ERGONOMICS by liuqingyan

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									Photo: “Tulalip Bay” by Diane L. Wilson-Simon
    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)
INTRODUCTION
        ERGONOMICS
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”
           ERGONOMICS

Benefits of Ergonomics Include:

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


Work-Related Musculoskeletal
Disorders (WMSD) accounted for an
average total of $410.3 million of
worker’s compensation claims in the
years 1995-1997
               ERGONOMICS
 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
     State Fund Claims - Statewide 1990-98*
   Number of Claims                    Cost of Claims

                      WMSDs
           All                            All  WMSDs
                26%                     other 40%
         other
         claims                         claims
            74%                          60%


* Note: This data does not include lower extremity WMSDs.
 Source: SHARP Report No. 40-4a-2000
       ERGONOMICS


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
    805     Nursing, Personal Care Facilities                  2,177
    421     Trucking and Courier Services (non-air)            1,591
    541     Grocery Stores                                     1,486
    152     General Bldg Contractors, Residential              1,361
    174     Masonry, Tile, Plaster                               703
    836     Residential Care                                     445
    242     Sawmills, Planing Mills                              432
    175     Carpentry, Floor Work                                429
    078     Landscape, Horticultural                             420
    451     Air Transportation, Air Courier                      411
    176     Roofing, Siding, Sheet Metal                         388
    177     Concrete Work                                        287
                                Total     10,130
   These 12 SICs alone account for 20% of WMSDs
                                                       Source: SHARP Report No. 40-4a-2000
The Cost-Benefit Ratio
Is Substantial
 Statewide               Statewide
 estimated               estimated
 annual costs            annual costs
 to comply               saved by
 with the rule:          ergonomics
                         prevention

 $80                     $340
 Million                 Million
The Estimated Savings to Business
Is $4 for Every $1 Invested
REGULATIONS
        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
         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
        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))
       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”
           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
 WORK-RELATED
MUSCULOSKELETAL
   DISORDERS
          ERGONOMICS
Work-Related
Musculoskeletal
Disorders (WMSDs)
are occupational
disorders that
involve soft
tissues such as
muscles, tendons,
ligaments, joints,
blood vessels and
nerves
             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
                  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
              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
                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
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’s
      Tendonitis
    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
           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
               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
INCREASED RISK
   FACTORS
Caution
 Zone          What is a
          “Caution Zone” job?
          Look for These Indicators:

Caution
          Awkward Postures
 Zone
          High Hand Force
          Highly Repetitive Motion
          Repeated Impact
          Heavy, Frequent or Awkward
           Lifting
          Moderate to High Hand-Arm
           Vibration
  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
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 30º
For 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
            Squatting
For more than 2 hours per day
            Kneeling
For more than 2 hours per day
High Hand Force
More than 2 hours per day of:
       Pinching 2 or
       more pounds
       weight or 4 or
       more pounds
       force
High Hand Force
More than 2 hours per day of:
                Gripping 10 or
                more pounds
                weight or force
 Highly Repetitive Motion
Workers repeat same motion every
few seconds for more than 2 hours
per day with:
– neck
– shoulders
– elbows
– wrists
– hands
Highly Repetitive Motion
Intensive keying
for more than 4 hours per day
Repeated Impact
 Using hands or knees as a hammer
  – more than 10 times per hour
  – more than 2 hours per day
Repeated Impact
 Using 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 Level
    more than
    2 hours/day
Moderate to High
Hand-Arm Vibration
     High Level
     More 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 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
              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




FORCE             FREQUENCY
                      THE GOAL IS
                      TO ELIMINATE
                      AT LEAST ONE
                      FROM EVERY

        POSTURE       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
       Awkward Positions
•Knees - Squatting
    More than 4 hrs/day
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
              •Arms, Wrists, Hands
High Hand Force   –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 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
      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
   Highly Repetitive Motion
•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
Heavy, Frequent or 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
          Manual Handling
• Manual handling is      •   Lifting
  transporting or         •   Carrying
  supporting a load by    •   Putting down
  hands or bodily force
  - This includes:        •   Pushing
                          •   Pulling
                          •   Moving
                          •   Supporting
Hand-Arm Vibration
       Hand-Arm Vibration
Step 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
                                               Hand-Arm Vibration
                                      50
          Vibration value (in m/s2)
                                      40

                                      30

                                      20

                                      10

                                      0
                                           0   1   2   3     4       5   6   7   8
   Example:                                            Time (in hours)
   An impact wrench
   with a vibration value
   of 12 m/s2 is used for
   2½ hours total per
   day.


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 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
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
  General

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

Wallboard lifting system for installing drywall
      ERGONOMIC SOLUTIONS
Lift assist device to eliminate heavy, awkward
lifts in nursing homes and home health care
Repetitive Awkward   Back    Gripping
 Motion    Lifting   Angle




               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-tool

          • Reduce weight of tool

          • Rotate jobs

          • Use 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 Station




    Courtesy 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 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,
  you will always be at risk (it is a chronic
  condition)

• Tell your supervisor as soon as you
  suspect 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 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
“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 Issues
    Posture: Orientation to Work
• Elbows at 90° to
  105°
• Whenever
  possible, unload
  your upper
  extremity
              From the Top…
• Position keyboard relative to major functions
• Minimize wrist deviation
                Compression

• 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…
    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
Mouse – Common Complaints
Mouse Platform
      Mouse Platform
Notice that reaching forwards and sideways is
             substantially reduced.
   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
   Short Keyboard
A 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 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…
Lighting Options…
Proper Seating
Upper 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 Anatomy
The 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 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.
            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
     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
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 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 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
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
Q. Will wearing
a back support
belt increase my
maximum lifting
potential?

A. No. Manufacturers of back
support belts do not claim they
increase 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
 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
    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
    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 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
     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
        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
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
      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
      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       • Average Cost of
  Common WMSDs:           Common Controls:
  1. Low back: $6,000    1. Hydraulic lift: $600

                         2. Adjustable height
 2. Shoulder: $7,000        workstation: $800


 3. Elbow: $4,000        3. Powered screwdriver:
                            $100

 4. Wrist: $5,500        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

								
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