Post on 23-May-2017
Photo: “Tulalip Bay” by Diane L. Wilson-Simon
BASIC ERGONOMICSBASIC ERGONOMICS
Instructor: David EllsworthEdmonds 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)
INTRODUCTION
ERGONOMICSERGONOMICS
WHAT IS “ERGONOMICS”??”Ergos = work
Nomos = laws
Ergonomics = the laws of work
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”
ERGONOMICSERGONOMICS
Benefits of Ergonomics Include:
– safer jobs with fewer injuries– increased efficiency and productivity– improved quality and fewer errors– improved morale
ERGONOMICSERGONOMICS
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.
ERGONOMICSERGONOMICS
Work-Related Musculoskeletal Disorders (WMSD) accounted for an average total of $410.3 million of worker’s compensation claims in the years 1995-1997
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.
ERGONOMICSERGONOMICS
ERGONOMICSERGONOMICSState Fund Claims - Statewide 1990-98*
WMSDsAll
other claims
26%
74%
WMSDs40%
60%
All other claims
Number of Claims Cost of Claims
Source: SHARP Report No. 40-4a-2000
* Note: This data does not include lower extremity WMSDs.
ERGONOMICSERGONOMICS
Nationally, almost 60% of all work-related illnesses are MSDs
The Problem is Widespread The Top 12 Standard Industrial Classifications (SIC)
SIC Industry WMSDs per year
078 Landscape, Horticultural 420
152 General Bldg Contractors, Residential 1,361174 Masonry, Tile, Plaster 703
175 Carpentry, Floor Work 429
176 Roofing, Siding, Sheet Metal 388177 Concrete Work 287
242 Sawmills, Planing Mills 432
421 Trucking and Courier Services (non-air) 1,591
451 Air Transportation, Air Courier 411
541 Grocery Stores 1,486
805 Nursing, Personal Care Facilities 2,177
445836 Residential Care
Total 10,130These 12 SICs alone account for 20% of WMSDs
Source: SHARP Report No. 40-4a-2000
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
REGULATIONS
ERGONOMICSERGONOMICS
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
REGULATIONSREGULATIONS
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
REGULATIONSREGULATIONS
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))
REGULATIONSREGULATIONS
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”
REGULATIONSREGULATIONS
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
WORK-RELATED MUSCULOSKELETAL
DISORDERS
ERGONOMICSERGONOMICSWork-Related Musculoskeletal Disorders (WMSDs) are occupational disorders that involve soft tissues such as muscles, tendons, ligaments, joints, blood vessels and nerves
ERGONOMICSERGONOMICSWMSDs 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
ERGONOMICSERGONOMICSWhat is The Musculoskeletal System?
The Musculoskeletal System includes the following:
1. Bones – The load-bearing structure of the body2. Muscles- Tissue that contract to create movement3. Tendons – Tissues that connect muscles to bones4. Ligaments – Tissues that connect bones to bones5. Cartilage – Tissue that provides cushioning and reduces friction
between bones6. Nerves – Communication system that links muscles, tendons and other
tissue with the brain7. Blood Vessels – Tubes that circulate nutrients throughout the body
ERGONOMICSERGONOMICSWhat 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
ERGONOMICSERGONOMICSWhat 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
Injury in the making...
Ditto...
Anatomy of a Tendon
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
Anatomy of DeQuervain’sTendonitis
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
Carpal Tunnel
Carpal Tunnel• 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
Surgical Release of Tunnel
Tennis Elbow Syndrome
Micro-tearing at the Elbow
Overhead Lifting
Anatomy of the Shoulder
Reynaud’s Phenomenon or “White Finger”
• Caused by operating vibrating machinery – especially in cold, damp weather
ERGONOMICSERGONOMICS
WMSDs are sometimes referred to using other unfamiliar terms such as :
1. Cumulative Trauma Disorders – CTD2. Repetitive Trauma Disorders – RTD3. Repetitive Strain Injuries – RSI4. Repeated Motion Disorders – RMD5. Overuse Syndromes
ERGONOMICSERGONOMICSSigns 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
INCREASED RISK FACTORS
CautionZone What is aWhat is a
““Caution Zone” Caution Zone” jobjob??
