Presentation is loading. Please wait.

Presentation is loading. Please wait.

Photo: “Tulalip Bay” by Diane L. Wilson-Simon. BASIC ERGONOMICS Instructor: David Ellsworth Edmonds Community College This course is being supported under.

Similar presentations

Presentation on theme: "Photo: “Tulalip Bay” by Diane L. Wilson-Simon. BASIC ERGONOMICS Instructor: David Ellsworth Edmonds Community College This course is being supported under."— Presentation transcript:

1 Photo: “Tulalip Bay” by Diane L. Wilson-Simon

2 BASIC ERGONOMICS Instructor: David Ellsworth Edmonds Community College This course is being supported under grant number SH16637SH7 from the Occupational Safety and Health Administration, U.S. Department of Labor. It does not necessarily reflect the views or policies of the U.S. Department of Labor, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. With Thanks to & Cooperation of the Tulalip Occupational Safety & Health Administration (TOSHA)


4 ERGONOMICS WHAT IS “ERGONOMICS”??” Ergos = work Nomos = laws Ergonomics = the laws of work

5 ERGONOMICS What Does Ergonomics Mean?  Designing jobs, equipment, and work tasks to fit human physical characteristics and energy limitations  It considers body dimensions, mobility, and the body’s stress behavior  “Make the work fit the person, not the person fit the work”

6 ERGONOMICS Benefits of Ergonomics Include: – safer jobs with fewer injuries – increased efficiency and productivity – improved quality and fewer errors – improved morale

7 ERGONOMICS Ergonomic Goals:  Finding ways to make strenuous, often repetitive work, less likely to cause muscle and joint injuries -- and still get the job done.  Keeping young bodies from wearing out prematurely, and mature bodies from giving out early.

8 ERGONOMICS Work-Related Musculoskeletal Disorders (WMSD) accounted for an average total of $410.3 million of worker’s compensation claims in the years

9 This type of injury affects nearly 50,000 Washington workers each year Enough People to Fill Safeco Field!! It is estimated that the actual cost including lost taxes, wages, fringe benefits, administrative costs, etc. is close to $1.5 billion per year. ERGONOMICS

10 ERGONOMICS ERGONOMICS State Fund Claims - Statewide * WMSDs All other claims 26% 74% WMSDs 40% 60% All other claims Number of ClaimsCost of Claims Source: SHARP Report No. 40-4a-2000 * Note: This data does not include lower extremity WMSDs.

11 ERGONOMICS Nationally, almost 60% of all work-related illnesses are MSDs

12 The Problem is Widespread The Top 12 Standard Industrial Classifications (SIC) SICIndustryWMSDs per year 078Landscape, Horticultural General Bldg Contractors, Residential1, Masonry, Tile, Plaster Carpentry, Floor Work Roofing, Siding, Sheet Metal Concrete Work Sawmills, Planing Mills Trucking and Courier Services (non-air)1, Air Transportation, Air Courier Grocery Stores 1, Nursing, Personal Care Facilities 2, Residential Care Total 10,130 These 12 SICs alone account for 20% of WMSDs Source: SHARP Report No. 40-4a-2000


14 The Cost-Benefit Ratio Is Substantial Statewide estimated annual costs to comply with the rule: Statewide estimated annual costs saved by ergonomics prevention $80 Million $340 Million The Estimated Savings to Business Is $4 for Every $1 Invested


16 ERGONOMICS Current Federal Law OSHA:The federal law (OSHA Ergonomics Standard) was issued on November 14, 2000 and was scheduled to be effective on January 16, 2001

17 REGULATIONS Congress utilized the little known Congressional Review Act (CRA) to pass a joint resolution of disapproval of the new OSHA Ergonomics Standard with the Senate voting 56 to 44 on March 7 and the House voting 223 to 203 on March 8, 2001 President Bush signed the joint resolution on March 20, 2001

18 REGULATIONS The effect is that the OSHA Ergonomics Standard is REPEALED – There is no Federal Law!! NOTE: OSHA still has some regulatory “bite” in this area by virtue of the infamous “General Duty Clause” (OSHA Sec. 5(a)(1))

19 REGULATIONS OSHA General Duty Clause Each employer “shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees”

20 REGULATIONS What’s Next ? Several interested parties including Labor Unions, Business and associations such as ASSE have been meeting with Secretary of Labor, Elaine Chao to formulate a new standard that will be acceptable to all stake-holders The federal ergonomics regulations are being proposed on an industry by industry basis


22 ERGONOMICS Work-Related Musculoskeletal Disorders (WMSDs) are occupational disorders that involve soft tissues such as muscles, tendons, ligaments, joints, blood vessels and nerves

23 ERGONOMICS WMSDs are: –Daily stress to anatomical structures that may occur when a person is exposed to certain high risk activities –If the accumulating stress exceeds the body’s normal recuperative ability, inflammation of the tissue can follow –Chronic inflammation may lead to the development of WMSDs –May require weeks, months or years for development - and for recovery

