1 OFFICE ERGONOMICS ASC Command Surgeon’s Office AMSAS-SG DSN 793-2702 Work-related musculoskeletal system disorders (WMSDs), such as carpal tunnel syndrome and back pain, are the cost of not doing business right. Using proper ergonomic principles we often can prevent this. So lets begin with what is ergonomics?
2 ErgonomicsErgonomics is the study of people in relation to their work placeImproves the interaction between humans and the machines they use for workAdvantages:Reduces injuriesImproves quality of life in the workplaceImprovements are often not expensiveErgonomics is the study of people’s performance and well-being in relation to their job tasks and environment. It also seeks to improve the interaction between humans and the machines and tools they use to perform their work. Seeking the best fit between workers, their equipment, and their work environment pays off for both management and workers. Management can achieve fuller use of the work force by reducing their number of injured and light duty workers. Workers benefit through a healthier, safer work environment and thus improves their quality of work life as well as their satisfaction.
3 Purpose – Office Ergonomics What we will cover:How to setup comfortable workstation – using a step-by-step guideDetermine what office equipment is best to meet the needs of different individualsIdentify ways to reduce WMSD* riskAt the completion of this briefing you will be able to setup your workstation properly and recognize the risk factors that can lead to work-related musculoskeletal disorders in the office. In addition, you will learn ways to reduce that risk.*WMSD: work-related musculoskeletal disease
4 Office Ergonomics What’s the problem with sitting all day? Which WMSD risk factors exist in an office setting?So what is the problem with sitting all day? It seems that performing activity while sitting should allow time for rest and present very few threats to health. The reality is that there are many risk factors to which office workers are exposed that can cause health problems.
5 Office Ergonomic Risk Factors Stressors in the Office Highly repetitive motions with little recovery timeAwkward postures (hands, arms, wrists, neck, shoulder, legs)Static muscle loadingVisual/Mental demands - constant attention, stressContact stress (thighs, arms, palms)Let’s discuss the ergonomic stressors associated with computer use. Think about the physical stressors and other contributing risk factors.Steady typing involves heavy repetition with little opportunity for muscle recovery. Inadequate recovery leads to fatigue.An improperly set up workstation leads to poor postures. If these postures are sustained, there may be static muscle loading which leads to soreness, stiffness, and pain. Employees who are uncomfortable often are less productive during the workday.Computer tasks can often be visually or mentally demanding which are contributing factors. Stress and constant attention requirements are also contributing factors.A computer workstation can cause contact stress for the computer user on the thighs (from the chair), arms (from the chair or workstation edge) and palms (from the workstation or the keyboard tray).
6 Office Locations or Similar Activities How many computers do you interact with? (office, home, and travel)Like activities (i.e., video games, musical instruments, hobbies)Duration exposure today in childrenRemember that you body reacts to the sum of all of your mechanical exposures no matter where they occur. If you use a computer during your work day, you need to add in the exposures you get at home and other activities. If you engage in activities that include movement patterns that are similar to those you do in the office, these have to be figured in. For example, video game playing, musical instruments (piano/organ playing, brass and woodwind instruments, guitars), and hobbies (sewing, painting, etc) all contribute.All of these add cumulative stress to your body and everyone is different. Some handle these stressors better than others and will never have a problem while others develop musculoskeletal problems at an early age.Also, think about the fact that the span of years to which one is exposed to mechanical stresses from office-type activity is expanding. Today children are learning keyboarding in kindergarten. Video gaming also increases similar stressors. Children will be subjected to many more years of this activity than we currently are and should learn how to manage these stresses early.A good way to help minimize the stressors that lead to musculoskeletal disorders is to have a properly setup workstation at work.
