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Ergonomics -Jobs Designed with People in Mind

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What is Ergonomics?

• The size of people - anthropomety

• The strength of people - biomechanics

• The endurance of people - physiology

• The movement of people - kinesiology

• The environment for people - Industrial hygiene

• The information processing of people - Psychology

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What’s the objective?

• Error free performance

– Errors in perceptions

– Errors in decisions

– Errors in actions

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How can problems be identified?

Injury Data

ObservationsInterviews

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What type of injuries are seen?

• Muscle pain• Joint pain• Swelling• Numbness• Restricted motion

• Repetitive stress injury• Repetitive motion

injuries• Cumulative trauma

disorder• Musculoskeletal

disorder

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What’s there usual diagnosis?

• Tendinitis• Rotator cuff tendinitis• Tenosynovitis• Stenosing tenosynovitis• Thoracic outlet

syndrome• Carpal tunnel syndrome

• De Quervain’s • Herniated disc• Tension neck• Epicondylitis• Cubital tunnel• Guyon tunnel• Gangilionic cyst

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What are some common names?

• Trigger finger• Bricklayers shoulder• Carpet layers knee• Pizza cutters wrist• Tailors seat

• Gamekeepers thumb• Cotton twisters hand• Golfers elbow• Tennis elbow

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How are injuries and illnesses calculated?

# of injuries or illnessesTotal hours worked

x 200,000

15 injuries400,000

x 200,000 = 7.5

Fatality1

10

300

600

Lost Time

First Aid

Near Misses

Prevention

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Interviews

• Are there problem jobs??? - ask the

worker

• Structured interviews

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What’s the blueprint for a good ergonomic program?

• Commitment by Top Management

• Employee Involvement

• Written Program

• Review and Evaluation

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What should the program include?

• Worksite analysis

• Hazard prevention and control

• Medical management

• Training and education

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Work site analysis

• Identifies problem areas and risk factors

• Conduct worker surveys

• Perform analysis of tasks and positions that are problems

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Hazard prevention and control

• Prevented by – Design of task, job, or job site

• Corrected by using– Engineering– Work practice– Personal protective equipment– Administrative

• Some more effective than others

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What are some examples of engineering controls?

• Mechanical devices• Lift tables/adjustable workstations• Push/pull carts• Work bins• Tool design• Seating, wrist/foot rest,

glare screens• Floor mats

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What do work practice controls involve?

• Proper work techniques

• Employee conditioning period

• Monitoring

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What are the factors to consider when using PPE?

• Variety of sizes

• Proper fit, and safe design

• Back belts

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Can administrative controls be used instead of engineering controls?

• Considered in conjunction with engineering controls

• Implemented where engineering controls not feasible

• Temporary, does not eliminate hazard

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Examples include!

• Reducing # of repetitions

• Job rotation

• Frequent breaks

• Broadening job content

• Training on proper lifting procedures

• Decrease work pace

• Increase # of employees

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What are the major components of a medical management program?

• Periodic walk-throughs• Symptoms survey• Identification of restricted duty jobs• Health surveillance• Early reporting of symptoms• Medical care• Accurate recordkeeping• Periodic program evaluation

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What training is required?

• General Training

• Job Specific

• Training for supervisors

• Training for managers

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What are the benefits of videotaping a task?

• Record of job

• Offers detailed review

• Allows management to focus on task

JobSafetyAnalysis

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What are the steps to take prior to taping the job?

Observe job

Get permissionPlan the views

Describe job

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How should the job be recorded?

• Use clock, and date

• Shoot upstream and downstream

• Whole body shots

• Zero-in on problems areas

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What additional data should be considered?• Weight of materials• Amount of hand force used• Hand tool or surface vibration• Work organization• Workstation design• Environment - temperature, odors, etc.• Height of worker• Experience of worker and hours at work• Worker modifications - both implemented and

suggested

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Where can I get additional information?

• Trade associations

• Venders

• Visits to other worksites

• OSHA field offices

• OTI

• Internet

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G AL* Find the problem and fix it,

but don’t put Band-Aids on the symptoms!

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Video Display Terminals

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Introduction

• Have revolutionized workplace

• 25% use in 1984, versus 45%in 1993

• More than 18 million workers in jobs

• Along with use comes health effects

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What are the components of a Video Display Terminal?

• Display screen– Shows what’s being processed.

• Keyboard– Allows user to send information.

• Central processing unit– Brains of computer– Performs calculations, organizes data

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What are some of the problems that come with their use?

• Eyestrain and irritation

• Symptoms can be from– improper lighting– glare from screen– poor positioning of screen or copy material

• Adjusting physical and environmental settings

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Fatigue and Musculoskeletal Problems

• Operators are subject to various MSD’s

• Injuries to muscles, joints, tendons, nerves

• Caused/made worse by work related factors

• Early symptoms include:• If workers have problems

PAIN

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Lighting

• Direct so doesn’t shine into screen.

• Four factors must be controlled to avoid eyestrain.– Quantity– Contrast– Direct glare– Reflected glare

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What are some of key areas of work station design?

• Proper design will reduce visual and (MSD) discomfort when the following are observed:– Flexible sitting position

– Support for back, arms, legs, and feet

– Adjustable screens, keyboards, tables, and desks

– Proper chair height, and support for lower back.

– Use of document holders

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How important are Chairs?

• Crucial factor in preventing back pain

• Majority of office workers spend most of time sitting.

• Comfortable for the task.

• Easy adjustments.

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Chair Height

• Human body provides a starting point.

• Height from floor to point at crease behind knee.

• Sole of foot on floor or footrest.

• Allows good circulation

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Seatpan Design

• Size and shape are two factors

• Slightly concave, rounded edge

• Distributes weight/prevents sliding

• Also consider angle.

• Options to include:

– back and forward tilts

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Arm and Backrest

• Armrest, low, short enough to fit under worksurfaces.

• Backrest should support entire back.

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VDT Design

• Separate, adjustable keyboards and screens.

• Top line no higher than user’s eyes.

• Screen and document holder same distance from eye.

– Preferred viewing ranges

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Keyboard

• Detachable and adjustable

• Forearms, parallel to floor, elbows at side

• Wrist in line with the elbows

• Padded and detachable wrist rests

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Mouse

• Operator’s side, arm close to body

• Straight line between hand and

forearm.

• Upper arm not elevated/extended while in use.

• Pad or rest helps maintain straight wrists.

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What are some work practices that may help employees?

• Frequent breaks

• Design jobs so employees can vary VDT task with non-VDT tasks

• Open and positive working relationships

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Back injuries-A painful problem

Ouch !

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What are the risk factors?

• Awkward posture

• Forceful exertions

• Repetitive motion

• Vibration

• Contact stress

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What should I look at when analyzing the job?• Look at the function

• Interview workers

• Break it into elements– work station– work methods

• Use checklist

• Interview supervisors

• Videotape

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What are some of the controls can I use?

• Engineering

• Administrative

• Personal Protective Equipment (PPE)

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Administrative controls!

• Temporary

• Do not eliminate hazard

• Must maintain practices and policies

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Types to consider include!

• More rest breaks

• Job rotation

• Broadening of job content

• Training of proper lifting procedures

• Reduce overtime

• Decrease work pace

• Increase # of employees

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After an injury, how soon should a worker return?

• As soon as possible

• Helps employee/employer

• Reduces cost

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PAIN

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Ouch !

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110300600

FatalityLost Time

First AidNear Misses

Prevention

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