Awkward Postures High Hand Force Highly Repetitive Motion Repeated Impact Heavy, Frequent or Awkward
Lifting Moderate to High Hand-Arm
Vibration
CautionZone
Look for These Look for These Indicators:Indicators:
Awkward PosturesBeing 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
Working with the Hands Above Head
For more than 2 hours per day
Working with the Elbows Above Shoulders
For more than 2 hours per day
Neck or Back Bent Forward More than 30ºFor more than 2 hours per day
Neck or Back Bent Forward More than 30
For more than 2 hours per day
Neck or Back Bent Forward More than 30
For more than 2 hours per day
SquattingFor more than 2 hours per day
KneelingFor more than 2 hours per day
High Hand ForceMore than 2 hours per day of:
Pinching 2 or more pounds weight or 4 or more pounds force
High Hand ForceMore than 2 hours per day of:
Gripping 10 or more pounds weight or force
Highly Repetitive MotionWorkers repeat same motion every few seconds for more than 2 hours per day with:– neck– shoulders– elbows– wrists– hands
Highly Repetitive MotionIntensive keying for more than 4 hours per day
Repeated ImpactUsing hands or knees as a hammer– more than 10 times per hour– more than 2 hours per day
Repeated ImpactUsing hands or knees as a hammer– more than 10 times per hour– more than 2 hours per day
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
Heavy, Frequent, or Awkward Lifting
Heavy, Frequent, or Awkward Lifting
Moderate to High Hand-Arm Vibration
Moderate Levelmore than 2 hours/day
Moderate to High Hand-Arm Vibration
High LevelMore than 30 Min/day
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
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
Analyzing Caution Zone Jobs for HazardsUse a systematic method to
look at:-physical demands-layout of work area-size, shape, and weight of objects
handledThe results will help to
determine controls
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
The ERGONOMIC TRIANGLE
FREQUENCYFORCE
POSTURE
THE GOAL IS
TO ELIMINATE
AT LEAST ONE
FROM EVERY
TASK
Awkward Postures•Shoulders: Hands above Head
Elbows above shoulders
For More Than 4 hrs/day
Awkward Postures•Shoulders Repetitive : raising >once/minute
For More Than 4 hrs/day
Awkward Positions•Neck
–Bent >45° without support or ability to vary posture
More than 4 hrs/day
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
•Knees - Squatting
More than 4 hrs/day
Awkward Positions
Awkward Positions•Knees -kneeling
More than 4 hrs/day
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
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
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
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
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
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
Wrists BentExtension
Ulnar Deviation
Flexion
Tendonitis Risk Factors
• Repetition• Forceful exertion• Awkward / sustained
postures• Mechanical Stress
Awkward / Sustained Postures
• Neutral posture is the goal
• Built-up handles• Avoid wrist deviation
– flexion / extension– radial/ulnar deviation
Mechanical Stress
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
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
Highly Repetitive Motion•Intensive KeyingAwkward 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
Highly Repetitive Motion•Intensive Keying
–No Other FactorsMore than 7 hrs/day
Repeated Impact
•Hands–Using Hand (heel/base of palm) as a Hammer more than once per minute
More than 2 hrs /day
Repeated Impact
•Knees–Using Knee as Hammer more than once per minute
More than 2 hrs /day
Heavy, Frequent, Awkward
Lifting
How many lifts For 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. 1.0 0.95 0.85
1 lift every min. 0.95 0.9 0.75
2-3 lifts every min. 0.9 0.85 0.65
4-5 lifts every min. 0.85 0.7 0.45
6-7 lifts every min. 0.75 0.5 0.25
8-9 lifts every min. 0.6 0.35 0.15
10+ lifts every min. 0.3 0.2 0.0
Heavy, Frequent or Awkward Lifting
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
Hand-Arm Vibration
Hand-Arm VibrationStep 1: Find the vibration value for the tool.
(manufacturer or web site: http://umetech.niwl.se/vibration/HAVHome.html 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
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
0
10
20
30
40
50
0 1 2 3 4 5 6 7 8Time (in hours)
Vibr
atio
n va
lue
(in m
/s2 )
Example: An impact wrench with a vibration value of 12 m/s2 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
Hand-Arm VibrationStep 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
Reducing Identified HazardsEmployers 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
ERGONOMIC SOLUTIONS
General
Illustrations from Ergonomic Checkpoints by the International Labour Organization (ILO), and Practical Ergonomics by the UAW-GM Ergonomics Task Force
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
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
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
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
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
STAY FIT FOR THE JOB...
“C’mon! Keep those stomachs over the handle! Let the fat do the work!… That’s it!”
