2 Understanding Musculoskeletal Injury (MSI) Repetitive Motion Injuries / Repetitive Strain InjuriesCarpal tunnel syndrome is a major cause of hand discomfort but is not the only source of the problem. Often pain, numbness, tingling and weakness can be caused by other factors.Repetitive motion injuries refers to a range conditions that result from performing the same physical motion over and over again – for weeks, months, or years. Over time, this constant motion may cause temporary or permanent damage to cartilage, tendons, ligaments, nerves, and muscles involved in producing the motion.Not only do these injuries occur on-the-job, but also what you do at home can cause repetative motion injuries. Examples are: knitting, woodworking, crafts, etc.
3 Understanding Musculoskeletal Injury (MSI) MSI = injury or disorder of the muscles, tendons, ligaments, joints, nerves, blood vessels, or related soft tissue, including sprains, strains, or inflammation that may be caused or aggravated by work.Ergonomic hazards cause many types of injuries. These injuries are commonly referred to by these terms:REPETITIVE STRAIN INJURIES - RSIs, or CUMULATIVE TRAUMA DISORDERS - CTDs, or MUSCULOSKELETAL DISORDERS - MSDs.orMUSCULOSKELETAL INJURY - MSIsWork related MSIs can make normal work routines uncomfortable and even painful. This can lead to stress or dissatisfaction at work, reduced productivity, or the inability to perform some or all work activities.Tendons (connect muscles to bones)Tendonitis (swelling of the tendon)Tenosynovitis (swelling of the sheath that covers the tendon)Ganglion Cyst (accumulation of fluid within the tendon sheath)Nerves transfer information from the senses to the brain and back (swelling of the tendons can put pressure on the nerves)Carpal Tunnel Syndrome (swelling of the flexor tendons near the wrist, impairing the median nerve)Cubital Tunnel Syndrome (impaired ulnar nerve) can be caused by resting the elbows on hard surfacesThoracic outlet syndrome (compressing of the nerves and blood vessels between the neck and shoulders). Work activities involving prolonged restricted postures such as carrying heavy shoulder loads, pulling shoulders back and down, or reaching above shoulder level can cause the inflammation and swelling of tendons and muscles in the shoulders and upper arms. When swollen or inflamed, they can compress the nerves and blood vessels between the neck and shoulders.
4 MSI Risk Factors Forceful Exertion Repetitive Motion Awkward Postures Physical effort that places a high load on the muscles, tendons, ligaments, and jointsRepetitive MotionTasks that use the same muscle groups repeatedlyAwkward PosturesWorking out of the “neutral” body positionStatic PosturesBody positions held without movement for more than 20 secondsContact StressWhen body parts come into contact with hard or sharp objects
5 Poor positioning can contribute to : Workstation SetupPoor positioning can contribute to :EyestrainNeck painShoulder painThe main complaint is pain in the neck and shoulder region. This is due to reaching forwards and sideways.Repetitive movements are not so much to blame; rather it is the effort of holding one's arm with little or no support, often in an unnatural position, for a long time.Therefore our focus must be on eliminating or at least reducing the need to place one's forearm and hand to the side of the keyboard.NOTE: Think about these postures as you go through the slides. Not only are there good tips for “workstations” but also while doing most anything – whether it’s watching TV, doing crafts (such as sewing, knitting, woodworking), reading, or even driving, etc.Wrist painElbow painCramped fingersLower back painListen to your body
6 Symptoms of MSI Pain Cramping or spasm Heat or Burning Tenderness Tingling,pins and needlesor numbnessTendernessHeat orBurningPainOn which part of the body do the majority of repetitive motion injuries occur? It's all in the wrist. Source: Bureau of Labor Statistics, 2002, Occupational Injuries and Illnesses in the United States.Head, neck, trunk, including back, and shoulder = 16%Wrist = 53%Hand, finger, and other upper extremities (excluding wrist) = 23%Knee, foot, toe and other lower extremities = 2%Multiple and other = 6%Symptoms:fatigue in muscles and jointsaches and painsswelling tightness/stiffness (especially over joint areas)tingling or numbness weaknessIf you notice these symptoms occurring intermittently, you should consider the possible causes and make changes in your use of repetitive motion in performing activities. If symptoms become persistent or cause you to wake up in the night, you should seek medical help.
