The Back and
Material Handling Issues
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
The Spinal Column
Cervical
Thoracic
Lumbar
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
The Basic Structure
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Epidemiology of Back Injuries
Short Term or acute effects:
• Sharp Surfaces
• Dropped Material
• Struck-by Moving Materials
• Mechanical Stress
• Slips and Falls
• “Simpler” Cause and effect relationship
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Epidemiology
Chronic or Long Term Effects
• Back Ache or Pain
• Disc Degeneration
• Cause and effect not
as simple, more difficult
to analyze
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Return to Work
• Out more than 6 months only 50% chance
of returning
• One year only 25%
• Management and Practitioner Training
One study showed that claims dropped from
200K to 20K per year by providing modified
work and conservative treat
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Material Handling
• Lifting/Lowering
• Pushing/Pulling
• Carrying
• Weights and Forces
• Frequency of Activities
• Load Center of Gravity
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Material Handling
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Sorenson Video 3 decompressor
are needed to see this picture.
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Job Risk Factors
• Weight of the Object
• Location (position of load
w.r.t. worker)
• Frequency of Lifts
• Stability of the Load
• Hand Coupling
• Workplace Geometry
Twisting/Stooping
• Environmental Factors
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Personal Risk Factors
• Gender
• Age
• Anthropometry
• Lift technique
• Attitude
• Strength
• Training
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Examples of
Manual Handling Controls
• Avoid extreme range of motion when lifting
• Redesign work station/work area to allow
freedom of movement
• Provide handles on material handling equipment
• Provide lift-assist devices and tables
• Unit Load Concept
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Job Design
• Can reduce one-third of
compensable LBP
• Minimize reach and lift
distances
• Keep off floor
• Work station design
• Frequency
• Relax time standard
• Rotation
• Work-Rest allowances
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Job Design
• Minimize Weight
• Mechanical aids
• Carton capacity
• Balance contents
• Convert
• Carry to push/pull
• Push over pull
• Use large wheels
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Training
• Focus on awareness and
avoidance
• Get object as close to body
as possible
• Planning
• Use of handling aids
• Back Schools
• Strength and fitness
important
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
NIOSH Lifting Equation
1991 Version
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
NIOSH Lifting Equation
• Objective: Reduce occurrence of
lifting-related LBP
• 1981 and 1991 equations
• 1981 limited to sagittal plane
• 1991 includes asymmetry and coupling
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Disqualifiers for Use
• One handed lifts
• More than 8 hours
• Seated or kneeling
• Restricted work space
• Unstable Objects
• Carrying, pushing or
pulling while lifting
• Wheelbarrows
or shovels
• High speed motion
• Unreasonable
foot/floor coupling
• Unfavorable
environment
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Definition of Terms
• RWL = Recommended
weight limit
• LC = Load constant
• HM = Horizontal
multiplier
• VM = Vertical
multiplier
• DM = Distance
multiplier
• AM = Asymmetric
multiplier
• FM = Frequency
multiplier
• CM = Coupling
multiplier
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
1991 Equation
RWL = LC x HM x VM x DM x AM x FM x CM
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
1991 Guide
• Compare RWL to Actual Load (L)
• If Greater than or equal to 1 problem
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Lifting Index
L
RWL
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
1991 Multipliers
• LC = 51 Pounds
• HM = 10/H
• VM = 1-.0075 x / V-30/
• DM = .82 + (1.8/D)
• AM = 1 – (.0032 x A)
• FM go to Table
• CM go to Table
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
NIOSH Worksheet
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
Lifting Example
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
NIOSH Workshop
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ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
NIOSH Workshop
Start of Lift
End of Lift
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
NIOSH 1991 Lifting Calculator
NIOSH Lifting Guidelines -- Job Analysis
Notes Packer
Enter values in Yellow area.
For Composite Lifting Index (CLI) to be computed correctly,
sort tasks in decreasing order based on LI by pressing button.
Sort
Task
No.
1
2
3
4
5
6
7
8
9
CLI = 0.3
1991 Guide
RWL
LI
24.3
0.2
12.2
0.4
11.0
0.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Object Wt. Hand Location (inches)
1981 Guide
(lbs)
Origin
Destination
AL
MPL L (avg)L (max) H
V
H
V
29.0
87.0
5.0
18.0 30.0 15.0
40.0
13.3
39.9
5.0
18.0 30.0 30.0
15.0
11.4
34.1
5.0
18.0 30.0 30.0
52.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Asymmetry Period Freq
(degrees) (hours) (#/min) Handle
Orig Dest
P
F
C
15
0
4.0
0.4
Poor
15
0
4.0
0.4
Poor
15
0
4.0
0.4
Poor
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
WISHA
Calculator for Analyzing Lifting Operations
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
www.lni.wa.gov/wisha/ergo/calculator/ergo_workshopIE.htm
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
WISHA Workshop
QuickTime™ and a
Sorenson Video 3 decompressor
are needed to see this picture.
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
WISHA
If the job is a hazard
• Reduce weight of load
• Increase weight of load so that it
requires mechanical assist
• Reduce the capacity of the container
• Etc.
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
References
• Applications guide for the revised NIOSH
lifting equation – On CD
• Elements of Ergonomic Programs – On CD
• Musculoskeletal Disorders and Workplace
Factors – On CD
• Work Practices Guide for Manual Lifting
NIOSH 81-122
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING
What does the worker need to
know from this presentation?
ERGONOMICS :: TRAIN-THE-TRAINER PROGRAM :: THE BACK & MATERIAL HANDLING