7 Poor Office Ergonomics Assessment Indicators Employee is wearing wrist splintsHome-made modifications are observedMouse not on the same level as the keyboardReaching for the mouseElbow's are not at 90 degrees, wrists are deviatedEmployee is leaning forwardThe following lists indicators of poor ergonomics. Do you emulate one or more of these indicators? They include:Employee is wearing wrist splintsHome-made modifications are observedMouse not on the same level as the keyboardReaching for the mouseElbow's are not at 90 degrees, wrists are deviatedEmployee is leaning forward
8 Poor Office Ergonomics Assessment Indicators (continued) Employee looks uncomfortableEmployee’s feet are not supportedEmployee’s legs do not fit under the deskEmployee’s knees are touching the keyboard trayEmployee’s shoulders are hunched upMore indicators of poor ergonomics in the workplace:Employee looks uncomfortableEmployee’s feet are not supportedEmployee’s legs do not fit under the deskEmployee’s knees are touching the keyboard trayEmployee’s shoulders are hunched up
9 Creating the Ideal Workstation: A Step-by-Step Guide A DoD Ergonomics Working Group Plan to include:Illustrated guidelines on how to adjust workstationInformation on how to organize work area and tasksChecklists to evaluate a workstationSpecification lists when purchasing new equipmentWhen we apply ergonomic design principles to the computer work area, furniture, and equipment, visual and musculoskeletal discomfort and fatigue are reduced significantly.The DoD Ergonomics Working Group developed a guide called “ Creating the Ideal Workstation: A Step-by-Step Guide” that provides a 13-step plan to create an ergonomically sound workstation. It contains all that is needed to setup a workstation, the most important being the checklists.- Illustrated guidelines on how to adjust your workstation- Information on how to organize work area and tasks- Checklists to evaluate a workstation- Specification lists when purchasing new equipment
10 Creating the Ideal Workstation: A Step-by-Step Guide Work AreaDeskChair – seatChair – backrestFootrestMonitorKeyboardMouseOther input devicesDocument holderLightingGlareRadiationNow I am going to go through and highlight the DoD Working Group’s Step-by-Step Guide to create an ergonomically sound workstation. The 13 steps are listed here. Again, I am going to just highlight the key aspects and not all 13. It is located on two web sites that are listed at the end of this presentation if you would like to go through it yourself. Each step has a checklist that allows you to see if your workstation is setup properly.Again, this is a “Guide” and does not mean that every government workstation must meet these steps. It can be used by workers to justify and request upgrades or changes in their workstation to their supervisor. As everyone knows, resources must be available. There are many ways to adjust a workstation to make it ergonomically correct. Workers themselves can often make changes and improvements to their workstations without purchasing new workstations or equipment. The guide can also assist in identifying potential ergonomic hazards before it turns into a health problem.
11 1. The Work Area Enough space to perform all tasks Now I know that many of you in BLDG 350 have either already moved into a workstation as shown or will soon. So today I will ensure that you all know how to adjust your workstation or at least know that it can be adjusted. If you are unable make the noted adjustments please ask for assistance and do not just live with it. As I go through the steps to setup a ideal workstation for your needs I will point out various aspects of the new workstations and chairs. Much of what I discuss about the new workstations should apply to most workstations throughout JMC.It should have……Enough space to perform all tasksAllows you to place items you use most directly in front of youComfortable room temperature
12 2. The Desk Your shoulders are relaxed 75 °- 135 °Your shoulders are relaxedYour upper arms are close to your bodyThe angle between upper arm and forearm is 75° °2. The DeskFirst, the desk should be setup so that your shoulders are relaxed, your upper arms are close to your body, and the angle between your upper arms and forearms is between 75 and 135 degrees as shown.
13 2. The Desk Adjustable Surface Desktop is a matte finishAdjustable keyboard tray22” to 28” from the floorAcceptable under-desk clearance17” for knees23½” for feet20” minimum widthIdeally, your desk should have an adjustable surface large enough to accommodate a monitor, an adjustable keyboard tray and is of a matte finish to minimize glare and reflection.Adjustable desktops and keyboard trays allow for different operators and a variety of tasks to be performed. Note that your desk surfaces can be adjusted to various heights as circled. Please contact your supervisor if this is needed to fit the desk to you.