7 Workstation SetupMaine law states that if you work on a VDT for more than 4 hours a day, your employer must:train you to use your VDT and to avoid or minimize conditions that may arise from long or improper usetrain you on the importance of proper posture when you use a VDT and how to adjust your workstation to achieve proper posture.train you within the first month of your being hired and annually thereafter
8 Body PositionHead is level, or bent slightly forward, forward facing, and balanced.Shoulders are relaxed and upper arms hang normally at the side of the body.Elbows stay in close to the body and are bent between 90 and 120 degrees.We vary in height, in quality of sight, in physical strength, in tolerance levels and in preference to left or right handedness. Some of these differences will change substantially with age.A working position that causes no discomfort for one individual, may seriously limit the productivity of another, even if they're similar in height. This situation is more likely to exist where there is a difference in age. You’ll hear the phrase “neutral body position” quite often through this session.Hands, wrists, and forearms are straight, in-line and roughly parallel to the floor
9 Body PositionBack is fully supported with appropriate lumbar support when sitting vertical or leaning back slightlyThighs and hips are supported by a well-padded seat and generally parallel to the floorKnees are about the same height as the hips with the feet slightly forward.Feet are fully supported by floor or footrest.
10 MonitorsMonitors should be placed directly in front (but not more than 35°) to the left or rightThe screen should be at least 20” away from your eyes and at right angles to window(s) to avoid glareThe best distance is as far away as possible while still being able to read it clearly.
11 MonitorsKeep the top line of the screen at eye level or slightly below to avoid neck strainUse document holdersMake sure that the document holder fits the type of work that you will be reading from. For instance, if you have to read from a book or magazine, choose a document holder that will accommodate them. Some people use cookbook rests for books.
12 Keyboard and MouseYour wrists should be supported and in-line with your forearmsKeep the mouse close to the keyboardWrist restsAre only used to support the palms in between keying movementsShould be fairly soft and should not be any higher than the front edge of your keyboardShould encourage neutral wrist postureYour wrists should not be deviated while typingIf you use a wrist pad, make sure it’s not too high. Those gel pads are nice because they don’t cause pressure points. Your hands and wrists should be kept in a straight wrist posture when typing and should not be resting on a palm rest, table or lap while typing.Wrist and palm rests are designed to provide support during breaks from typing.
13 ChairsSeat height should be adjustable to allow your feet to rest flat on the floor (preferred) or on a footrestBackrest should provide lower back supportArmrest should be adjusted so they support your lower arm and allow your upper arm to remain close to the torsoTry out a chair – available at Central Supply/PurchasingIf your chair doesn’t have a lumbar support, you can use a rolled up towel or small pillow to support the hollow of your back.
14 WorkstationAll other equipment (mouse, telephone, copy holder, etc.) should be positioned to prevent strain and discomfort from excessive reaching, bending and turning.
15 Telephones can be a Pain in the Neck Location / awkward reachPhone neck - gripping the telephone between shoulder and headPosture – leaning forward away from the back of the chair while taking a callCell phones – awkward posture, finger and thumb strain from excessive text keyingLocation – in relation to your work area. Do you have to reach to answer it?Text messaging can cause repetitive motion injuries to the thumb. Consider an alternative to text messaging.To help prevent “phone neck” the best solution is to use a headset, or your speaker phone. If you can't use a headset, consider alternating ears for each conversation (or every ten minutes for long conversations). Changing sides (and hands) will distribute the stress more evenly, and give each ear a chance to rest. Put commonly-dialed numbers into your phone's memory. Dialing becomes more difficult on the smaller keys of a phone, meaning that there's more potential for stress and strain on your fingers. With the advent of text messaging, our fingers (and especially thumbs) are getting even more of a workout. Physicians are already beginning to see injuries associated with repeated keying, and the introduction of cell-based games has only increased the potential for problems. Finally, remember that the best solution is to limit your exposure entirely; reducing the amount of time you spend on the phone or combining phone use with alternatives like can help prevent problems from ever starting.