24 ERGONOMICS What is The Musculoskeletal System? The Musculoskeletal System includes the following: 1.Bones – The load-bearing structure of the body 2.Muscles- Tissue that contract to create movement 3.Tendons – Tissues that connect muscles to bones 4.Ligaments – Tissues that connect bones to bones 5.Cartilage – Tissue that provides cushioning and reduces friction between bones 6.Nerves – Communication system that links muscles, tendons and other tissue with the brain 7.Blood Vessels – Tubes that circulate nutrients throughout the body

25 ERGONOMICS What Are Examples of WMSDs? 1.Sprain – Overstretching or overexertion of a ligament that results in a tear or rupture of the ligament 2.Strain – Overstretching or overexertion of a muscle or tendon 3.Tendonitis – Inflammation of the tendon inside the sheath 4.Tenosynovitis – Inflammation of the sheath around the tendon 5.Carpal Tunnel Syndrome – Compression of the median nerve as it passes through the carpal tunnel in the heel of the hand

26 ERGONOMICS What are Examples of WMSDs? 6.Tennis elbow or Golfer’s elbow – Medical term is Epicondylitis – inflammation of the tendons at the elbow. 7.Trigger Finger – Common term for tendonitis or tenosynovitis that causes painful locking of the finger(s) while flexing 8.Pitcher’s Shoulder – Rotator cuff tendonitis – inflammation of one or more tendons at the shoulder 9.White Finger – Medical term is Reynaud’s Phenomenon – constriction of the blood vessels in the hands and fingers 10.Digital Neuritis – Compression of the nerves along the sides of the fingers or thumbs

27 Injury in the making...

28 Ditto...

29 Anatomy of a Tendon

30 Tendonitis Tendon function: –Transmit force from muscle to bone Micro tears of tendon occur daily Typically repair themselves With repeated loading repair is not adequate Pain / Inflammation

31 Anatomy of DeQuervain’s Tendonitis

32 What Causes DeQuervain’s? Wringing washcloths, clothes Typing on the computer keyboard Cutting with scissors Sewing or pinching Stirring food for a long period of time Opening jars

33 Carpal Tunnel

34 Best known MSD Compression of the median nerve at the wrist Tunnel made up of nine flexor tendons and one peripheral nerve Numbness and tingling on the thumb side of the hand



37 Surgical Release of Tunnel

38 Tennis Elbow Syndrome

39 Micro-tearing at the Elbow

40 Overhead Lifting

41 Anatomy of the Shoulder

42 Reynaud’s Phenomenon or “White Finger” Caused by operating vibrating machinery – especially in cold, damp weather


44 ERGONOMICS WMSDs are sometimes referred to using other unfamiliar terms such as : 1.Cumulative Trauma Disorders – CTD 2.Repetitive Trauma Disorders – RTD 3.Repetitive Strain Injuries – RSI 4.Repeated Motion Disorders – RMD 5.Overuse Syndromes

45 ERGONOMICS Signs or Symptoms of WMSDs  Painful joints  Pain in wrists, shoulders, forearms, knees, etc.  Pain, tingling or numbness in hands or feet  Fingers or toes turning white  Shooting or stabbing pains in arms or legs  Back or neck pain  Swelling or inflammation  Stiffness  Burning sensations  Weakness or clumsiness in hands; dropping things


47 Caution Zone What is a “Caution Zone” job?

48  Awkward Postures  High Hand Force  Highly Repetitive Motion  Repeated Impact  Heavy, Frequent or Awkward Lifting  Moderate to High Hand-Arm Vibration Caution Zone Look for These Indicators:

49 Awkward Postures Being in these work positions for more than 2 hours total per day – Hands above head – Elbows above shoulder – Back bent forward more than 30 degrees – Neck bent more than 30 degrees – Squatting – Kneeling

50 Working with the Hands Above Head For more than 2 hours per day

51 Working with the Elbows Above Shoulders For more than 2 hours per day

52 Neck or Back Bent Forward More than 30º For more than 2 hours per day

53 Neck or Back Bent Forward More than 30  For more than 2 hours per day

54 Neck or Back Bent Forward More than 30  For more than 2 hours per day

55 Squatting For more than 2 hours per day

56 Kneeling For more than 2 hours per day

57 High Hand Force More than 2 hours per day of: Pinching 2 or more pounds weight or 4 or more pounds force

58 High Hand Force More than 2 hours per day of: Gripping 10 or more pounds weight or force

59 Highly Repetitive Motion Workers repeat same motion every few seconds for more than 2 hours per day with: –neck –shoulders –elbows –wrists –hands

60 Highly Repetitive Motion Intensive keying for more than 4 hours per day

61 Repeated Impact Using hands or knees as a hammer – more than 10 times per hour – more than 2 hours per day

62 Repeated Impact Using hands or knees as a hammer – more than 10 times per hour – more than 2 hours per day

63 Heavy, Frequent, or Awkward Lifting Lifting objects more than: – 75 lbs. once/day – 55 lbs. more than ten times/day – 10 lbs. more than twice/minute for more than 2 hours per day – 25 lbs. above shoulders, below knees, or at arms length for more than 25 times/day