Stretching• Prepares muscles to do
work• Flexible muscles not
easily injured• Tight muscles easily
injured– Morning/After Lunch– Stress– Previous strain/sprain
Stretching
Stretching
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
Forward tilt posture: Raise the height of your chair's seat a few inches and tilt the front of it downward about 8o 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 thighsYou 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
Reclining posture: Lean back 10o - 20o into the chair's backrest and put your feet out in front of you to open up the angle at your hips and kneesThis 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
Standing posture: Standing provides the biggest change in posture, and is a good alternative to prolonged sitting, which can aggravate low back injuriesIt can be fatiguing, however, so have a counter-height chair available at standing workstations, or use a height adjustable sit/stand workstationAlso, prop one foot up on a low footrest occasionally to help shift your weight
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
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
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
ERGONOMIC SOLUTIONS: HIGH REPETITION
ERGONOMIC SOLUTIONS: HIGH REPETITION
• Job Enlargement• Reduce Speeds• Mechanical Assists / Positioning• Jigs/vices to hold parts• Move work to worker• Voice-recognition software• Macros• Mini-Breaks
ERGONOMIC SOLUTIONS: PROPER ALIGNMENT
Tools: Orientation to Work Surface
Tools: Orientation to Work Surface
JOB ANALYSIS
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
Tool Handle Design
Shoulder harness for landscaping tool to reduce hand forces
ERGONOMIC SOLUTIONS
ERGONOMIC SOLUTIONS: REPEATED IMPACT
• Use rubber mallets & padded tools• Use levers • Mechanical devices
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
Wallboard lifting system for installing drywall
ERGONOMIC SOLUTIONS
Lift assist device to eliminate heavy, awkward lifts in nursing homes and home health care
ERGONOMIC SOLUTIONS
Repetitive Motion
Awkward Lifting
Back Angle
Gripping
Smarter, Not Harder:
Bend & Brace
JOB ANALYSIS
Manual Handling - Work Smarter Not Harder
Choose the Right Tools
Harder, Not Smarter!Wrong Tool
Choose the Right Tools
Choose the Right Tools
ERGONOMIC SOLUTIONS
Using a carpet stretcher to eliminate knee impacts
ERGONOMIC SOLUTIONS
• Redesign hand-toolRedesign hand-tool
• Reduce weight of toolReduce weight of tool
• Rotate jobsRotate jobs
• Use clamps or visesUse clamps or vises
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
Redesign the Work StationRedesign the Work Station
Courtesy of UCDavisCourtesy of UCDavis
Bring the load down or lift yourself
Awkward Postures
Awkward Postures
Awkward Postures
Awkward Postures - Improvements
Awkward postures - Improvements
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
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
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
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
What are the Symptoms?
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
Who is at Risk?
• Those with a disease that reduces blood flow
• Workers in cold and damp conditions
Who is at Risk?
Workers using vibrating tools
Workers in contact with cold tools
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
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
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
Prevention
Low vibration toolsUse the right tool for the job Tool maintenanceReduce amount of time using the toolKeep hands & handles warm New approach to your jobAnti-vibration gloves
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
Remember
• Once you have had an attack of HAVS, Once you have had an attack of HAVS, you will always be at risk (it is a chronic you will always be at risk (it is a chronic condition)condition)
• Tell your supervisor as soon as you Tell your supervisor as soon as you suspect any symptomssuspect any symptoms
JOB ANALYSIS
JOB ANALYSIS
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
1990--which most attribute to strong workplace ergonomics programs
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
“NATURAL” KEYBOARDS• Three types:
1. Fixed split2. Adjustable split 3. “Sculptured”
• Awkward wrist postures minimized with 15 to 25 horizontal degree key split AND 8 to 66 degree vertical incline
“NATURAL” KEYBOARDS
“NATURAL” KEYBOARDS
“NATURAL” KEYBOARDS
• 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
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!!!
Ergonomic chairs
• Adjustable back height• Adjustable arm rest• **Chair on left NOT
ergonomically designed
Alternative Pointing Devices
• Track-balls• “Scrolling” Mouse
Other Ergonomic PC Accessories
• Height-adjustable articulating keyboard tray
Standard Layout
Wrist and Hand IssuesWrist and Hand Issues
Posture: Orientation to WorkPosture: Orientation to Work
• Elbows at 90° to 105°
• Whenever possible, unload your upper extremity
From the Top…From the Top…• Position keyboard relative to major functions• Minimize wrist deviation
CompressionCompression
• Avoid reaching up and over
• Consider the wrist-rest as a transitional landing pad; not as the “bus stop” for your wrists
Wrist Positioning for Mousing…Wrist Positioning for Mousing…
Mouse – What it DoesIn order to operate the mouse while typing, the operator is frequently forced to reach forward or sideways, or even both at the same time
Mouse – Common Complaints
Mouse Platform
Mouse PlatformNotice that reaching forwards and sideways is
substantially reduced.