16 Laptops... So What’s Wrong with Them? Portability vs. ergonomicsScreens smallerScreen not independent of the keyboardSmaller keyboard, smaller keysDifferent key spacing and travelMouse is awkwardUncomfortable neck or wrist positionFurniture in hotel rooms, other offices, or home sometimes inadequate for laptop useDifficult to transportLaptops were designed with PORTABILITY in mind... Not ERGONOMICS.
17 Laptop PostureSometimes a tradeoff between neck/head posture and hand/wrist postureOccasional UserPosition laptop in your lap for the most neutral wrist postureAngle the screen so that you can see it with the “least” amount of neck deviationOf course, the normal rules of desktop computing still apply. But using a laptop sometime means that you have to tradeoff between neck/head posture and hand/wrist posture. If you can’t adjust your work area to an optimum position, here are some suggestions:Because of the large neck muscles, if you’re an occasional user, concentrate on the wrist posture. Angle the screen so that you can see it with the “least” amount of neck deviation. You can’t eliminate bending of the neck at this angle, but try for the best position you can. Don’t forget to take frequent breaks.
18 Laptop Posture Full Time User Position the laptop so that you can see the screen without bending the neckUse a separate keyboard and mouseUse the keyboard in a negative tilt to ensure a neutral wrist postureIf you’re a full time user of laptops, you should follow the basic ergonomic principals.We’ll go over some solutions on how you can achieve these on the next few slides.
19 Laptops... Suggestions Use external devices Keyboard and mouseUse commercially available laptop holders or laptop supportsOf course, the normal rules of desktop computing still apply. Try to keep your wrists in a neutral position (not bent), sit about arm's length from the screen, keep open angles with your elbows (90 degrees or greater), and use a light touch while typing.External Keyboards allow you to more freely position your keyboard, meaning that you can independently adjust both the screen and the keys to obtain a better ergonomic position. An External Mouse is often used by people who find the laptop's built-in touchpad or trackball difficult to negotiate or uncomfortable.Laptop Stands resemble a music stand; laptops are placed on a height-adjustable platform which allows a wider variety of adjustment. In essence, it's a portable desk - meaning you're not confined to the height of whatever desks or countertops happen to be convenient. Laptop stands are great for people who have a favorite chair from which they work; it lets them bring the desk to them.
20 Mobile Work LayoutMake smart choices when working in alternative settings such as coffee shops, restaurants, meeting rooms, hotels, and airplanes. Although you may not have much control over the environment, you can control how you choose to work within it.
21 Mobile Work Layout Hotel/Conference Room/Café/etc. Use a pillow, pad, folded towels, or a blanket to raise your seat heightSupport your back (lumbar region) using a rolled up towel, clothing, pillow, etc.Try using a chair without armrests to give you more room to move your armsUsing your lap is an option – look down at the screen by tucking your chin instead of bending your entire neck down
22 Breaks Operator should take regular breaks Vision and stretch breaks after 1 hour’s use of a desktopVision and stretch breaks after 1/2 hour’s use of a laptopMicro breaks (30 seconds, every 10 minutes)Breaks can consist of performing other work tasks.When you perform other work tasks, try to do some that don’t involve the same motions as computer use.
23 What Can You Take Away From This Training? Prevention is the most important strategyDon’t wait to feel pain to start changing your habitsListen to your bodyYou DON’T have to be in pain to get your job doneThere are numerous ergonomic solutions to help keep you pain freeWe’re always here to help
24 Don’t forget to document your training. Thank YouDon’t forget to document your training.A certificate of training is available on the VDT Training web page at: