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Build it Better: Construction Ergonomics
Work design tips,
recommendations, and best practices
Edison Electric Institute Occupational Safety & Health Committee Conference, Fall 2016
Carolyn M. Sommerich, PhD, CPEThe Ohio State University
College of Medicine - School of Health and Rehabilitation Sciences
College of Engineering - Department of Integrated Systems Engineering
Discussion Points
• Ergonomics - what’s that?
• Construction ergonomics
– Worker health and safety statistics
– Know your workers
– Injury risk factors
– Interventions - work design tips, recommendations, & best practices to reduce risk factor exposure
What is Human Factors/ Ergonomics?
• Human factors/ergonomics is a body of information about human abilities, limitations, behaviors, and other human characteristics that are relevant to design.
• Human factors engineering is the application of human factors information to the design of tools, machines, systems, tasks, jobs, and environments for productive, safe, comfortable human use.
modified from Chapanis (1996)
Key premise of HF/E
• A key goal, when applying ergonomics principles, is to design systems and tasks well within the capacity of the humans that will use them…
If ( task requirements ≥ human capacity )
Then adverse outcomes are more
likely to occur,
such as… reduced productivity, increased injuries, reduced quality, increased turnover, etc…
Potential benefits of applying HF/E principles
• increase safety
• improve system performance
• increase reliability
• improve maintainability
• improve the working environment
• increase human comfort
• increase ease of use
• increase user acceptance
• increase aesthetic appearance
• reduce turnover
• increase compliance
• increase economy of production
• reduce errors
• reduce personnel requirements
• reduce training requirements
• reduce fatigue and physical stress
• reduce boredom and monotony
• reduce losses of time and equipment
Adopted and modified from Chapanis, A. (1996). Human Factors in Systems Engineering. New York: John Wiley & Sons, Inc.
Example…
Design Problem Case 1:
• Symptom: Shrek performers at Universal Orlando had issues with shoulder, neck, and lower back pains. Costs: 21 first aid cases, 26 recordable injuries, 622 light duty days, and 49 restricted/lost work days from June 2004 to March 2006 with a direct cost of over $80,000.
Design Problem Case 1:
• Symptom: Shrek performers at Universal Orlando had issues with shoulder, neck, and lower back pains. Costs: 21 first aid cases, 26 recordable injuries, 622 light duty days, and 49 restricted/lost work days from June 2004 to March 2006 with a direct cost of over $80,000.
• Root cause: issues identified were weight of the costume, body positioning in the costume, ventilation, and visibility.
Design Problem Case 1:
• Symptom: Shrek performers at Universal Orlando had issues with shoulder, neck, and lower back pains. Costs: 21 first aid cases, 26 recordable injuries, 622 light duty days, and 49 restricted/lost work days from June 2004 to March 2006 with a direct cost of over $80,000.
• Root cause: issues identified were weight of the costume, body positioning in the costume, ventilation, and visibility.
• Intervention: Redesign costume - cost $1700 labor and materials
– Weight reduction: redesign harness with lighter materials; eliminate unnecessary layers (10 lb savings)
– Improve body posture: separate head from the body to allow movement and balance weight inline with the spine (also aids neck mobility and visibility)
– Improve ventilation: add opening at back of the head to allow for air flow assisted by a battery powered pancake fan. The separation of the head (and added mobility to move the neck) increased visibility.
Design Problem Case 1:
• Symptom: Shrek performers at Universal Orlando had issues with shoulder, neck, and lower back pains. Costs: 21 first aid cases, 26 recordable injuries, 622 light duty days, and 49 restricted/lost work days from June 2004 to March 2006 with a direct cost of over $80,000.
• Root cause: issues identified were weight of the costume, body positioning in the costume, ventilation, and visibility.
• Intervention: Redesign costume - cost $1700 labor and materials
– Weight reduction: redesign harness with lighter materials; eliminate unnecessary layers (10 lb savings)
– Improve body posture: separate head from the body to allow movement and balance weight inline with the spine (also aids neck mobility and visibility)
– Improve ventilation: add opening at back of the head to allow for air flow assisted by a battery powered pancake fan. The separation of the head (and added mobility to move the neck) increased visibility.
• Outcome: 0 injuries & 0 lost time after March 2006 implementation
Relevance to construction?
Relevance to construction?
Occupational safety: & ergonomics:Recognize - Evaluate - Control
• Recognize– Workplace hazards
• Evaluate hazard exposure and risk – What concentration, for how long, and how often
• Control hazard (hierarchy)
– Eliminate/remove hazard/risk factor
– Engineering controls• Make changes to workplace, equipment, task, methods,
product design, etc.