64 Heavy, Frequent, or Awkward Lifting


66 Moderate to High Hand-Arm Vibration Moderate Level more than 2 hours/day

67 Moderate to High Hand-Arm Vibration High Level More than 30 Min/day

68 If the Employer Has “Caution Zone” Jobs, They Should:  Begin an employee awareness education program  Analyze the workplace for hazards  Reduce any hazards they find

69 Ergonomics Awareness Education Should:  Show the types, symptoms and impacts of WMSDs  Show the importance of early reporting of symptoms  Provide information on all “caution zone” risk factors  Identify the hazards and measures to reduce them


71 Analyzing Caution Zone Jobs for Hazards  Use a systematic method to look at: -physical demands -layout of work area -size, shape, and weight of objects handled  The results will help to determine controls

72 Hazard Zone Risk factors become hazardous when: -there is a longer duration of exposure -there is greater intensity -there is a combination of risk factors


74 Awkward Postures Shoulders: H ands above Head Elbows above shoulders For More Than 4 hrs/day

75 Awkward Postures Shoulders Repetitive : raising >once/minute For More Than 4 hrs/day

76 Awkward Positions Neck –Bent >45° without support or ability to vary posture More than 4 hrs/day

77 Awkward Positions Back –Bent forward >30° Without support or ability to vary posture More than 4 hrs/day –Bent forward >45° Without support or ability to vary posture More than 2 hrs/day

78 Knees - Squatting More than 4 hrs/day Awkward Positions

79 Knees -k neeling More than 4 hrs/day

80 High Hand Force Arms, Wrists, Hands –Pinching unsupported object 2 or more pounds/hand Or –Pinching with force of 4 or more pounds/hand (1/2 ream of paper) + –Highly repetitive motion More than 3 hrs/day

81 High Hand Force Arms, Wrists, Hands –Pinching unsupported object 2 or more pounds/hand Or –Pinching with force of 4 or more pounds/hand (1/2 ream of paper) + –Wrists bent in flexion 30° or more, or in extension 45° or more, or in ulnar deviation 30° or more More than 3 hrs/day

82 High Hand Force Arms, Wrists, Hands –Pinching unsupported object 2 or more pounds/hand Or –Pinching with force of 4 or more pounds/hand (1/2 ream of paper) + –No other risk factors More than 4 hrs/day

83 High Hand Force Arms, Wrists, Hands –Gripping an unsupported object 10 lbs or > per hand Or –Gripping with force of 10 lbs or > per hand (clamping light duty jumper cables onto battery) + –Highly repetitive motion More than 3 hrs/day

84 High Hand Force Arms, Wrists, Hands –Gripping an unsupported object 10 lbs or > per hand Or –Gripping with force of 10 lbs or > per hand (clamping light duty jumper cables onto battery) + –Wrists bent in flexion 30° or more, or in extension 45° or more, or in ulnar deviation 30° or more More than 3 hrs/day

85 High Hand Force Arms, Wrists, Hands –Gripping an unsupported object 10 lbs or > per hand Or –Gripping with force of 10 lbs or > per hand (clamping light duty jumper cables onto battery) + –No other Risk Factors More than 4 hrs/day

86 Wrists Bent Extension Ulnar Deviation Flexion

87 Tendonitis Risk Factors Repetition Forceful exertion Awkward / sustained postures Mechanical Stress

88 Awkward / Sustained Postures Neutral posture is the goal Built-up handles Avoid wrist deviation –flexion / extension –radial/ulnar deviation

89 Mechanical Stress

90 Highly Repetitive Motion Neck, Shoulders, Elbows, Wrists, Hands –Same motion every few seconds with little variation (Except Keying) + -No Other Risk Factors More than 6 hrs/day

91 Highly Repetitive Motion Neck, Shoulders, Elbows, Wrists, Hands –Same motion every few seconds with little variation (Except Keying) + -Wrists bent in flexion 30° or more, or in extension 45° or more, or in ulnar deviation 30° or more AND High, forceful exertions with the hands More than 2 hrs/day

92 Highly Repetitive Motion Intensive Keying Awkward posture, including wrists bent in flexion 30  or more, or in extenson 45  or more, or in ulnar deviation 30° or more More than 4 hrs/day

93 Highly Repetitive Motion Intensive Keying –No Other Factors More than 7 hrs/day

94 Repeated Impact Hands –Using Hand (heel/base of palm) as a Hammer more than once per minute More than 2 hrs /day

95 Repeated Impact Knees –Using Knee as Hammer more than once per minute More than 2 hrs /day

96 Heavy, Frequent, Awkward Lifting


98 How many liftsFor how many hours per day? per minute? 1 hr. or less 1 hr. to 2 hrs. 2 hrs. or more 1 lift every 2-5 mins lift every min lifts every min lifts every min lifts every min lifts every min lifts every min Heavy, Frequent or Awkward Lifting

