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Assessment of Physical Capacity and Job Demands• Readings - Occupational

Ergonomics Handbook– Ch. 14 Louhevaara

– Ch. 70 Anderson ; Ch. 72 Key

• Outline• Maintaining work ability• Physical job demands and fitness

– firefighters,police, cleaners

• Physical ability testing– Analysis, protocol design

• Assessing Functional capacities– principles

– outcomes

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Job demands and Physical Fitness

• Include physical, mental and social loading factors

• ~20 % of work force in industrialized countries exposed to heavy muscular work– dec in dynamic jobs with simple tools– inc in static, repetitive tasks– Utilize EMG to determine individual

muscle recruitment fig 17.10 Astrand

• when redesign is not feasible, physical fitness becomes important

• secondary preventative measures– individual health promotion– healthy satisfying lifestyle– maintaining work ability / healthy aging– Fitness training– nutrition

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Maintenance Ability• Fig 14-1 - triangle strategy

– work and environment– Organization / Cultural– Individual worker

• Physical Job Demands– categorize workload

• Fig 14-2• heavy dynamic work

– large ms groups - Cardiorespiratory• manual materials handling

– dynamic/static - CV and muscular• static postural work

– lrg and small ms - muscular strain• repetitive work

– small - muscular strain

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Physical work load• Affected by use of strength, frequency of

peak loading, work/rest ratio, environmental factors, intensity

• level of physical strain depends on demand and individual capacity

• optimal / acceptable demand criteria– cardio, muscular and psychosocial

strain– physiological changes– fatigue– specific local changes (small muscles)

• if job demands– do not exceed capacity - adaptation– too high - fatigue, dec productivity– prolonged / repetitive - damage / injury

• Muscular work at the proper intensity, frequency and duration will produce fitness training effects

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Physical Fitness• Fig 14-3 dimensions of Fitness

– CV capacity (aerobic, anaerobic)

– muscular performance

– motor coordination

• based on physiological demands and Anthropometric characteristics– Utilization of capacity requires

voluntary control - therefore all linked to MOTIVATION

– optimal situation - harmony between demand and fitness

• Situation is highly dynamic

• Text looks at specifics of Police, Fire and Professional Cleaners

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Fire Fighters• 200 subjects - job demands of physical

fitness and aerobic power

• muscular performance and motor coordination

• smoke diving with SCBA-– aerobic demand

• clearing passages with heavy manual tools -most muscular demand

• roof operations- motor control demand

• Aerobic Power Demand - Table 14-1

– often 2.1-2.8 L/min

– max frequent 3.8 L/min 180 bpm

– compounded by need to disperse heat

– no possibility of alleviating load

– recommend min 34-45 ml/min/Kg

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Fire Fighters• Muscular Performance

– biomech factors - simulated clearing task - 9 kg power saw - floor to ceiling

– high compression on L5/S1

– ~90 % of isokinetic strength

– back and knee extension

• Table 14.1 - minimum of good or excellent for muscular performance measures– Bench press

– Sit up

– Squat

– Pull up

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Physical Exercise and Fitness

• Physical exercise is one of the basic elements in maintenance of work ability– linked with productivity, quality of

work, absenteeism, and turnover rate– Exercise programs must be tailored to

job demands

• successful intervention requires– commitment and support

• management and staff

– use of work time (for at least part)– feedback and strong motivation– positive experience with exercise– skill full instruction– confidential, voluntary and no guilt

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Assessment of Physical job demands

• Prior to recommending physical exercise programming (specificity)

• it is important to perform an assessment of physical job demands (job analysis)– Job load and hazard analysis– Measurement of heart rate– Estimation of energy expenditure– Rating of overall perceived exertion– Rating of local perceived exertion

• Back, arms…

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Physical Ability Testing• Ch 70 - Anderson• Ergonomics - alter the demands of

the job to match the worker-redesign• Alternative approach is to match

workers to the job, based on physical abilities– decline of 20-40% in injury rates when

physical ability testing is implemented

• Effectiveness depends on ability of test battery assess what it intends

• requires – thorough job analysis– carefully chosen tests– validation that test predicts

performance on the job

• courts prefer testing to be focused on ability to perform not injury risk

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Job Analysis• Identify essential function of the job

– functions that define purpose of job

• cost / benefit analysis– cost of not being able to perform task– probability of individual lacking ability– balance with cost of testing applicants– Would it be better to redesign job?

• Test Battery Design– test required to have a high degree of

relatedness to essential function– Use realistic cutoff scores and

normative data– accurate - precisely measures attribute it says

it measures

– reliable - yields same results• over time and by different testers• objective rather than subjective tests

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Validation• Statistical validation

– prospective - test individual applicants - do not use results in hiring - analyze performance of all individuals hired

• productivity, retention, injury rate, supervisor evaluation

– Compare to test results

• Fig 70-1 - injury rate twice as high in those who failed screening test

• or implement test in hiring practice, and compare to those hired previously– lack of control for other factors

• All applicants must be treated fairly– all must be tested - same preparation

– same re-testing procedures

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Assessment of Worker Capacities

• Workers’ compensation costs can be very high

• Knowledge of worker functional capacities important to reduce these costs

• Knowing capacity is important for;– decision to hire– decision to return to work

• Fig 72-1 - Key• FCA - Functional Capacity Assessment

– return to work testing process– individual physical functional work

related capability– confirmation of meeting or not meeting

minimum physical requirements

• goal of FCA is return to work ASAP– even if at limited capacity, some pain

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Job Placement Assessment(JPA)

• Provides data prior to hiring– assists managers - reduce injuries

• JPA - specific, objective, standardized protocols accurate and repeatable– Identify employees capability for

lifting, carrying, pushing, pulling…

• Goal -accurately match worker with job

• Components of assessment fig 72-2– weighted capabilities -CV, posture

– tolerance and endurance capabilities• establish safe limits for work day

– Validity of participant - honesty– fig 72-3 - less dishonest than generally

assumed (5%)• utilize database correlation to confirm• push vs pull, HR response at exertion

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Worker Assessment Principles

• Principles for selecting FCA– must contain standards for identifying

validity of participation

– methodology must be consistent

– utilize standard equipment

– administrators must be trained and objective

– processing of results must be standardized

• Fig 72-5 – reports should compare results with

demands of job

– unbiased and defendable decision about return to work

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Outcomes• Primarily - dec re-injury rates

– dec lapse of time before return to work

– dec incidents and costs

• JPA • eg fig 72-6 paper manufacturer

– pre and post JPA implementation

• Fig 72-7, 72-8 – possible decision pathways once

information is available

• Diversification - Inc utilization and effectiveness– mobile assessment

– onsite services