Excellence Through Innovative Research
Digital Human Modeling for Ergonomics
Assessment of Patient Lifting by Paramedics
Akiev Samson
Graduate Research Associate
Department of Systems Science and Industrial Engineering
Binghamton University (State University of New York)
Binghamton, NY 13902
Feb 27th, 2009
www.wise.binghamton.edu

Agenda
• Ergonomics
• Work-Related Musculoskeletal Disorders (WMSDs)
• Patient Handling
• Paramedic Profession, Statistics
• Conventional Ergonomics vs Digital Human Modeling (DHM)
• Research Objectives and Outline
• Uniqueness and Significance
• Experiments
• Validation, Anthropometric Effect, Adjustment, Postural Effect
• Results
• Recommendations
• Conclusions and Future Work
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Ergonomics
Ergonomics
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Work-Related Musculoskeletal Disorders (WMSDs)
Repetitive Motion
WMSDs
Injuries
Repetitive Strain
Injuries
Cumulative
Trauma Disorders
Occupational
Cervicobrachial
Disorders
 Construction Overuse Syndrome
 Manufacturing
 Mining Regional
 Office Work Musculoskeletal
Disorders
Soft Tissue Orders
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Cost of WMSDs
Construction:
50,000 Claims
$1,000,000,000
Manufacturing: 45,000 Claims
$500,000,000
Administrative: 20,000 Claims
$200,000,000 “Increase in
Ergonomic
Educational: 8,000 Claims Injuries, Worker
$75,000,000 Compensation
Claim..”
Healthcare
Healthcare: Washington
36, 000 Claims
Domain State
$340,000,000
“Just for Washington
Highest Risk
State” $1 in $3
for 2 Million
Rate of Spent on
WRMSDs Lost
1 in 5 Injuries WRSMDs Workdays
Reported Twice the
WRMSDs Working
Population
Center for Occupational and Environmental Medicine, 2003.
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Safety and Health Assessment and Research for Prevention (SHARP), 2005
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Motivation
Du, 2005
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Patient Handling in Healthcare
“Paramedics do not have the option of Time”
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Paramedic Profession
“Less emphasis on
“More than half have “Many devices Ambulance
patient lifting
some form of WMSD” and many injuries” Crashes
training”
Occupational Fatalities Shootings
Fire Breakout
Patient Lifting
Repetitive
Back Injuries
Bending
Awkward
Bending Hazardous
Material
Excessive
Sickness
Work
“Complex and
challenging” “Lack of Treating the
documentation of “Many EMTs were Diseased
data” volunteers”
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Paramedics: Statistics
Okada et al. (2005)
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Conventional Ergonomics vs DHM
“Lumbar Motion “Electromyography”
Monitor” Reach Zone
TSB Simulation
Analysis
• Postural • Muscle • Stress
BORG’s
Angles Activity Perception
LMM Vision Analysis EMG
Scale
Collision Detection
• 3DSSPP • Electrodes • Survey
Digital Humans
DHM
Never
Lower Back Technology Animation
Say ‘No’ !!
