Musculoskeletal
Disorders to the
Back
Recognition and Control
Manual Materials Handling
Lifting/Lowering
Pushing/Pulling
Carrying
Weights and Forces
Frequency of activities
Load Center of Gravity
Work Related Low Back Pain (LBP)



Overexertion was claimed as the cause of LBP by over 60% of LBP
patients
Two Thirds of Overexertion claims involved lifting
One fifth of Overexertion claims involved pushing or pulling loads
MSD Injuries from Lifting
30% of
Shoulder
WMSDs
43% of
Back
WMSDs
22% of
Elbow
WMSDs
13% of
Hand/Wrist
WMSDs
Source: SHARP technical report No. 40-6-2002
Evidence for Causal Relationship
Between Physical Work Factors
and Back-Related MSDs
Strong Evidence
Evidence
Insufficient Evidence
Risk Factor
Lifting/Forceful Movement
X
Awkward Posture
X
Heavy Physical Work
X
Whole Body Vibration
Static Work Posture
X
X
Common Risk Factors for Back
MSDs
• Force
• Frequency
• Posture
• Duration
• Environment
• Vibration
Back Injury Risk Factor Examples
Awkward Postures
o
o
o
o
Bending
Twisting
Reaching, etc.
Back Injury Risk Factor Examples
o
Lifting/Forceful Movements
o
o
o
o
o
Weight of load
Location (position of load w.r.t. worker)
Frequency
Stability
Coupling
Back Injury Risk Factor Examples
High Frequency and
Lifting Overhead
9
Back Injury Risk Factor Examples
Lifting or Lowering Floor Level
Lifting above Shoulder Height
Look for Clues – Use Assessment
Tools
o
Sample Checklists
o
o
General Checklists
o
Kodak Ergonomics Checklist
for Material Handling
o
NIOSH Manual Material
Handling Checklist
Risk Factor Checklists
o
Hazard Evaluation Checklist
for Lifting, Carrying, Pushing
or Pulling (T.R. Waters)
o
Washington Awkward
Postures Checklist
o
REBA – Trunk/Legs
o
Analysis Tools
o
Websites
Look for Clues – General Checklists
Kodak’s Ergonomic Checklist for Material Handling
Source: Kodak’s Ergonomic Design for People at Work, as adapted in
NIOSH 2007-131
Kodak’s Ergonomics Checklist for Material Handling
Condition
REPETITION
High-speed process line or work
presentation rates
Similar motions every few seconds
Observed signs of fatigue
WORKSTATION DESIGN
Work surface too high or low
Location of materials promotes
reaching
Angle/orientation of containers
promotes non-neutral positions
Spacing between adjacent transfer
surfaces promotes twisting
Obstructions prevent direct access to
load/unload points
Obstacles on floor prevent a clear path
of travel
Floor surfaces are uneven, slippery, or
sloping
Hoists or other power lifting devices
are needed but not available
X if a Concern
Comments
Kodak’s Ergonomics Checklist for Material Handling, cont.
LIFTING AND LOWERING
Heavy objects need to be handled
Handling bulky or diffi cult-to-grasp
objects
Handling above the shoulders or
below the knees
Lifting to the side or unbalanced
lifting
Placing objects accurately/precisely
Sudden, jerky movements during
handling
One-handed lifting
Long-duration exertions (static work)
PUSHING/PULLING/CARRYING
Forceful pushing/pulling of carts or
equipment required
Brakes for stopping hand
carts/handling aids are needed but
not available
Carts or equipment design promotes
non- neutral postures
Long-distance carrying (carts not
available)
Kodak’s Ergonomics Checklist for Material Handling, cont.
CONTAINERS/MATERIALS
Lack adequate handles or gripping
surfaces
Are unbalanced, unstable, or contents
shift
Obstructs leg movement when being
carried
OTHER
Inappropriate work techniques used
Buildup of process material /product
increases worker effort
Personal protective equipment
needed but not available/used
TOTAL SCORE (Optional)
To score, add up the total
number of Xs identified.
