards of horizontal. A forward sloping seat pan increases the angle between the trunk and thighs and can reduce pressure on the low back.
65. If you are using a chair that is not adjustable up or down, a seat cushion might allow you to obtain a proper seated height.
66. If you are using a chair where the seat padding is worn (e.g., "bottoms out" when you sit in it), consider a seat cushion to improve comfort when seated.
67. A chair should have casters to promote ease of movement on the part of the user. A 5-prong base is recommended.
68. Lack of adequate back support is one of the most common problems observed among seated workers.
69. How important is a good back rest on a chair? The back muscles work about 33% harder without a back rest than with a back rest.
70. A high (large) back rest is preferred over a small back rest, because it will allow more of the back to be supported.
71. The back rest of the chair should be able to recline 20-30 degrees relative to the seat pan.
72. The contours of the back rest should follow (thereby support) the contours of the back.
73. If you have adjusted your chair and your back does not contact the back rest of the chair, consider getting a lumbar pad for the chair. A lumbar pad basically extends the back rest out so you can get proper back support.
74. A lumbar pad can consist of something as simple as a rolled-up towel placed in the low back area, but in general a large lumbar pad is recommended over a smaller pad.
75. If you adjust your chair and your back contacts the back rest, you do not need a lumbar pad. The lumbar pad in this case only serves to shorten the seat pan length and reduces the support your legs are provided.
76. Seat tension adjustments allow different-sized persons to lean back while maintaining good back support.
77. If you adjust your chair height and your feet are not touching the floor, consider getting a foot rest to provide proper leg support.
78. A well-designed foot rest should be large enough to support and allow both feet to move (in other words, it does not "lock" the feet into one position), and it should be covered with a non-slip material.
79. Ideally, a foot rest should have adjustability, both in terms of height and angle. An adjustable foot rest should allow the foot to rotate about the ankle. If the foot rest does not have this adjustment feature, it should be oriented at about 20 degrees.
80. Arm rests are a recommended feature on chairs. Arm rests can reduce pressure on the wrist area, and in general reduce muscular requirements in the arm, shoulder, and neck region.
81. If arm rests are too large, they can get in the way rather than help you. Many chairs allow arm rests of different sizes to be installed. Select the size that benefits you and the tasks you perform.
82. The back rest of the chair is one of the most advantageous features of a well- designed chair. It reduces the amount of work the back muscles need to do during the day. For this reason, a kneeling chair is not recommended if you spend a lot of time at the computer.
83. Use a document holder so that you do not have to view documents laying flat on your work surface. Looking at a document laying flat on the table can cause neck flexion.
84. Try to position the document at approximately the same distance and height as the computer monitor. The document holder may have to come closer if you are required to reach for the documents routinely. Reach distances should not exceed about 15".
85. If the source document is the primary reference point, place the source document directly in front of you with the monitor slightly to the side.
86. Tips for selecting a Document Holder. If you have to reference individual lines on a document, the document holder should have a ruler attached. If you work from books, get a document holder with a book holder feature (keeps the book open).
87. Tips for selecting a Document Holder. If you have to read very small print off a document, there are document holders with magnifiers built in.
88. Tips for selecting a Document Holder. The document holder should be slightly smaller than the documents it holds, in order to allow you easy access to the documents.
89. Tips for selecting a Document Holder. The document holder should be a dull matte finish to avoid glare.
90. A wrist rest at the keyboard is recommended in order to reduce pressure on the wrist, and to keep the wrist in a straight posture.
91. When you rest your hands on the wrist rest, the base of the palms should contact the wrist rest, not the wrist itself.
92. When selecting a wrist rest, avoid a wrist rest that is too soft.
93. When selecting a wrist rest, select one with a low coefficient of friction (in other words, the hands should travel easily over the surface of the wrist rest).
94. Select a wrist rest that can be easily cleaned.
95. The wrist rest should be positioned at the keyboard so that the surface of the wrist rest is level with the front edge of the keyboard. This helps keep your wrists straight when using the keyboard.
96. When selecting a wrist rest, select one with a narrow profile (in other words, do not select a deep wrist rest that will result in increased reach distances to the keyboard).
97. If you use a trackball, use a wrist rest for this input device as well as the keyboard.
98. If you use a mouse, you may not need a wrist rest, since the arm travels with the mouse rather than rests on the mouse. However, there are wrist rests available for mice if you feel more comfortable with one.
99. Avoid extended reaches to the phone. If you cannot bring the phone within 15" of the front of the table, consider a foot-activated control.
100. Always select a writing instrument that you can comfortably grasp. Consider a slip- over sleeve for conventional pens that increase the diameter and improve grip.
101. Always lay down the writing instrument when not in use.
102. Always lay down the writing instrument when using the keyboard or the mouse.
103. When writing, do not press any harder than is necessary.
104. Monitors that are too high, and result in the Agent having to look up at the monitor, are one of the most common ergonomic problems in Call Centres. A monitor that is too high results in increased neck and visual fatigue.
105. The monitor should be positioned so that the top line on the screen is no higher than your horizontal line of sight. In general, lower is better when positioning the monitor.
106. Removing the CPU from underneath the monitor is a good way to lower a monitor that is too high.
107. If the monitor is too low, look for something to place underneath the monitor to raise it.
108. If you wear bi-focals, it is very important to keep the monitor as low as possible to minimize extreme neck postures.