Keyboard with a Touch PadA keyboard with a touch pad for those applications that don’t require frequent and precise placement of the cursor
Short KeyboardA narrower keyboard (14”) allows one to operate the mouse without side movements
Where Else Can You Keep the Mouse?Placing the mouse between the operator and the
keyboard requires using cordless mouse
Proof-Reading
Targeting the WorkTargeting 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
Targeting Your Computer…Targeting Your Computer…
Targeting Your Computer…Targeting Your Computer…
Glare…Glare…
Lighting Options…Lighting Options…
Proper SeatingProper Seating
Upper Extremity UnloadingUpper Extremity Unloading
JOB ANALYSIS
JOB ANALYSIS
JOB ANALYSIS
JOB ANALYSIS
JOB ANALYSIS
JOB ANALYSIS
JOB ANALYSIS
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
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
BACK SAFETY & LIFTING
Lifting Safely
Back Injuries are the Nation’s
#1
Workplace Safety Problem
Normal Curves of the Spine
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
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
A Close-up Look
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
Balance the Curves
Cervical Spine AnatomyCervical Spine Anatomy
The Process of DegenerationThe Process of Degeneration
Weight of the Head = 10-12 lbs.
Muscular support of the Neck
Up-right Neutral Posture
Forward Head Postures
Consider Elevation of Product
• 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
The Forces InvolvedThe 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.
The Forces InvolvedIf 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
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!
The Forces InvolvedIf you were 25 poundsoverweight, it would addan additional 250 poundsof pressure on your back every time you bend over!
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
Common Causes of Back Injuries
Twisting at the waist while lifting or holding a heavy load . . . this frequently happens when using a shovel.
Common Causes of Back Injuries
Reaching and lifting . . . over your head, across a table, or out the back of a truck . . . .
Common Causes of Back Injuries
Lifting or carrying objects with awkward or odd shapes . . . .
Common Causes of Back Injuries
Working in awkward, uncomfortable positions . . .
Common Causes of Back Injuries
Sitting or standing too long in one position . . . sitting can be very hard on the lower back . . . .
Common Causes of Back Injuries
It is also possibleto injure your back slipping ona wet floor or ice . . .
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
Prevent Back Injuries
• Use proper lift procedures
• Follow these steps when lifting . . .
STEP ONEStand close to the load with your feet spread apart about shoulder width, with one foot slightly in front of the other for balance
STEP TWO
Squat down bending at the knees (not your waist). Tuck your chin while keeping your back as vertical as possible
STEP THREE
Get a firm grasp of the object before beginning the lift
STEP FOUR
Begin slowly lifting with your LEGS by straightening them - Never twist your body during this step.
STEP FIVEOnce 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
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
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
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
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
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?
Job Analysis
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
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
Exercises To Help Your BackWall 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
Exercises To Help Your BackLeg 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
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 legIf this is too difficult… keepone knee bent and the foot flat on the floor while raising the other leg
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
Exercises To Help Your BackPartial 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 10Repeat 5 times
Exercises To Help Your BackBack leg swing to strengthen
hip and back muscles . . . .Stand behind chair, hands on chairLift one leg back and up, keepingthe knee straightReturn slowlyRaise other leg and returnRepeat 5 times with each leg
Exercises To Decrease the Strain on Your Back
Lie on back, knees bent, feet flat on floorRaise knees toward chestPlace hands under knees & pullknees to chestDo not raise headDo not straighten legs as you lower themStart with 5 repetitions, several times a day
Exercises To Decrease the Strain on Your Back
Lie on stomach, hands under shoulders, elbowsbent and push upRaise top half of bodyas high as possibleKeep hips and legs onfloor Hold for one or two secondsRepeat 10 times, several times a day
Exercises To Decrease the Strain on Your Back
Stand with feet apartPlace hands in small of backKeep knees straightBend backwards at waist as far aspossible and hold for one or two secondsRepeat as needed
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
PRODUCTS
SCISSORS LIFT TABLE 550 LB
Ergonomics at Work
Risk of injury - Heavy lifting Cart reduces risk of injury
Ergonomics at Work
Safe Lifting
• Up-right neutral posture
• Posterior column of support
• Stable -- less risk of injury
Avoid Twisting
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
It Costs Less to Be Safe
• Average Cost of Common WMSDs:1. Low back: $6,000
2. Shoulder: $7,000
3. Elbow: $4,000
4. Wrist: $5,500
• Average Cost of Common Controls:1. Hydraulic lift: $600
2. Adjustable height workstation: $800
3. Powered screwdriver: $100
4. Assembly work positioner: $75
CREATING A COMPANY ERGONOMICS PROGRAM
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…”
START WITH A STEERING COMMITTEE
• Designated Safety Coordinators• Field Supervision• Who must be involved-- to make a
positive impact in your company?
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
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...
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?
STEP FOUR: SET REASONABLE OBJECTIVES
“If we pull this off, we’ll eat like kings!”
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
Primitive Peer Pressure
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
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
WHAT ARE OTHER COMPANIES DOING?
TOOLS & RESOURCES• WorkSafe Institute of Washington• OSHA Website• Dept. of Labor & Industries• The Internet – general information
search• Ergonomic Equipment Suppliers• Training Materials & Consultants• Other?
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 1-800-949-4232 or the Northwest Disability Business Technical Assistance Center at 1-800-HELP-ADA