Look for Clues – General Checklists
NIOSH Manual Material Handling (MMH) Checklist
Source: http://www.cdc.gov/niosh/docs/97-117/eptbtr5f.html
NIOSH Manual Material Handling (MMH) Checklist
"No" responses indicate potential problem areas which should receive further investigation.
1. Are the weights of loads to be lifted judged acceptable by the workforce?
2. Are materials moved over minimum distances?
3. Is the distance between the object load and the body minimized?
4. Are walking surfaces
level?
wide enough?
clean and dry?
5. Are objects
easy to grasp?
stable?
able to be held without slipping?
6. Are there handholds on these objects?
7. When required, do gloves fit properly?
8. Is the proper footwear worn?
9. Is there enough room to maneuver?
10. Are mechanical aids used whenever possible?
11. Are working surfaces adjustable to the best handling heights?
12. Does material handling avoid
movements below knuckle height and above shoulder height?
static muscle loading?
sudden movements during handling?
twisting at the waist?
extended reaching?
13. Is help available for heavy or awkward lifts?
14. Are high rates of repetition avoided by
job rotation?
self-pacing?
sufficient pauses?
15. Are pushing or pulling forces reduced or eliminated?
16. Does the employee have an unobstructed view of handling the task?
17. Is there a preventive maintenance program for equipment?
18. Are workers trained in correct handling and lifting procedures?
[ ]yes
[ ]yes
[ ]yes
[ ]no
[ ]no
[ ]no
[ ]yes
[ ]yes
[ ]yes
[ ]no
[ ]no
[ ]no
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]yes
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
[ ]no
Look for Clues – Risk Factor
Checklists
Hazard Evaluation Checklist for Lifting, Carrying, Pushing
or Pulling
Source: T. R. Waters, “Manual Materials Handling”, in: Physical and
Biological Hazards of the Workplace (Second edition). Edited by P. Wald and
G. Stave. New York: John Wiley and Sons, 2002.
Hazard Evaluation Checklist for Lifting, Carrying, Pushing
or Pulling Risk Factors
YES
NO
1. General
1.1 Does the load handled exceed 50 lb.?
1.2 Is the object difficult to bring close to the body because of its size, bulk, or
shape?
1.3 Is the load hard to handle because it lacks handles or cutouts for handles, or
does it have slippery surfaces or sharp edges?
1.4 Is the footing unsafe? For example, are the floors slippery, inclined, or
uneven?
1.5 Does the task require fast movement, such as throwing, swinging, or rapid
walking?
1.6 Does the task require stressful body postures, such as stooping to the fl oor,
twisting, reaching overhead, or excessive lateral bending?
1.7 Is most of the load handled by only one hand, arm, or shoulder?
1.8 Does the task require working in extreme temperatures, with noise, vibration,
poor lighting, or airborne contaminants?
1.9 Does the task require working in a confi ned area?
2. Specific
2.1 Does lifting frequency exceed 5 lifts per minute?
2.2 Does the vertical lifting distance exceed 3 feet?
2.3 Do carries last longer than 1 minute?
2.4 Do tasks that require large sustained pushing or pulling forces exceed 30
seconds duration?
2.5 Do extended reach static holding tasks exceed 1 minute?
Look for Clues – Risk Factor
Checklists
Washington State Department of Labor and Industries –
Hazard Zone Checklist for Awkward Postures
Source:
http://www.lni.wa.gov/Safety/Topics/Ergonomics/ServicesResources/Tools/
Washington State Department of Labor and Industries –
Hazard Zone Checklist for Awkward Postures
Calculator Exercise
Determine risk factors using checklist
 Use Washington State “calculator to
analyze Lifting Jobs” to determine if the
task is hazardous

Prioritize Jobs for Improvement
•The frequency and severity of the risk factors you have
identified that may lead to injuries
•The frequency and severity of complaints, symptoms,
and/or injuries
•Technical and financial resources at your disposal
•Ideas of workers for making improvements
•Difficulty in implementing various improvements
•Timeframe for making improvements
Make Improvements
Questions for selecting improvement options:
o
Reduce or eliminate most or all of the identified risk factors?
o
Add any new risk factors that have not been previously identified?
o
Be affordable for our organization (e.g., is there a simpler, less
expensive alternative that could be equally effective)?
o
Affect productivity, efficiency, or product quality?
o
Provide a temporary or permanent “fix”?
o
Be accepted by employees…will it affect employee morale?
o
Be able to be fully implemented (including training) in a
reasonable amount of time?