14 2. The Desk Adjustable Keyboard Tray Adjustable surfaceDesktop is a matte finishAdjustable keyboard tray22” to 28” from the floorAcceptable under-desk clearance17” for knees23½” for feet20” minimum widthThe keyboard tray should be adjustable and separate as shown in the photo. The minimum adjustment range for a keyboard tray on a sitting workstation should be 22 to 28 inches from the floor. The new workstations do meet these standards.22” to 28”
15 2. The Desk Adjustable Keyboard Tray Vertical adjustment lever Adjustable surfaceDesktop is a matte finishAdjustable keyboard tray22” to 28” from the floorAcceptable under-desk clearance17” for knees23½” for feet20” minimum widthTray angle adjustmentUnderneath the tray is the vertical adjustment lever as shown in the top photo for the new workstations. If working properly, it should allow the tray to move up or down.There is also a lever that once loosened allows for the tray angle to be adjusted and then locked into place as seen in the bottom photo.
16 2. The Desk Under-desk Clearance knees: 17”feet: 23½”20” wideAdjustable surfaceDesktop is a matte finishAdjustable keyboard tray22” to 28” from the floorAcceptable under-desk clearance17” for knees23½” for feet20” minimum widthFrom your desk’s edge, the minimum under-desk clearance depth should be 17 inches for your knees and a 23 ½ inches for your feet – meaning how far your knees and feet should extend under your desk.The minimum under-desk clearance width should be 20 inches. That is there should be 20 inches for your legs to move side-to-side.
17 3. The Chair Easily adjustable (with one hand) Controls are easily reachedSeat heightSeat pan lengthSeat pan slopeBackrestArmrestProvide immediate feedbackOperation of the controls are logical and consistent3. The ChairThe chair is the most intimate piece of equipment the office worker has, yet it is often overlooked in the design of a workstation. People vary widely in their shapes and sizes, and the chairs they use should allow for this. Thus, the chair must adjust to the size and comfort of each worker.The chair should be easily adjustable and require the use of only one hand.• The controls should be easily reached and adjusted from the standard seated work position.• The controls should provide immediate feedback.• The operation of the controls should be logical and consistent.The controls for the new chairs that I am going to discuss today are: seat height, seat pan length, seat pan slope, backrest, and armrests. Those of you who do not have these chairs yet, your controls should be fairly similar. If not, please ask for assistance.
18 Seat height adjustment 3. The Chair – SeatAdjustable deskFeet are flat on the floorBack is supportedThen adjust your deskNon-adjustable deskAdjust your chair to comfortFeet may not touch floor – then add foot restIdeal Seat heightCrease behind knee is slightly above the seatMinimum adjustment: 16” to 20½”Seat height adjustmentNow for the Seat Height of your chair.• Adjust the seat height so your feet are flat on the floor and your lower back is supported, then adjust your desk or work tray to fit you.• If your desk is not adjustable, adjust your chair to allow you to reach your work comfortably. Since you are adjusting to your desk, your feet may not touch the floor. You can support your feet by adding a footrest.• Ideally, you should adjust your seat height until the crease behind your knees is slightly above the seat. The minimum adjustment range for seat height should be 16 to 20½ inches.The control to adjust the seat height is the middle lever on the right side of the new chairs as shown in the bottom photo.
19 Seat pan length adjustment 3. The Chair – SeatSeat Pan LengthLength = 15” to 17”With your back against the seat, the front edge of seat pan should not touch the crease of kneeSeat Pan – too shortInadequate thigh supportLeads to whole body discomfortSeat Pan – too longLonger than buttock-knee length leads to leg discomfortForces you to sit forward away from the backrestSeat PanSeat pan length adjustmentNext is the seat pan (that is the part of the chair that you actually sit on).• The seat pan should be 15 to 17 inches long. With your back against the backrest, the front edge of the seat pan should not touch the crease of your knee.• A seat pan that is too short may not give adequate support under your thighs. This may force you to shift your weight to other body tissues, which leads to whole body discomfort during long periods of sitting.• If the seat pan is longer than your buttock-knee length, the front edge of the seat contacting the back of your legs can cause discomfort, and force you to sit forward in the seat, completely out of contact with the backrest.These chairs allow the backrest to move forward over the seat pan, allowing you to adjust the seat pan length. The control to adjust the seat pan length is located on the front left corner of the seat as shown in the lower photo. By pushing it down it allows you to slide the seat pan forward or backwards. Please note that if the seat back is to low it will not allow the seat pan to move and you may need to raise the seatback first.
