design error most people look like this... some designers think that people look like this
TRANSCRIPT
Design Error
Most people look like this...
Some designers think that people look like this...
What is Ergonomics?
The study of man's relationship with his workplace.
Fitting the task to the man rather than forcing him/her to adapt to his working environment.
Designing the workplace to prevent occupational injury and illness.
Discovering the capabilities and limitations of the human body.
Balance for Optimization
Ergonomics
WorkerCapabilities
JobDemands
CUMULATIVE TRAUMA DISORDERS (CTDs)
Term assigned to identify a group of injuries that classically result from
long-term and repeated “wear and tear” on the musculoskeletal system.
• CUMULATIVE indicates injuries that develop gradually over time, and result from many repeated stresses on a particular body part.
• TRAUMA signifies bodily insult or injury from mechanical stresses.
• DISORDERS describes the adverse health effects that arise from chronic exposure to repeated trauma.
Ergonomics
Cumulative Trauma DisordersYour Job
Your Body
Trauma
Healing Valve
Your Job
Your Body
Trauma
Healing Valve
CTD
Cumulative Trauma Disorders
Win - WinProduction
Quality
Compliance
Compensation Costs
Healthy Workforce
Careers/Employment
Safety Working Conditions
Ergonomics
OSHAct 1970"General Duty
Clause"
Section 5. (a) Each employer -
(1) shall furnish to each of his employeesemployment and a place of employment whichare free from recognized hazards that arecausing or are likely to cause death orserious physical harm to his employees;
DUTIES
Ergonomics
Voluntary Guidelines
o OSHA Meatpacking Guidelines
o General Industry Guidelines (dropped in lieu of standard)
o Food Distribution Warehouses
o ANSI HFS-100/1988; VDTs
o ANSI Z-365; Control of CTDs
Ergonomics
Nature of Injury
Strains/Sprains 43%
CTDs 5%
Occ Illness 4%
Laceration/Puncture11%
Fractures 9%
F.B. in Eye 3%Dislocations 2%
Contusions 9%Burns 3%
Amputations 1%
1990 Ohio Injury/Illness Claims Information1990 Ohio Injury/Illness Claims Information
Ergonomics
Part of Body
Back 20%
Face/Neck 3%
Trunk/Internal 11%
Arms 12%Hands 5%
Fingers 11%
Legs 13%
Feet/Toes 5%
Mult/Major 13%
Other 15% Eyes 4%Head 2%
1990 Ohio Injury/Illness Claims Information1990 Ohio Injury/Illness Claims Information
Ergonomics
CTD Recognition Rising
0
2000
4000
6000
8000
10000
12000
14000
1985 1986 1987 1988 1989 1990
Occ Illness CTD
In 1990, 59% of all Occupational IllnessClaims are logged asCTDs
In 1990, 59% of all Occupational IllnessClaims are logged asCTDs
One half of all CTD claims are logged asCarpal Tunnel Syndrome (CTS)
One half of all CTD claims are logged asCarpal Tunnel Syndrome (CTS)
Ergonomics
Ohio Back Injury Claims
0
5000
10000
15000
20000
25000
30000
79 80 81 82 83 84 85 86 87 88 89 90
Low Back Back General Back w/Disc
In 1990, $513 Mwas paid out bythe BWC for back injuries alone
In 1990, $513 Mwas paid out bythe BWC for back injuries alone
Ergonomics
Average Total Claim Cost
$0 $2 $4 $6 $8 $10 $12 $14 $16 $18 $20
Eyes
Head
Face & Neck
Back
Trunk +
Arms
Hands
Fingers
Legs
Feet/Toes
$5
$18
$8
$18
$12
$7
$5
$4
$9
$5
(Thousands)
Direct Costs = Medical + Comp + Reserve
Direct Costs = Medical + Comp + Reserve
Indirect costs are estimatedanywhere from 4 up to 20 times direct costs
Indirect costs are estimatedanywhere from 4 up to 20 times direct costs
1980-1983BWC data
1980-1983BWC data
Ergonomics
Iceberg Analogy
Accident Cost
•Medical Payments•Compensation
Supervisor time to investigate
Breaking in substitute
Efficiency due tobreak-up of crew
Damaged tools/equipment
Down-timeOverhead $ while work disrupted
Failure to meet deadline/fill orders
Loss of production
Loss of good will
Overtime to make up production
Hiring costs
Lost time by fellow workers
Direct Costs
Indirect or HiddenCosts
Worksite AnalysisKey Elements
I. Records Analysis I. Records Analysis
Worksite Analysis
Records Analyses help identify & prioritize jobs to evaluate.Records Analyses help identify & prioritize jobs to evaluate.