99 Manual Handling Manual handling is transporting or supporting a load by hands or bodily force - This includes: Lifting Carrying Putting down Pushing Pulling Moving Supporting

100 Hand-Arm Vibration

101 Step 1: Find the vibration value for the tool. (manufacturer or web site: or measure it yourself. The vibration value will be in units of meters per second squared (m/s²) - Using a hand-arm vibration graph find the point on the left side that is equal to the vibration value

102 Hand-Arm Vibration Step 2: Find out how many total hours per day the employee is using the tool and find that point on the bottom of the graph Step 3: Trace a line in from each of these two points until they cross

103 Example: An impact wrench with a vibration value of 12 m/s 2 is used for 2½ hours total per day. Hand-Arm Vibration Note: The caution limit curve (bottom) is based on an 8-hour vibration value of 2.5 m/s². The hazard limit curve (top) is based on an 8-hour vibration value of 5 m/s²

104 Hand-Arm Vibration Step 4: If that point lies in the crosshatched “Hazard” area above the upper curve, then the vibration hazard should be reduced below the hazard level or to the degree technologically and economically feasible If the point lies between the two curves in the “Caution” area, then the job remains a “Caution Job” If it falls in the “OK” area below the bottom curve, then no further steps are necessary

105 Reducing Identified Hazards Employers should reduce hazards to below hazard level, or to a degree technologically and economically feasible through: –Engineering and administrative controls (preferred) and/or –Individual work practices and PPE Employers might also consider reducing employee hours performing a particular task to lower the hazard of the job


107 Illustrations from Ergonomic Checkpoints by the International Labour Organization (ILO), and Practical Ergonomics by the UAW-GM Ergonomics Task Force

108 ERGONOMICS Ergonomic hazards are prevented primarily by the effective design of a job or job-site and the tools or equipment used in that job Based on information gathered in the work-site analysis, procedures can be established to correct or control ergonomic hazards using either engineering controls or work practice controls

109 ERGONOMICS Thoughtful arrangements reduce stress and eliminate many potential injuries and disorders associated with the overuse of muscles, with bad posture, and with repetitive motion Some jobs expose workers to excessive vibration and noise, eyestrain, repetitive motion, and heavy lifting Machines, tools, and the work environment may be poorly designed, placing stress on workers' tendons, muscles, and nerves and in addition, workplace temperature extremes may aggravate or increase stress

110 ERGONOMICS Engineering Controls Work stations should be ergonomically designed to accommodate the full range of required movements of a worker Sufficient space should be provided for the knees and feet Machine controls should be reachable and equally accessible by both right and left-handed operators Other factors to look at include hard or sharp edges, contact with thermally conducting work surfaces, proper seating, work piece orientation, and lay-out of the workstation

111 ERGONOMICS Engineering Controls Attention must be given to the selection and designs of the tools used in the workplace to prevent the tools from having a negative effect Workers should be permitted to test tools in the actual work environment before purchasing new tools A variety of tool sizes should be available with consideration to handle sizes, right and left-handed workers, weight, center of gravity, and adequacy for gloved hands Engineering adaptations may be made to tools and tool handles

112 ERGONOMICS Work Practice Controls Key elements of a good work practice program include instruction in proper work techniques, employee training and conditioning, regular monitoring, feedback, adjustments, modification, and maintenance After workers are trained in a particular work activity, such as proper lifting, they should be monitored to ensure that they continue to use the proper techniques Improper practices should be corrected to prevent injury

113 STAY FIT FOR THE JOB... “C’mon! Keep those stomachs over the handle! Let the fat do the work!… That’s it!”

114 Stretching Prepares muscles to do work Flexible muscles not easily injured Tight muscles easily injured –Morning/After Lunch –Stress –Previous strain/sprain

115 Stretching


117 90-degree" posture: Sit upright with your elbows, hips and knees bent at right angles and your feet flat on the floor or on a footrest This position is biomechanically correct, but it can fatigue your back muscles over time Fatigue can lead to slouching, even on a chair with lumbar support

118 Forward tilt posture: Raise the height of your chair's seat a few inches and tilt the front of it downward about 8 o This will open up your hip angle and allow you to support some of your weight using your legs rather than having it all rest on your hips and the backs of your thighs You may not find this posture comfortable if you have knee or foot problems, or if you feel like you are sliding off the front of the seat - A contoured chair seat can help to hold you in place

119 Reclining posture: Lean back 10 o - 20 o into the chair's backrest and put your feet out in front of you to open up the angle at your hips and knees This helps relax your back muscles and promotes blood circulation Leaning back too far however, can result in an awkward neck posture when trying to keep your head upright

120 Standing posture: Standing provides the biggest change in posture, and is a good alternative to prolonged sitting, which can aggravate low back injuries It can be fatiguing, however, so have a counter-height chair available at standing workstations, or use a height adjustable sit/stand workstation Also, prop one foot up on a low footrest occasionally to help shift your weight

