1 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

2 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 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

3 Maintenance Ability Fig 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

4 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

5 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

6 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 L/min –max frequent 3.8 L/min 180 bpm –compounded by need to disperse heat –no possibility of alleviating load –recommend min ml/min/Kg

7 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 minimum of good or excellent for muscular performance measures –Bench press –Sit up –Squat –Pull up

8 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

9 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…

10 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

11 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

12 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 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

13 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 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

14 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 less dishonest than generally assumed (5%) utilize database correlation to confirm push vs pull, HR response at exertion

15 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

16 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