– Administrative controls• Reduce exposure duration
• PPE, training
Approach to
Occupational safety & ergonomics:Recognize - Evaluate - Control
• Recognize– Workplace hazards
• Evaluate hazard exposure and risk– What concentration, for how long, and how often
• Control hazard (hierarchy)
– Eliminate/remove hazard/risk factor
– Engineering controls• Make changes to workplace, equipment, task, methods,
product design, etc.
– Administrative controls• Reduce exposure duration
• PPE, training
Approach to
Occupational safety & ergonomics:Recognize - Evaluate - Control
• Recognize– Workplace hazards
• Evaluate hazard exposure and risk– What concentration, for how long, and how often
• Control hazard (hierarchy)
– Eliminate/remove hazard/risk factor
– Engineering controls• Make changes to workplace, equipment, task, methods,
product design, etc.
– Administrative controls• Reduce exposure duration
• PPE, training
Approach to
Occupational safety & ergonomics:Recognize - Evaluate - Control
• Recognize– Workplace hazards
• Evaluate hazard exposure and risk– What concentration, for how long, and how often
• Control hazard (hierarchy)
– Eliminate/remove hazard/risk factor
– Engineering controls• Make changes to workplace, equipment, task, methods,
product design, etc.
– Administrative controls• Reduce exposure duration
• PPE, training
Approach to
Work System Components
Methods
Tasks
Work
OrganizationEnvironment
Workers
Tools and Equipment
Product, performance,…
Worker health outcomes
Physical ergonomics -some useful characteristics to
know about people…
• How they are affected by environmental conditions
• Fatigue/endurance limits
• Anthropometric characteristics
• Muscular strength
• Sense capabilities (hearing, touch, sight)
• Dexterity
Physical ergonomics -some useful characteristics to
know about people…• How they are affected by environmental conditions
• Fatigue/endurance limits
• Anthropometric characteristics
• Muscular strength
• Sense capabilities (hearing, touch, sight)
• Dexterity
• And how these vary across a work force…
Physical ergonomics -some useful characteristics to
know about people…• How they are affected by environmental conditions
• Fatigue/endurance limits
• Anthropometric characteristics
• Muscular strength
• Sense capabilities (hearing, touch, sight)
• Dexterity
• And how these vary across a work force…
• And how they change with age…
Ergonomics -some useful characteristics to
know about people…• How they are affected by environmental conditions
• Fatigue/endurance limits
• Anthropometric characteristics
• Muscular strength
• Sense capabilities (hearing, touch, sight)
• Dexterity
• And how these vary across a work force…
• And how they change with age…
• And how personality, cognitive, and psychosocial factors interact with all of these
Psychosocial perceptions - some examples
for construction employees
Sloan Center on Aging & Work: Talent Pressures and the Aging Workforce: Responsive Action Steps for the Construction Sector, 2010
Who works in construction?
9.3% of workers in
construction are
female; about
200,000 women work
in production
(laborers, trades, etc.)
29% of workers in construction
are Hispanic/Latino.
Mean age of construction workers is
42.6 years of age; 14.5% are over 55.
Recognizing differences in characteristics
Men & Women & Body Size
Source: KHE Kroemer et al, 1997, Engineering Physiology: Bases of Human Factors/Ergonomics.
Height
Hand Length
Forward Grip Reach
Overhead Grip Reach
Forward
Overhead
Recognizing differences in characteristics
Ethnicity & Body Size
Source: Centers for Disease Control, National Health Statistics Reports, 2008
Average height
Recognizing differences in characteristicsAccommodating differences in body size
Example in practice:
• Drywall stilts, to allow shorter employees to get closer to work without use of ladder
Recognizing differences in characteristicsAccommodating differences in body size & shape
Example in practice:
• PFAS designed for women
•Provide gloves in multiple sizes
Recognizing differences in characteristics
Men & Women & Strength
Female Body Strength, Compared to Males
Recognizing differences in characteristics
Men & Women & Strength & Aging
* Compared to a 24 year-old male
Recognizing differences in characteristicsAccommodating differences in strength
Example in practice:
• Use powered vacuum lift for heavy lifting
Before
After
Recognizing differences in characteristics
Vision & Aging
• Beginning in mid-40’s for many adults, normal effects of aging include…
– Need for more light to see well
– Difficulty with near vision (presbyopia)
– Glare sensitivity increases
– Changes in color perception
– Reduced tear production
Recognizing differences in characteristicsAccommodating differences in visual capabilities
Example in practice:
• Provide additional sources of light
Recognizing differences in characteristicsPersonal health
BMI = 703 x weight (lbs)(ht (in))2
25<BMI<29.9 30≤BMI
Weight statistics are similar to population as a whole: 69.2% of US adult pop. is overweight
(CDC, Health, US, 2012).
Obesity and smoking are risk factors for occupational injury
Energy requirements for task performance increase with weight. Smoking decreases endurance and physical performance.