Analysis
Static Strength
Fatigue Analysis
Prediction
Metabolic Energy
Expenditure
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Research Objectives
• To demonstrate the effectiveness of DHM software for
ergonomics assessment of paramedic patient handling
• To study the influence of anthropometry of paramedics on
lower back stress
• To study the influence of postural variables on lower back
stress during patient lifting
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Research Outline
Quantifying Lower Back Defining Team Roles through
Stress: Validation Anthropometry
“Challenging
Environment”
Adjustment of Stretcher and
Postural Variables Gurney
DHM Software
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Uniqueness and Significance
“Innovative “Implementation of a
Technology to Study Cost Effective Solution
Healthcare to Study Healthcare
Ergonomics” Ergonomics that will
Benefit Healthcare
Professionals in the
long term”
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Research Methodology
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Excellence Through Innovative Research
Validation of DHM Software as a Tool
to Study Patient Lifting
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Validation
Replication of Images from Previous Research
10 Male Paramedics
Variable
Anthropometry
48 Kilogram Patient
Difference in Back
Stress between Teams
Average Postural Angles
Lavender et al. (2000a, 2000b)
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Results: Validation
Stretcher Side
Stretcher- Side Follower
Follower
Paramedic
Paramedic
Stretcher- Side
Follower Follower
Paramedic
Bedside
Patient Leader
Gurney Side Patient
Patient Paramedic:
Paramedic Patient Patient
Leader
Patient Leader
Kneeling
Leader
Bed-side
Paramedic:
Standing
Backboard
Patient
Stairchair
Stairs
Stairs
Stretcher
Stairchair Backboard Stretcher
Bed
Stairs
Stretcher Gurney
Bed
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Results: Validation (Contd.)
48 Kg Patient
“Paramedics will experience > 3400 N at least once during a
complete transfer task”
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Excellence Through Innovative Research
Effect of Anthropometry
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Methodology for Simulating Postures
Get
Anthropometries
Identify Grip
Points
Identify
Dimensions which
are (can be) Fixed
Height
of Bed
Height of
Height
Stretcher
Distance between Grips
of
(Stretcher, Backboard & A
Gurney
Stairchair)
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Methodology for Simulating Postures (Contd.)
A
Position Body
with Respect
to Grip Points
Identify
Dimensions
(angles) which
can be Varied
Wrist
Angles
Validate
Postures
Trunk
Flexion
Shoulder
Distance between
Abduction
Hands (Gripping a
Bed Sheet)
Paramedic Height Analyze
Patient Weightth 5th 50th 95th
5th 95th
50
Repeat for
Other Digital
Humans
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Results: Effect of Anthropometry – Paramedic Height
“
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Excellence Through Innovative Research
Influence of Stretcher and Gurney Height
Adjustment on Lower Back Stress for
Paramedics with Different Heights
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Methodology for Simulating Tasks
5th 50th 95th
5th 50th 95th
Paramedic Height
5th 50th 95th
Paramedic Weight
Patient Weight
Stretcher and Gurney
Height 53 72.5 92
cm cm cm
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Results: Stretcher Side Paramedic
4900 N
3750 N
2870 N
3200 N
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Main Effects: Stretcher Side Paramedic
4200 N
3000 N
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Contour Plot: Stretcher Side Paramedic
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Results: Gurney Side Paramedic
7600 N
6500 N
6050 N
5900 N
5750 N 5550 N
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Contour Plot: Gurney Side Paramedic
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Stretcher vs Gurney Side
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Excellence Through Innovative Research
Postural Variables
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Different Postural Variables
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Results: Trunk Flexion vs Shoulder Rotation
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Results: Trunk Flexion vs Shoulder Separation
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Results: Trunk Flexion vs Shoulder Elevation
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Results: Trunk Flexion vs Elbow Angle
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Summary of Results
• Team Role
• Leader in a safer role compared to follower
• Gurney Side role strenuous
• Standing safer than kneeling
• Anthropometry of Paramedic
• Shorter paramedics encounter lower back stress
• Could influence lower back stress of team member
• Height Adjustment is Crucial
• Degree of adjustment more for stretcher side than gurney side
• Postural Variables
• Stress trends at 0 , 10 , 20 and 30 , 40 and 50
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Proposed Solutions
• Ideal: Shorter Paramedics
• Not the Most Effective: Shortage of Paramedics
Recruitment
• Less Strength: Less Strenuous Task
• Equal Strength: Alternate between Tasks
Pre-planning
• Handles as Close as Possible to Patient Body
• Use of DHM to Evaluate Equipment
Equipment
“Effort from Upper Management to Invest in
Patient Lifting Equipment”
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Limitations
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Conclusions and Future Work
Stryker, 2007
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