121 ERGONOMIC INJURY FACTORS Lesions to tendons of the neck, back, shoulders, arms, wrists or hands Primary causes: –Repetitive movements over long periods of time –Awkward postures –Use of excessive forces

122 ERGONOMIC SOLUTIONS: POSTURE NEUTRAL & COMFORTABLE: –Wrists straight –Shoulders relaxed with elbows close to body –Head / shoulders & back in vertical alignment –Frequent breaks when bent postures can’t be avoided

123 ERGONOMIC SOLUTIONS: REPETITION Use automatic tools for repetitive tasks (screw and bolt tightening) Eliminate unnecessary tasks / movements by redesigning maintenance procedures and workstations Take short, frequent breaks Alternate tasks and processes to use different muscle groups


125 Job Enlargement Reduce Speeds Mechanical Assists / Positioning Jigs/vices to hold parts Move work to worker Voice-recognition software Macros Mini-Breaks


127 Tools: Orientation to Work Surface



130 ERGONOMIC SOLUTIONS: HIGH HAND FORCE Use clamps and fasteners Reduce weight of tool or object Redesign tool/user interface Look at Material Handling Alternatives Use Two Hands /Alternate Hands Sharp, well-maintained tools Alternate Positions/Tasks

131 Tool Handle Design

132 Shoulder harness for landscaping tool to reduce hand forces ERGONOMIC SOLUTIONS

133 ERGONOMIC SOLUTIONS: REPEATED IMPACT Use rubber mallets & padded tools Use levers Mechanical devices

134 ERGONOMIC SOLUTIONS: HEAVY, FREQUENT, AWKWARD LIFTING Reduce or Increase load weight, capacity Handholds, rigid containers Store objects 30” or more above floor Slides, gravity chutes Hoists, lifts, forklifts, Conveyors Reduce horizontal distance Handle items once Mobile racks, storage Arrange to avoid twist

135 Wallboard lifting system for installing drywall ERGONOMIC SOLUTIONS

136 Lift assist device to eliminate heavy, awkward lifts in nursing homes and home health care ERGONOMIC SOLUTIONS

137 Repetitive Motion Awkward Lifting Back Angle Gripping Smarter, Not Harder: Bend & Brace


139 Manual Handling - Work Smarter Not Harder

140 Choose the Right Tools

141 Harder, Not Smarter! Wrong Tool

142 Choose the Right Tools


144 ERGONOMIC SOLUTIONS Using a carpet stretcher to eliminate knee impacts

145 ERGONOMIC SOLUTIONS Redesign hand-toolRedesign hand-tool Reduce weight of toolReduce weight of tool Rotate jobsRotate jobs Use clamps or visesUse clamps or vises

146 ERGONOMIC SOLUTIONS: HAND TOOLS The design of grips for hand tools can be crucial: Grip shape and size appropriate to the task and user Isolate cold temperature Keep wrist and elbow in a "neutral" position Eliminate sharp edges or pressure points Use two-handed grips (where possible) Attenuate vibration

147 Redesign the Work Station Courtesy of UCDavis

148 Bring the load down or lift yourself

149 Awkward Postures



152 Awkward Postures - Improvements

153 Awkward postures - Improvements

154 HAND-ARM VIBRATIONS (HAVS) A disorder which affects the blood vessels, nerves and muscles of the hand, wrist and forearm Can be severely disabling Is better known as Vibration White Finger

155 HAND-ARM VIBRATIONS Regular Maintenance Balancers, isolators, damping material Tool Selection –low-vibration tools –Battery rather than pneumatic operated tools –High power to weight ratio –Low torque w/cutoff rather than slip-clutch –Non-slip surface –Contoured handles

156 Why talk about HAVS? 1 Million workers are exposed to high levels of vibration, of those 460,000 are estimated to be working in construction 242,000 cases of HAVS are reported every year

157 What are the Symptoms? Tingling and numbness in the fingers In the cold and wet, fingers go blue then red and are painful You can’t feel things with your fingers Pain or tingling in your forearms at night which stop you from sleeping Loss of strength in your arms and hands

158 What are the Symptoms?

159 Who is at Risk? Users of breakers and pokers, sanders and angle grinders Users of scabblers (to clean concrete) and needle guns Users of drills and jigsaws

160 Who is at Risk? Those with a disease that reduces blood flow Workers in cold and damp conditions

161 Who is at Risk? Workers using vibrating tools Workers in contact with cold tools

162 How Can I Prevent it? Ask for low vibration tools Try a different approach to your job Use the right tool for the job Keep blades and cutting edges sharp

163 How can I Prevent it? Check to ensure that the tool has been properly maintained Reduce the amount of time you use the tool Keep the handles warm

164 How can I Prevent it? Improve your blood circulation by: Keeping warm, wearing gloves etc. Giving up smoking - Smoking drastically impairs blood flow through the body Massaging and exercising fingers during work breaks