Follow Up
Questions for evaluating improvements:
o
Reduced or eliminated fatigue, discomfort, symptoms, and/or
injuries?
o
Been accepted by workers?
o
Reduced or eliminated most or all of the risk factors?
o
Caused any new risk factors, hazards, or other problems?
o
Caused a decrease in productivity and efficiency?
o
Caused a decrease in product and service quality?
o
Been supported with the training needed to make it effective?
Improvements
• Easier Ways to Manually Lift, Lower, Fill, or Empty
Containers
– Management Guidelines for Safer Lifting
– Employee Guidelines for Safer Lifting
• Easier Ways to Manually Carry Containers
• Alternatives to Manual Handling of Individual Containers
Specific Improvements
•
Plan the workflow to eliminate unnecessary lifts.
•
Organize the work so that the physical demands and work pace
increase gradually.
•
Minimize the distances loads are lifted and lowered.
•
Position pallet loads of materials at a height that allows workers to
lift and lower within their power zone (Between 30 to 50 inches).
•
Avoid manually lifting or lowering loads to or from the floor.
•
Convert a carry to a push or pull
Review of Improvement Options
Improvement Options for Lifting
Lifting Device
Team Lift
Turntable
Improvement Options for Lifting
Adjustable Work
Platforms
Portable Stairs
Adjustable Work
Surfaces
Improvement Options for Awkward
Postures
Remove Sides of
Receptacles
Add Handles to
Containers
Workstation CutOuts
Other Improvement Options
o
Washington State Ergonomics Idea Bank
o
http://www.lni.wa.gov/safety/topics/reducehazard
s/ergobank/default.asp
Reference
Ergonomic Guidelines for Manual Material Handling
NIOSH 2007-131
http://
www.cdc.gov/niosh/docs/2007-131/
References
o
o
o
o
o
o
o
o
o
o
o
Musculoskeletal Disorders and Workplace Factors, NIOSH Publication No. 97141, 1997.
Ergonomic Guidelines for Manual Material Handling, NIOSH Publication No. 2007-131,
2007.
Bureau of Labor Statistics Annual Survey, 1996.
Washington State Department of Labor and Industries SHARP Technical Report 40-62002, 2002.
Elements of Ergonomic Programs, NIOSH Publication No. 97-117, 1997.
T. R. Waters, “Manual Materials Handling”, in: Physical and Biological Hazards of the
Workplace (Second edition). Edited by P. Wald and G. Stave. New York: John Wiley
and Sons, 2002.
Kodak's Ergonomic Design for People at Work, Second Edition, Hoboken, NJ:
John Wiley & Sons, Inc., 2007.
Washington State Department of Labor and Industries Ergonomics Website:
o http://www.lni.wa.gov/safety/topics/ergonomics/default.asp
Cornell University Ergonomics Website:
o http://ergo.human.cornell.edu
University of Michigan 3D Static Strength Prediction Program Website:
o http://www.engin.umich.edu/dept/ioe/3DSSPP
Ohio State University Biodynamics Website:
o http://biodynamics.osu.edu/research.html
Tier II – Analysis Tools
o
Quantitative Analysis Tools
o
NIOSH Lifting Equation
o
o
ACGIH Threshold Limit Values for Lifting
o
o
http://www.engin.umich.edu/dept/ioe/3DSSPP/
Ohio State Lumbar Motion Monitor
o
o
www.acgih.org/store
University of Michigan 3D Static Strength
Prediction Program
o
o
http://www.cdc.gov/niosh/94-110.html
http://biodynamics.osu.edu/research.html
Snook’s Psychophysical Tables
o
http://libertymmhtables.libertymutual.com/CM_LMTablesW
eb/taskSelection.do? action=initTaskSelection