photo: “tulalip bay” by diane l. wilson-simon. basic ergonomics instructor: david ellsworth...

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”


Benefits of Ergonomics Include:

– safer jobs with fewer injuries– increased efficiency and productivity– improved quality and fewer errors– improved morale


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.


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.


ERGONOMICSERGONOMICSState Fund Claims - Statewide 1990-98*

WMSDsAll

other claims

26%

74%

WMSDs

40%

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.


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 10,130

These 12 SICs alone account for 20% of WMSDsSource: 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


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


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))


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”


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


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


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

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


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


Neck or Back Bent Forward More than 30ºFor more than 2 hours per day

Neck or Back Bent Forward More than 30


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

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

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

handled

The 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



Or


+–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



Or


+–No other risk factors

More than 4 hrs/day


–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


Or


+–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


Or


+–No other Risk Factors

More than 4 hrs/day

Wrists Bent

Extension

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


•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


•Intensive Keying

–No Other Factors

More 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 8

Time (in hours)

Vib

rati

on

va

lue

(in

m/s

2 )

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

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 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

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 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

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

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

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

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 - 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 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

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

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 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


http://images.google.com/imgres?imgurl=http://missig.org/julian/blog/wp-content/uploads/2006/01/natural-pro.jpg&imgrefurl=http://missig.org/julian/blog/2006/01/27/natural-ergonomic-keyboard-4000/&h=300&w=400&sz=32&tbnid=lM6StbEVj7850M:&tbnh=93&tbnw=124&prev=/images%3Fq%3Dnatural%2Bkeyboard%26um%3D1&start=2&sa=X&oi=images&ct=image&cd=2

http://images.google.com/imgres?imgurl=http://missig.org/julian/blog/wp-content/uploads/2006/01/natural-4000.jpg&imgrefurl=http://missig.org/julian/blog/2006/01/27/natural-ergonomic-keyboard-4000/&h=340&w=550&sz=27&tbnid=_kMm1ZJwj6DERM:&tbnh=82&tbnw=133&prev=/images%3Fq%3Dnatural%2Bkeyboard%26um%3D1&start=3&sa=X&oi=images&ct=image&cd=3


http://www.ergoexpress.com/index.asp?PageAction=VIEWPROD&ProdID=413

http://www.ergoexpress.com/index.asp?PageAction=VIEWPROD&ProdID=202


• 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…

Glare…Glare…

Lighting Options…Lighting Options…

Proper SeatingProper Seating

Upper Extremity UnloadingUpper Extremity Unloading

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 Involved

If you were 25 pounds

overweight, it would add

an additional 250 pounds

of 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


Twisting at the

waist while

lifting or

holding a heavy

load . . . this

frequently happens

when using a shovel.


Reaching and lifting . . .

over your head, across

a table, or out the back

of a truck . . . .


Lifting or carrying

objects with awkward

or odd shapes . . . .


Working in awkward,

uncomfortable positions . . .


Sitting or standing

too long in one

position . . . sitting

can be very hard

on the lower back . . . .


It is also possible

to injure your

back slipping on

a 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 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

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 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


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


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


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



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


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


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


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


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

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

photo: “tulalip bay” by diane l. wilson-simon. basic ergonomics instructor: david ellsworth...

Documents

ergonomics slide

ergonomics wmsds

laws ergonomics

5a1 slide

morale slide

introduction slide

msds slide

recovery slide