Accident Production Personnel Employer/Employee Records Records Records Survey
OSHA log 200 Seasonal Trends Turn-over Rate Symptoms surveyIncidence Rate Quality Control Absenteeism Early reporting mechanismPrevalence Rate Model Changes Suggestion award programFirst-aid logs BottlenecksAccident Invest.Workers’ Comp.
Worksite AnalysisKey Elements
I. Records Analysis
II. Risk Factor RecognitionII. Risk Factor Recognition
OCCUPATIONAL
RISK FACTORS
OCCUPATIONAL
RISK FACTORS Attributes of a job or task that we know increase the probability of developing a musculoskeletal cumulative trauma disorder (CTD)
• FORCE (Internal & External)
• POSTURE
• REPETITION
• INSUFFICIENT REST
Worksite Analysis
OCCUPATIONAL
RISK FACTORS
OCCUPATIONAL
RISK FACTORS Attributes of a job or task that we know increase the probability of developing a musculoskeletal cumulative trauma disorder (CTD)
• FORCE (Internal & External)
• POSTURE
• REPETITION
• INSUFFICIENT REST
Worksite Analysis
Synovial Sheaths
Carpal Ligament(Extensor Retinaculum)
Extensor Tendons
TWO KINDS OF BACK INJURIES
MUSCULAR SPINAL
Resting Dynamic Static
bloodflow
needed
bloodflow
supplied
bloodflow
needed
bloodflow
needed
bloodflow
supplied
bloodflow
supplied
Vertebrae
Top View
Side View
Micro-fractures in Vertebral Endplate
Scar tissue from healing fractureshinders passage of nutrients to disc resulting in gradual weakeningand de-generation.
Disc Degeneration
Hierarchy of Controls
Ergonomics
Engineering ControlsWorkstation DesignTool DesignProcess ModificationMechanical Assist Administrative Controls
TrainingJob RotationPacingPolicyJob Enlargement
Personal Protective EquipmentGlovesWrapsShields
FIRST CHOICE
SecondChoice
Last & Least
BACK INJURIES
MAN VS. MACHINE
•DECISION MAKING•LOW REPETITION ACTIVITIES•LOW FORCE APPLICATION•DELICATE FORCE APPLICATION
•TAKING INSTRUCTION•HIGH REPETITION ACTIVITIES•HIGH FORCE APPLICATION•HAZARDOUS ENVIRONMENTS
STATURE
EYE
SHOULDER
ELBOW
HIP
KNEE
21.67”21.5”19.3”20.0”
N.A.E.A.
L.A.
36.0”36.4”32.7”34.0”
N.A.E.A.
L.A.
43.5”43.3”40.8”40.9”
N.A.E.A.
L.A.
N.A.E.A.
L.A.
69.1”68.6”65.2”65.1”
N.A.E.A.
L.A.
64.6”64.4”60.7”60.9”
N.A.E.A.
L.A.
56.7”56.5”52.8”53.2”
N.A.= NORTH AMERICA E.= EUROPE A.= ASIA L.A.= LATIN AMERICA
50thPERCENTILE
MALE
D
E
C
B
A
Horizontal Work Envelope
A-Normal reach radiusB-Sitting/Standing distanceC-Extended reach radiusD-Beginning work distanceE-Optimum work area
Max = 15”Max = 9”Max = 22”Ideal = 4”10” x 10”
SIT OR STAND?Type of Task
Lifting more than 11lbs
Work below elbow height
(e.g. packaging or assembly)
Extended horizontal reaching
Light assembly with repetitive movements
Fine manipulation and precision tasks
visual inspection and monitoring
Frequent moving around
First Choice
Standing
Standing
Standing
Sitting
Sitting
Sitting
Sit-Standing
Second Choice
Sit-Standing
Sit-Standing
Sit-Standing
Sit-Standing
Sit-Standing
Sit-Standing
Standing
A > 4” B = (for power grips) 1.5” C = 3” to 3.5” (for precision operations) .45”
Manual Tool Dimensions