Work System Components
Methods
Tasks
Work
OrganizationEnvironment
Workers
Tools and Equipment
Product, performance,…
Worker health outcomes
Worker capabilities and limitations Systems view of work - components and interactions •Recognize•Evaluate•Control
Recognizing workplace hazards
• Injury statistics
• Research studies
• Assessment tools
• Safety experts
• Employee insights
2014 BLS Injury statistics
Fatal
Non-fatal
2012 BLS Injury statistics
Fatal
Non-fatal
2014
20142014
2014
Recognize through Research:Relevant to slips, trips, falls in construction
Recognize through Research:Relevant to slips, trips, falls in construction
Recognize through Research:Relevant to slips, trips, falls in construction
From the literature, concerning Personal Fall Arrest System (PFAS) usage:• Some workers are not supplied with PFAS (Cattledge et
al. , 1996)
• Work environment does not allow the use of PFAS (Cattledge et al., 1996)
• e.g. no tie-off point
• From workers’ perspectives it reduces productivity and makes them uncomfortable (Sa, 2005)
• Lack of fall protection training and company’s enforcement (Janiack, 1998; Johnson et al. , 1998)
Recognize through Research:Relevant to slips, trips, falls in construction
Recognize through Research:Relevant to slips, trips, falls in construction
Recognize through Research:Relevant to slips, trips, falls in construction
Recognize through Research:Musculoskeletal injuries due to overexertion
and other causes
Identified risk factors:Excessive force
Excessive repetitionAwkward postures
Lack of restVibration
Recognize through Assessment Tools:Musculoskeletal injuries due to overexertion
and other causes
Identified risk factors:Excessive force
Excessive repetitionAwkward postures
Lack of restVibration
Evaluation methods include tools such as:•NIOSH Lifting Equation•ACGIH TLVs for lifting and hands•Checklist tools (QEC, etc.)…..
Vibration
Vibration - recognition of adverse effects on health
• Hand-arm vibration is associated with:– Vibration White Finger (VWF) / Hand-Arm
Vibration Syndrome (HAVS)• Prevalence higher with…
– increased age,
– exposure to higher levels of hand-arm vibration (HAV),
– exposure to colder climate in those exposed to HAV Burstrom et al. 2010
– Carpal Tunnel Syndrome (CTS)
• Whole-body vibration is associated with:– Circulatory, bowel, respiratory, muscular and back
disorders
– Fatigue, insomnia, stomach problems, headache, …
Vibration - recognition of effects on grip strength
Vibration
Images from http://resource.isvr.soton.ac.uk/HRV/VIBGUIDE.htm
WBV relevant frequencies: 0.5 to 80 Hz
HAV relevant frequencies: 5 to 1500 Hz
Hand-Arm VibrationEvaluation
• Vibration total value
• Daily vibration exposure, A(8)
– When using one tool:
– When using more then one tool:
EU Guide to good practice on Hand-Arm Vibration, v7.7, 2006
T=daily exposure duration;
T0 = 8 hrs
Hand-Arm VibrationEvaluation
• Example:
EU Guide to good practice on Hand-Arm Vibration, v7.7, 2006
grinder chipper
vibration emission, m/s2 7 16
use, hr/day 2.5 0.25
A(8), each tool 3.9 2.8
=7*sqrt(2.5/8) =16*sqrt(0.25/8)
A(8), total exposure 4.8
Hand-Arm VibrationEvaluation
• Example:
EU Guide to good practice on Hand-Arm Vibration, v7.7, 2006
grinder chipper
vibration emission, m/s2 7 16
use, hr/day 2.5 0.25
A(8), each tool 3.9 2.8
=7*sqrt(2.5/8) =16*sqrt(0.25/8)
A(8), total exposure 4.8
Hand-Arm VibrationEvaluation
• Example:
EU Guide to good practice on Hand-Arm Vibration, v7.7, 2006
grinder chipper
vibration emission, m/s2 7 16
use, hr/day 2.5 0.25
A(8), each tool 3.9 2.8
=7*sqrt(2.5/8) =16*sqrt(0.25/8)
A(8), total exposure 4.8
Vibration - Evaluation tools
• Hand-arm vibration
– Look it up
• Tool databases
– Measure it
– Factors that can affect HAV
• Type of tool, tool condition, materials, etc.
Vibration - controls for HAV• Substitute – mechanization, automation
• Equipment selection –
– Right tool for the job
– Procurement policy
• Check tool’s vibration emission value and assessment method
• Check that tool’s exhaust does not blow on hands
• Tool maintenance
• Review work methods
• Work schedule (job rotation, piece rate, …)
• Training
• Worker input
• Use caution: Rubber or other resilient materials wrapped around tool handle can actually amplify vibration
Vibration - controls for HAV• Anti-vibration Gloves
• ?
• Hewitt et al.’s conclusions about AV gloves:– Unreliable devices for controlling vibration exposure
– Generally cannot reduce vibration exposure from low-frequency tools
– Can somewhat reduce frequency-weighted vibration transmission to palm of hand from powered hand tools, but not to fingers
– Often adverse “ergonomics” response occurs when wearing AV gloves
Controls for other risk factors in Construction
National Institute for Occupational Safety & Health, 2007
Available as pdf or webpages
Controls to reduce force
Kneeling Creeper with Chest
Support
Mechanical LiftsAfterBefore
Controls to reduce force
Pneumatic Drywall Finishing
Tool
Powered Caulking Guns
Before After
Before
After
Controls to reduce force
Skid Plate for Hose Pulling
Before
After
Controls to reduce awkward postures
Stand-Up Screw Gun
Rebar-Tying Tool
After
Before
Before
After
Controls to reduce awkward postures
Overhead drilling: Inverted drill press
After
Before
Controls to reduce awkward postures
Offset Tool Handles
Upright Snips
AfterBefore
Controls to reduce slip, trip, fall hazards
• Worker & management engagement
• Housekeeping• Staging locations• Clear, designated walkways• Cords and hoses• Lighting• Use appropriate, intact devices for elevating workers• …
• For work ≥ 6’, appropriate safety devices and measuresDuty to have fall protection. - 1926.501
• Work shoes with non-skid soles
Diagram by Karn G. Bulsuk (http://www.bulsuk.com)
Handtool Selection Tips
General suggestions:• Use a tool rather than the hand.• Use a fixture rather than a hand.• Use a power tool if possible, if force exertion is required
repeatedly or for extended duration, but address the added weight.
• Use tools appropriate for right and left handers.
Handtool Selection Tips
• Tool handles should be:o non-slipo non-sweato shock attenuatingo temperature insulated
• Tool handle shape and size:o Span (7.5-8.5 cm)o No digital profiling (no finger ridges)o Long, to avoid digging into palmo Try T-bar in place of screwdrivero Cylinder dia: 3-5 cm.
Handtool Selection Tips
• Tool properties:o To reduce force
• Minimize weight• Center of mass: for power tool it should be over the hand; for
striking tool it should be near head• Provide auxiliary handle for heavy tools, awkward positions• Provide articulating arms, balancers
• To reduce awkward postures• Bend tool handle• Change orientation of part• Provide arm rests
• To reduce temperature extremes• Control direction of power tool exhaust • Insulate handle• Provide gloves
Intervention resources Construction ergonomics
• Ohio BWC
– Ergonomics Best Practices for the Construction Industry
– Safety Grant Program
• NIOSH
– Constructionhttp://www.cdc.gov/niosh/construction/
– Highway work zone safety - construction equipment visibilityhttp://www.cdc.gov/niosh/topics/highwayworkzones/BAD/
– Simple Solutions for Construction Workershttp://www.cdc.gov/niosh/docs/2007-122/
• CPWR - Center for Construction Research and Traininghttp://www.cpwrconstructionsolutions.org/
Intervention resources Vibration
• US Army Public Health Command Vibration Pocket Guidehttp://phc.amedd.army.mil/PHC%20Resource%20Library/VIBRATION_POCKET_GUIDE_06_17_2013.pdf
• University of Southamptom Institute of Sound and Vibration Research– Good practice guides for HAV and WBV
http://resource.isvr.soton.ac.uk/HRV/VIBGUIDE/HAV%20Good%20practice%20Guide%20V7.7%20English%20260506.pdf
http://resource.isvr.soton.ac.uk/HRV/VIBGUIDE/2008_11_08%20WBV_Good_practice_Guide%20v6.7h%20English.pdf
• UK Health & Safety Executive - Vibration at work– Explanation, exposure calculator, exposure limits guide, case study-based solutions guide
http://www.hse.gov.uk/vibration/
• Various powered handtool databases– NIOSH - http://wwwn.cdc.gov/niosh-sound-vibration/
• usage hint - pass mouse/cursor over column headers to read definitions
– Umea Universitat - http://www.vibration.db.umu.se/HavSok.aspx?lang=en
Intervention resources Ergonomics at OSU
• Faculty & Labs
– Engineering Laboratory for Human Factors/Ergonomics/Safety
– Orthopaedics Ergonomics Laboratory
– Spine Research Institute
– Institute for Ergonomics
• Students
– Capstone
– Internships/co-op
– Research practicum, thesis, dissertation
www.ise.osu.edu
Concluding points
• Ergonomics applied in construction - good timing as construction workforce becomes more diverse
• Analyze work as a system of interacting parts, in hazard analysis and in intervention ideation
• Useful information on HAV and WBV is available on the web, through reliable sources
Thank you!
Carolyn Sommerich
Engineering Laboratory for Human Factors/Ergonomics/Safety
The Ohio State University
Email: [email protected]
Call: 614-292-9965