165 Prevention Low vibration tools Use the right tool for the job Tool maintenance Reduce amount of time using the tool Keep hands & handles warm New approach to your job Anti-vibration gloves

166 What Else Can I Do? Learn to Recognize the signs of HAVS Stop work and report any symptoms to your supervisor immediately Use any control measures provided, i.e. gloves etc., that your employer has provided Ask for advice from your safety department or safety rep

167 Remember Once you have had an attack of HAVS, you will always be at risk (it is a chronic condition)Once you have had an attack of HAVS, you will always be at risk (it is a chronic condition) Tell your supervisor as soon as you suspect any symptomsTell your supervisor as soon as you suspect any symptoms



170 CARPAL TUNNEL SYNDROME Occurs with repetitive motion of hands & wrists--especially with high force levels Incidence up to 15% in certain industries A “natural” keyboard and good wrist support can help most PC users avoid problems GOOD NEWS: Have dropped about 30% since which most attribute to strong workplace ergonomics programs

171 Computer Ergonomics Routine PC user defined as spending 20 hours or more per week working at a computer Studies of PC users have not shown a risk of eye damage...although fatigue very possible NIOSH studies have not indicated a radiation hazard nor pregnancy risk from PC usage Workers using bi/tri-focal glasses before beginning PC use may need special purpose glasses for computer work

172 “NATURAL” KEYBOARDS Three types: 1. Fixed split 2. Adjustable split 3. “Sculptured” Awkward wrist postures minimized with 15 to 25 horizontal degree key split AND 8 to 66 degree vertical incline



175 Key Layout Design Changes Have: - increased comfort (81% of users) –improved postures –reduced muscle activity –lowered carpal tunnel pressure in lab settings Obtained primarily to alleviate an injury

176 WRIST RESTS No medical evidence that they reduce Repetitive Strain Injuries...As they work for some, but not for others Usage Guidelines: –Buy a rest that is even with top of keyboard –Material should be “medium-soft” (foam--gel mix) so foam doesn’t break down - AVOID hard plastic types –DON’T leave wrists on rest...which compresses carpal tunnel - Palm rest instead –Changing typing habits more critical than wrist support –MOST APPROPRIATELY USED TO REST HANDS DURING PAUSE IN TYPING LEARN TO TYPE CORRECTLY WITH “FLOATING WRISTS” FIRST!!!

177 Ergonomic chairs Adjustable back height Adjustable arm rest **Chair on left NOT ergonomically designed

178 Alternative Pointing Devices Track-balls “Scrolling” Mouse

179 Other Ergonomic PC Accessories Height-adjustable articulating keyboard tray













192 Standard Layout

193 Wrist and Hand Issues

194 Posture: Orientation to Work Elbows at 90° to 105° Whenever possible, unload your upper extremity

195 From the Top… Position keyboard relative to major functions Minimize wrist deviation

196 Compression Avoid reaching up and over Consider the wrist- rest as a transitional landing pad; not as the “bus stop” for your wrists

197 Wrist Positioning for Mousing…

198 Mouse – What it Does In order to operate the mouse while typing, the operator is frequently forced to reach forward or sideways, or even both at the same time

199 Mouse – Common Complaints

200 Mouse Platform

201 Notice that reaching forwards and sideways is substantially reduced.

202 Keyboard with a Touch Pad A keyboard with a touch pad for those applications that don’t require frequent and precise placement of the cursor

203 Short Keyboard A narrower keyboard (14”) allows one to operate the mouse without side movements

204 Where Else Can You Keep the Mouse? Placing the mouse between the operator and the keyboard requires using cordless mouse

205 Proof-Reading

206 Targeting the Work Targeting of large objects can be performed at a distance > 15 inches Targeting of small objects need to be performed at 6-10 inches, ie., needle and thread

207 Targeting Your Computer…


209 Glare…

210 Lighting Options…

211 Proper Seating

212 Upper Extremity Unloading








220 MODEL COMPUTER WORKSTATION Keyboard trays WITH wrist support Split "Natural" keyboards to facilitate neutral wrist angle Fully adjustable ergonomic chair Document holder to minimize head / eye & neck movements

221 MODEL COMPUTER WORKSTATION Corner desk units to position monitor directly in front of employee Foot rest where requested Re-organization of working materials within employee arm reach Alternative pointing devices (e.g., scrolling mouse or trackball devices



224 Lifting Safely Back Injuries are the Nation’s #1 Workplace Safety Problem

225 Normal Curves of the Spine

226 Columns of Support Posterior column of support –made up of the facet column –very stable –reflects an upright posture Anterior column of support –made up of body of vertebra and the disc –less stable –reflects a flexed posture

227 The Disc & Nerve Root The disc is the shock absorber of the spine 85% water at the age of 15 25% water at the age of 75

228 A Close-up Look

229 Forward Bending Too much spinal flexion –loads the anterior column of support –places the posterior wall of the disc at risk –has the potential for nerve root compromise

230 Balance the Curves

231 Cervical Spine Anatomy

232 The Process of Degeneration

233 Weight of the Head = lbs.

234 Muscular support of the Neck

235 Up-right Neutral Posture

236 Forward Head Postures

237 Consider Elevation of Product

238 A back injury costs an average of $11,645 in medical claims and lost time wages. National Safety Council Most back injuries can be prevented


240 The Forces Involved The amount of force you place on your back in lifting may surprise you! Think of your back as a lever - with the fulcrum in the center, it only takes ten pounds of pressure to lift a ten pound object.