20 Seat pan tilt adjustment 3. The Chair – SeatSeat Pan SlopeAdjustable range that allows for 5° of tilt (forward and backward)Should lock into positionSeat pan slope = 5° tiltSeat pan tilt adjustmentThe seat pan should have an adjustable range that allows 5 degrees of tilt both forward and backward. If you lean forward for a significant part of the day, a forward tilting seat pan is important. The seat pan should lock into position.The seat pan tilt control is the front right lever as shown in the lower photo. Lowering the lever allows for the tilt of the seat pan. Raising the lever then locks it back into place.
21 4. The Chair – Backrest Allows for natural body movements Contains a lumbar (lower back) supportVertical seat back adjustment (6” to 10” above seat)Surface minimum of 15” high and 12” wideContour to the curve of your lower backLarge enough to support entire backHave a forward and backward tilt (minimum of 15°)Extend high enough to support upper trunk, head, and neck when leaning backMinimum Tilt = 15°4. The Chair’s BackrestThe support surface of your backrest should be a minimum of 15 inches high and 12 inches wide, and should contour to the curve of your lower back. The backrest should also:• Be large enough to support your entire back, but should not interfere with the use of your arms.• Have a forward and backward tilt, reclining a minimum of 15 degrees and locking into place to provide support if you choose to sit back in a relaxed position.• Extend high enough to provide support to your upper trunk, head, and neck when you lean back.• Contain a spring-loaded pivoting mechanism, which allows it to follow your natural body movements while maintaining constant body support.The chair back should also have a lumbar (low back) support that conforms to your lumbar curve. If the lumbar support is permanently attached to the seat back, there should be a vertical seat back adjustment to allow you to position the middle of the lumbar support. The seatback should adjust at a minimum of 6 to 10 inches above the seat pan.
22 4. The Chair – Backrest Vertical seat back adjustment Backrest tilt adjustmentMinimum 6” to 10” above seat panVertical seat back adjustmentBackrest tilt adjustmentOn the back side and underneath the seat back is the vertical seat back adjustment lever as shown in the left photo. It allows you to raise the seat back as needed.The back rest tilt control is the rear right lever as shown in the right photo. Lowering the lever allows for the tilt of the back rest. Raising the lever then locks the seat back into place.
23 4. The Chair – Armrests Adjustable armrests Minimum of 16” apartVertically adjustable to match their height to your elbows at restArmrest height and desk or keyboard height is the sameArmrests should be:Long enough to support forearmWide enough to support forearmPadded and softRemovableMinimum of 16” apartArmrest adjustmentThe Chair Armrests• The armrests should be a minimum of 16 inches apart. Adjust the armrests so that they are close enough to your sides that you can lean on them without straining, but far enough apart to allow room for your thighs.• Armrests should also adjust vertically so you can match their height to the height of your elbow at rest. Adjust the vertical height of the armrests to allow you to easily keep your shoulders relaxed, and your upper arms close to your abdomen (the armrests should be about elbow height).• Rearrange the workstation components so the armrest height and the desk or keyboard tray height are the same.The armrests should also be:- Long enough to support your forearm (e.g., from the elbow to the base of the hand).- Wide enough to support your forearm. Avoid narrow armrests (they may dig into your arm).- Padded and soft. Avoid hard, stiff armrests.- Low and short enough to fit under the work surface. You must be able to reach the work surface and still be able to use the chair’s backrest for support.• Armrests should be removable. If you have large thighs, you may be more comfortable without armrests.The armrest adjustment lever for these chairs are located underneath each armrest. Lifting up the lever allows the armrest to move up or down.
24 5. The FootrestNeeded if your feet do not rest flat with a correctly adjusted chair. It should be:AdjustableDoes not restrict leg movementEasily removedAs wide as your hipsLarge enough for the soles of both feetHas a nonskid surface5. The Footrest.You need a footrest if your feet do not rest flat on the floor after your chair has been properly adjusted.Your footrest should be:• Adjustable in height and inclination.• Designed so it does not restrict leg movement.• Easy to remove.• As wide as your hips.• Large enough to support the soles of both of your feet.• Covered with a nonskid material to reduce slippage.Several footrest models can move while your feet are resting. The slope responds to the movement of your ankle and alters slightly in height as your foot moves. This allows some leg and foot movement that may help counteract the effects of sitting.As a quick temporary fix for a footrest, use old phone books or binders.Temporary fix: old phone books or binders
25 Top of monitor at eye height Minimum distance = 16 inches 6. The MonitorImages clear & stableBrightness & contrast controlsAdjustableTilts verticallySwivels horizontallyIf you wear bifocals, lower monitor to avoid neck tiltMonitor positionGaze slightly down to view center of screen (top of monitor at eye height)16” minimum from eyes to screenTop of monitor at eye heightMinimum distance = 16 inches6. The Monitor.The monitor should be clear and easy to read with no perceptible flicker or waiver and have brightness and contrast controls.Monitors should swivel horizontally and tilt allow you to adjust for the best viewing angle. Tilt the monitor screen slightly to accommodate your line of sight.For comfortable head and neck placement, position your monitor screen to allow you to gaze slightly down to view the center of the screen. Typically that means the top of the monitor is at eye height.- If your monitor is too low, place it on a stable box or monitor stand.- If your monitor is too high, and adjusting your desk surface and chair (and adding a footrest if necessary) doesn’t help, consider replacing it with a smaller monitor.• If you wear bifocals, you might want your monitor positioned lower.•To reduce eye strain, keep your monitor screen at least 16 inches from your eyes (or farther away than you might hold a book).Studies have concluded that user-preferred viewing distances (between your eye and the screen or source document) are normally—24 to 34 inches. Flat panel monitors can now often accommodate these preferred distances.User preferred viewing distances: 24” to 34”
26 7. The Keyboard Choose a keyboard with: Adjust keyboard height: Independent angle adjustmentA thin profile to minimize wrist extensionA matte-finished surfaceAdjust keyboard height:To reduce tension, low enough so arms are relaxed at your sidesAngle between upper arm and forearm is 75° - 135°The Keyboard.Choose a keyboard that is detached from the display screen and has:• An independent angle adjustment (typically on the bottom of keyboard as shown in the photo).• A thin profile to minimize wrist extension.• A matte-finished surface to reduce reflections and ease eye strain.
27 7. The Keyboard Choose a keyboard with: Adjust keyboard height: Independent angle adjustmentA thin profile to minimize wrist extensionA matte-finished surfaceAdjust keyboard height:To reduce tension, low enough so arms are relaxed at your sidesAngle between upper arm and forearm is 75° - 135°75 °- 135 °The height of your keyboard depends on the height of your work surface and chair. To reduce tension in your shoulder muscles, the keyboard should be low enough so your arms are relaxed at your sides. Adjust the keyboard tray so that the keyboard allows an angle between your upper arm and forearm in the range of 75o to 135o.
28 7. The Keyboard (continued) Wrists bent < 5° left or rightAdjust keyboard so that:Wrists are bent no more than 5° left or rightWrists are bent no more than 10° up or downIf keyboard is not adjustable or too low, use paper books to raise it up temporarilyIf keyboard is too high, raise your chair or place some padding under your wrists to keep them from droopingWrists bent < 10° up or downAdjust the height of your keyboard so that your wrists are bent no more than 5o to the right or left and no more than 10o up or down.• If your keyboard is not adjustable or is too low, use a pad of paper or some books to raise it up as a quick, temporary fix.• If it is too high, raise your chair or place some padding under your wrists to keep them from drooping. Your hands should be able to move easily and be in a reasonable straight line with your forearms.
29 7. The KeyboardKeep your wrist floating, but keep forearms supported on armrestsWrist and palm rests:Reminds you to keep your wrist straight or only slightly bentIntended for a wrist rest between typing, not continuallyKeep your wrists floating while you type, but support your forearms (such as with your chair armrests). Lack of forearm support creates constant shoulder and neck tension and may produce frequent headaches. Let me repeat that …… Lack of forearm support creates constant shoulder and neck tension and may produce frequent headaches.If used a wrist or palm rest should be at least as wide as the usable portions of the keyboard and should match the shape and the height of the keyboard.• A keyboard fitted with a palm rest, supports the heel of your hand and minimizes hand contact with sharp table edges.• A padded wrist rest provides either a rest for the wrist during breaks from typing, or a reminder to keep your wrist straight or only slightly bent. It is not intended to be a permanent place to rest your wrists during typing.
30 8. The Mouse Located directly in immediate reach zone Shoulders relaxed at sidePositioned as close to your body as your keyboardHoused together with your keyboard on an adjustable work surface or tray8. The Mouse.The mouse is the most popular input device and is designed to fit the contours of your hand. Place the mouse in your immediate reach zone for natural comfort and maximum hand-to-eye coordination. Placing your input device too far away, too low, or too much on one side can cause shoulder, wrist, elbow, and forearm discomfort.Since the keyboard is used with a mouse, they should be housed together on an adjustable work surface or on a large adjustable tray and not as shown in the top photo. Note how the soldier is reaching for the mouse and his right shoulder is not relaxed at his side but rather is extended. He his unable to rest his forearm on the chair armrest as shown in the bottom photo where the mouse is placed on the same tray as the keyboard. Which is a photo of your new workstations with the adjustable keyboard trays.
31 10. The Document HolderNeeded if you refer to printed materials often. It should be:StableEasily adjustable (height, position, and angle)Placed next to your screen at the same height or between your screen and keyboard10. The Document Holder.If you refer to printed materials often, keep them on a document holder adjacent to the screen. A document holder should be stable, but you should be able to adjust its height, position, distance, and angle of view.Place the document holder either next to your screen at the same height, or between your screen and keyboard. This will allow you to look from the document holder to the screen with little movement of your neck and back and prevent frequent changes of focus. However, if you need to exercise your eyes, place the document holder at a different distance from the monitor. This will help reduce eye strain by giving your eyes something different to focus on. You can also look out a window or at an object far away. This will help to rest the eyes muscles that help you focus at various distances.To exercise eyes: place holder at different distance
32 SummaryOffice ergonomic WMSD risk factors exist in the office, home office, and TDYPotential solutions involve improving posture, reducing repetition, and minimizing durationI just covered most but not all of the 13 steps to setup an ideal workstation. In summary, there are many simple and often inexpensive ways to correct a worker’s posture or workstation. It just takes the effort to make the changes. During this lecture you learned how to identify risk factors for work-related musculoskeletal disorders in the office setting. You also were provided with information that will help develop solutions to reduce work-related musculoskeletal disease risk factors.
33 Summary A good office setup/posture: Eyes are level with top of monitorNeck is not bentBack is slightly reclined/no slouchingShoulders are relaxedArms are supportedForearm, wrists, hands are straightMouse is next to the keyboardKnees are slightly higher than the hipsFeet are firmly supportedAgain, a good office setup and posture is listed here.
34 Ergonomic SitesDoD Ergonomics Working GroupUSACHPPM Ergonomics ProgramBoth sites contain:DoD Working Group’s Creating an Ideal Workstation: A Step-by-Step GuideThe Step-by-Step Guide that I used as the basis for this presentation is also located at these two sites along with other useful ergonomic information, such as point of contacts, available training, regulations, and guides.
35 Any Questions? Ergonomics POC ASC Industrial Hygienist 309-782-2702 If you have any questions about your workstation setup or other ergonomic concerns please contact MAJ Gehrels, your ergonomics POC and command IH. He will be glad to help you.Thank you and have a great day.Ergonomics POCASC Industrial HygienistDSN