109. The viewing distance to the monitor will be dictated by the character size on the screen. There is no upper limit to how far away you can place the monitor, other than your ability to read the characters on the screen.
110. Do not place the monitor closer than 18" in front of you.
111. It is preferable to increase the size of characters on the screen rather than moving the monitor closer to you.
112. The minimum recommended font size for the computer screen is 12 point.
113. If the monitor is too close to you for comfortable viewing, and you can not move the monitor farther away, consider installing an adjustable keyboard tray. The keyboard tray will effectively move you farther away from the monitor, by moving the keyboard out away from the work table.
114. The monitor should always be positioned so that it is directly in front of you. You should not have to rotate your neck to view the monitor. This is referred to as keeping the monitor in-line with the body.
115. Tilting the monitor forward is often proposed as a method to reduce glare on the screen. However, studies have indicated that neck discomfort increases when this method is used. Do not tilt the monitor forward of vertical to reduce glare.
116. If you have lowered the monitor to place it in your primary viewing area, you may find that the monitor cannot tilt back far enough to achieve a 90 degree angle with your line of sight. Placing a book or other elevation device underneath the front edge of the monitor may help you achieve the ideal viewing angle. (But also remember that, as you tip the monitor back, glare may become more pronounced)
117. Keyboards should be easy to reposition on the work surface. Make sure the keyboard cord is long enough to allow you to move the keyboard as desired.
118. Keyboards should be light-weight, but the keyboard should sit firmly on the work surface without sliding or "jiggling".
119. Keyboards usually have feet at the rear of the keyboard that can be extended to change the angle of the keyboard. Sometimes we think that these feet are supposed to be extended, simply because they are there. Extend or retract the feet as needed in order to keep the wrists straight when using the keyboard.
120. If you have a keyboard tray that allows it, try sloping the keyboard away from the hands (i.e., front edge of keyboard is higher than rear edge). This is referred to as a negative slope. Studies have indicated that this can reduce muscular efforts. Note that the negative slope requires the elbow angle to be greater than 90 degrees, and the hands will be slightly below elbow level.
121. There are a variety of ergonomic keyboards on the market. Usually they are designed such that the 2 halves of the keyboard are split to allow the wrists to maintain a straighter posture, or the sides form an inverted V that reduces rotation at the elbows. The health and productivity of these ergonomic keyboards is questionable. It is far more important to look at how you work on your present keyboard, than to get a different keyboard.
122. Ergonomic (split) keyboards may be of benefit to large persons (either very wide shoulders or obese workers). These users may benefit more from the angled key orientation because, due to their size, they tend to work with the wrists more deviated at a conventional keyboard.
123. If you are left handed, get a mouse designed for the left hand. Or program the mouse for left-handed use.
124. If you are left handed, consider a detachable 10-key pad so you can use it with the left hand.
125. Keep the mouse or trackball immediately next to the keyboard to avoid extreme arm postures.
126. Place the mouse directly in front of the arm directing the mouse. This may involve repositioning the keyboard slightly to the side if you are going to be using the mouse for any extended period.
127. When you are not typing or using the mouse, take your hands off the keyboard and rest your arms. Don't keep your hands hovering over the keyboard when not in use.
128. We all have different sized bodies, and this includes our hands. Select a mouse or trackball that is the right size for your hand. Your hand should comfortably grasp the mouse or trackball without the fingers being either extremely flexed or extended, and the wrist should be straight when the hand is placed on the mouse or trackball. Some mice have sizing charts so you can select the proper size with minimal trial and error.
129. When selecting a trackball or mouse, avoid input devices that have sharp edges. The device should have a tear-drop shape to follow the contours of the hand, and should have a sloping or slanted surface.
130. When selecting a mouse, the mouse should be long enough that the base of the palm rests on the mouse.
131. When selecting a mouse, select a mouse that is as thin (measured from table to top of mouse) as possible.
132. When selecting a mouse, the length and curve of the mouse should result in the "peak" of the mouse (the highest point of the mouse) occurring at the large knuckle joints of the fingers (the base of the fingers).
133. Do not strike the keys on the keyboard with more force than is necessary. Many workers use more force than is required, and this has been associated with increased risk of developing upper extremity Cumulative Trauma Disorders (CTDs).
134. Workers with poor typing skills will often compensate for this by striking keys harder than required. Evaluate your typing skills and see if you could benefit from some additional formal typing skills training.
135. Remember to grasp the mouse loosely (don't squeeze the mouse), to minimize force requirements.
136. Use a light touch when you click the mouse or trackball.
137. Move the mouse using the arm muscles rather than using the wrist or hand muscles to move the mouse (in other words, let the largest muscles do the work).
138. When using the mouse, do not rest your wrist or forearm on the table.
139. When grasping the mouse, keep all of your fingers on the mouse (some people have a tendency to raise the little finger off the mouse when using it).
140. Learn what adjustment features your mouse or trackball software provides. Use the available software to get better cursor control when using the mouse or trackball. Change the acceleration control to minimize movement of the mouse relative to the cursor on the screen. Use the drag lock function of the mouse to minimize static grips on the mouse or trackball.
141. Clean the mouse on a regular basis so that the ball smoothly moves the cursor on the screen. This reduces motion requirements and saves time.