241 The Forces Involved If you shift the fulcrum to one side, it takes much more force to lift the same object. Your waist acts like the fulcrum in a lever system, on a 10:1 ratio Lifting a ten pound object puts 100 pounds of pressure on your lower back

242 The Forces Involved When you add in the 105 pounds of the average human upper torso, you see that lifting a ten pound object actually puts 1,150 pounds of pressure on the lower back!

243 The Forces Involved If you were 25 pounds overweight, it would add an additional 250 pounds of pressure on your back every time you bend over!

244 Common Causes of Back Injuries Anytime you find yourself doing one of these things, you should think: DANGER! My back is at risk! Try to avoid heavy lifting.. Especially repetitive lifting over a long period of time

245 Common Causes of Back Injuries Twisting at the waist while lifting or holding a heavy load... this frequently happens when using a shovel.

246 Common Causes of Back Injuries Reaching and lifting... over your head, across a table, or out the back of a truck....

247 Common Causes of Back Injuries Lifting or carrying objects with awkward or odd shapes....

248 Common Causes of Back Injuries Working in awkward, uncomfortable positions...

249 Common Causes of Back Injuries Sitting or standing too long in one position... sitting can be very hard on the lower back....

250 Common Causes of Back Injuries It is also possible to injure your back slipping on a wet floor or ice...

251 Prevent Back Injuries Avoid lifting and bending whenever you can Place objects up off the floor Raise/lower shelves. Use carts and dollies Use cranes, hoists, lift tables, and other lift- assist devices whenever you can Test the weight of an object before lifting by picking up a corner Get help if it’s too heavy for you to lift it alone

252 Prevent Back Injuries Use proper lift procedures Follow these steps when lifting...

253 STEP ONE Stand close to the load with your feet spread apart about shoulder width, with one foot slightly in front of the other for balance

254 STEP TWO Squat down bending at the knees (not your waist). Tuck your chin while keeping your back as vertical as possible

255 STEP THREE Get a firm grasp of the object before beginning the lift

256 STEP FOUR Begin slowly lifting with your LEGS by straightening them - Never twist your body during this step.

257 STEP FIVE Once the lift is complete, keep the object as close to the body as possible. As the load's center of gravity moves away from the body, there is a dramatic increase in stress to the lumbar region of the back

258 For those Awkward Moments... If you must lift or lower from a high place: 1. Stand on a platform instead of a ladder 2. Lift the load in smaller pieces if possible 3. Push the load to see how heavy and stable it is 4. Slide the load as close to yourself as possible before lifting up or down 5. Get help when needed to avoid an injury

259 From hard-to-get-at places... Get as close to the load as possible Keep back straight, stomach muscles tight Push buttocks out behind you Bend your knees Use leg, stomach, and buttock muscles to lift -- not your back

260 Team lifting All participants should be of similar height, build and gender One person should take control of the lift, command attention, inform others and co-ordinate the lift Double the people DOES NOT MEAN double the capacity

261 If one person can lift 100 pounds: How much can two people lift? Only 70 % or 140 pounds How much can three people lift? Only 50 % or 150 pounds

262 A. No. Manufacturers of back support belts do not claim they increase maximum lifting potential. Q. Will wearing a back support belt increase my maximum lifting potential?

263 Job Analysis



266 Things You Can Do Minimize problems with your back by exercises that tone the muscles in your back, hips and thighs Before beginning any exercise program, you should check with your doctor

267 Exercise! Exercise regularly, every other day Warm up slowly... A brisk walk is a good way to warm up Inhale deeply before each repetition of an exercise and exhale when performing each repetition

268 Exercises To Help Your Back Wall slides to strengthen your muscles.... Stand with your back against a wall, feet shoulder-width apart. Slide down into a crouch with knees bent to 90 degrees Count to 5 and slide back up the wall - Repeat 5 times

269 Exercises To Help Your Back Leg raises to strengthen back and hip muscles... Lie on your stomach Tighten muscles in one leg and raise leg from floor Hold for count of 10, and return leg to floor Do the same with your other leg Repeat five times with each leg

270 Exercises To Help Your Back Leg raises to strengthen back and hip muscles... Lie on back, arms at your sides Lift one leg off the floor and hold for count of ten Do the same with the other leg Repeat 5 times with each leg If this is too difficult… keep one knee bent and the foot flat on the floor while raising the other leg

271 Exercises To Help Your Back Leg raises while seated... Sit upright, legs straight and extended at an angle to floor Lift one leg waist high Slowly return to floor Do the same with the other leg Repeat 5 times with each leg

272 Exercises To Help Your Back Partial sit-up to strengthen stomach muscles.. Lie on back, knees bent and feet flat on floor Slowly raise head and shoulders off floor and reach both hands toward your knees Count to 10 Repeat 5 times

273 Exercises To Help Your Back Back leg swing to strengthen hip and back muscles.... Stand behind chair, hands on chair Lift one leg back and up, keeping the knee straight Return slowly Raise other leg and return Repeat 5 times with each leg

274 Exercises To Decrease the Strain on Your Back Lie on back, knees bent, feet flat on floor Raise knees toward chest Place hands under knees & pull knees to chest Do not raise head Do not straighten legs as you lower them Start with 5 repetitions, several times a day

275 Exercises To Decrease the Strain on Your Back Lie on stomach, hands under shoulders, elbows bent and push up Raise top half of body as high as possible Keep hips and legs on floor Hold for one or two seconds Repeat 10 times, several times a day

276 Exercises To Decrease the Strain on Your Back Stand with feet apart Place hands in small of back Keep knees straight Bend backwards at waist as far as possible and hold for one or two seconds Repeat as needed

277 A FEW SOLUTIONS... Reduce manual material handling –Pre-Plan material drops –Utilize material handling equipment –Keep materials in “neutral zone” Equipment –Use the right tool for the job –Evaluate new tools for ergonomics –Keep sharp & in good repair –Use vibration dampening tools / gloves Reduce Duration –Mini-breaks –Multi-task –Employee rotation/job share


279 Ergonomics at Work Risk of injury - Heavy liftingCart reduces risk of injury

280 Ergonomics at Work

281 Safe Lifting Up-right neutral posture Posterior column of support Stable -- less risk of injury

282 Avoid Twisting

283 Awkward Positions Adjustability Raise Worker or Raise Work Extending or Articulating Tools Tilt Tables Magnifiers Mirrors/Video for difficult access viewing Chest, Head, Arm supports Locate Objects w/in arms reach Alternate Positions/Tasks

284 It Costs Less to Be Safe Average Cost of Common WMSDs: 1. Low back: $6, Shoulder: $7, Elbow: $4, Wrist: $5,500 Average Cost of Common Controls: 1. Hydraulic lift: $ Adjustable height workstation: $ Powered screwdriver: $ Assembly work positioner: $75


286 WE ARE HERE TO SHARE IDEAS! “Okay! I’ll talk! I’ll talk…. Take two sticks of approximately equal size and weight -- rub them together at opposing angles using short, brisk strokes…”

287 START WITH A STEERING COMMITTEE Designated Safety Coordinators Field Supervision Who must be involved-- to make a positive impact in your company?

288 STEP ONE: THE “CAUTION ZONE” INVENTORY Awkward Work Postures High Hand Force Highly Repetitive Motion Repeated Impact Heavy, Frequent or Awkward lifting Moderate to High Vibration

289 STEP TWO: EMPLOYEE AWARENESS Education for affected employees Causes of musculoskeletal disorders Caution Zone Jobs of concern How to identify and prevent WMSDs Non-work related physical activities Promote physical fitness...

290 STEP THREE: ANALYSIS OF CAUTION ZONE JOBS By the steering committee? By all field employees? By selected crafts or professions? Checklists or Pocket Cards? General or Specific Performance?

291 STEP FOUR: SET REASONABLE OBJECTIVES “If we pull this off, we’ll eat like kings!”

292 STEP FIVE: GET EMPLOYEE INPUT & IDEAS Changes in tools or equipment Use of ergonomic PPE Reducing the size & weight of loads Ideas for task variety or job rotation Remember the impact of peer pressure

293 Primitive Peer Pressure

294 STEP SIX: PRIORITIZE HAZARD REDUCTION Senior management support is needed Consider cost/benefits of changes Assign trial teams and a trial schedule Reduce exposures below hazardous levels, or to the extent technologically and economically feasible

295 STEP SEVEN: COMPANY-WIDE APPLICATION Discuss experiments at safety meetings Assign new equipment or procedures Encourage continuing suggestions Keep ergonomic awareness high at safety meetings, and during new employee orientation


297 TOOLS & RESOURCES WorkSafe Institute of Washington OSHA Website Dept. of Labor & Industries The Internet – general information search Ergonomic Equipment Suppliers Training Materials & Consultants Other?

298 Discrimination & Retaliation are Illegal ! –Employees have a legal right to report injuries and raise safety and health concerns without fear of retaliation or discrimination –If an employee becomes disabled, an employer must still comply with the Americans with Disabilities Act (ADA) –For ADA information, contact the federal Department Of Labor at or the Northwest Disability Business Technical Assistance Center at HELP-ADA

Download ppt "Photo: “Tulalip Bay” by Diane L. Wilson-Simon. BASIC ERGONOMICS Instructor: David Ellsworth Edmonds Community College This course is being supported under."

Similar presentations

Ads by Google