Assessment of Physical Capacity and Job Demands

1. Assessment of Physical Capacity and Job Demands • Occupational Ergonomics Handbook • Ch. 14 Louhevaara • Ch. 70 Anderson • Ch. 72 Key

2. Outline • Physical job demands and fitness • firefighters, police, cleaners • Physical ability testing • analysis, protocol design • Assessing functional capacities • principles • outcomes

3. Job Demands and Physical Fitness • Job demands include: • physical, mental and social loading factors • ~20 % of work force in industrialized countries exposed to heavy muscular work. •  in dynamic jobs with simple tools •  in static, repetitive tasks

4. When job redesign is not feasible, physical fitness becomes important. • Control measures affecting muscular work performance through fitness are called secondary preventative measures: • individual health promotion • healthy satisfying lifestyle • maintaining work ability / healthy aging • fitness training • nutrition

5. Triangle strategy for maintenance of worker ability (fig. 14.1): • work and environment • ergonomics, safety, hygiene • organizational culture • psychosocial, management issues • individual worker • fitness, satisfying lifestyle

6. Physical Job Demands • Physical job demands can be classified as: 1.Heavy dynamic work (forestry, police, firefighters) • large muscle groups • cardiorespiratory strain •  with PPE 2. Manual materials handling (MMH) (factory, building) • dynamic/static work with large muscle groups • CV and muscular strain 3. Static postural work (electrical assembly) • large and small muscle groups (musculoskeletal strain) 4. Repetitive work (secretary) • small muscle groups (musculoskeletal strain)

7. Physical work load is affected by use of strength, frequency of peak loads, work/rest cycles, environmental factors and work intensity. • The level of physical strain depends on job demands and individual capacity. • Acceptable physical job demands for different types of work depends on: • cardiovascular strain • musculoskeletal strain • psychosocial strain

8. Acceptable job demands arises from the principle that there are individual differences for physical strain. • When physical job demands: • do not exceed capacity: adaptation (fast recovery) • too high: fatigue,  productivity (slow recovery) • prolonged / repetitive: injury/disease • Muscular work at the proper intensity, frequency and duration will produce fitness training effects.

9. Physical Fitness • Dimensions of fitness (fig 14.3) • CV capacity (aerobic, anaerobic) • muscular performance (strength and endurance) • motor coordination (flexibility, balance) • motivation • Physical work capacity is based on physical fitness. • if the worker’s fitness and anthropometrics are in harmony with physical job demands the situation is acceptable • this situation is highly dynamic

10. Fire Fighters • Lusa et. al 1994: • 200 subjects rated task demands for aerobic power, muscular performance and motor coordination • smoke diving with SCBA had greatest aerobic demand • clearing passages with heavy manual tools had the greatest muscular demand • roof operations require high motor control demand

11. Aerobic Power Demand (Table 14.1) • common tasks require 2.1 - 2.8 L/min • work rates often reach 3.8 L/min • heart rates reach near maximal levels • compounded by heat stress • researchers recommend min 34-45 ml/min/kg • Fire fighter job demands can be extremely high, and place a serious cardiovascular strain on older individuals.

12. Muscular Performance • biomechanical factors were evaluated • simulated clearing task, 9 kg power saw - floor to ceiling • high compression on L5/S1 (6228 N) • Minimum muscular performance values (Table 14.1). • Bench Press • Sit-up • Squat • Pull-up

13. Police Officers • Hard to alter job demands. • The majority of work time can be sedentary. • There are unexpected peak load situations. • Many police officers become sedentary in middle age. • With an intensive fitness training program, officers reduced cardiovascular risk factors and  aerobic and muscular fitness. • Good selection criteria will guarantee an acceptable level of fitness for new officers. • After age 35 fitness should be tested regularly.

14. Professional Cleaners • Very common physically demanding occupation. • The mean age is older than other professions. • Requires aerobic capacity, muscular performance and motor coordination. • Fitness level needs to be higher than average age-related values. • Physical fitness training will improve performance.

15. Physical Exercise and Fitness • Physical exercise is essential for sustaining aerobic and muscular fitness, and is linked with good work performance regardless of the type of work. • Exercise has a positive effect on productivity, quality of work, absenteeism, and turnover rate. • A high level of physical fitness is important in sedentary jobs as it has a positive influence on mood. • Thus exercise is a basic element in the maintenance of work ability. • Physical exercise must be tailored to actual job demands.

16. Before starting physical exercise it is important to perform an assessment of physical job demands: • 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)

17. Successful work-site physical exercise interventions require: • commitment and support of management • commitment of the work unit • exercise during work time • feedback and strong motivation • positive experience with exercise • skillfull instruction • confidential, voluntary and no guilt

18. Physical Ability Testing • Ch 70 - Anderson • Ergonomics attempts to alter the demands of the job to match the capabilities of the worker. • An alternative approach is to match workers to the job, based on physical abilities. • Several studies have documented the importance of physical ability testing. • Injury rates  20-40% when physical ability testing is implemented.

19. The effectiveness of physical ability tests mainly depends on the ability of the test battery to assess what it intends.This requires: • a thorough job analysis • carefully chosen tests • validation that test predicts performance • Courts prefer that the emphasis be on the ability to perform the job rather than the risk of injury.

20. Job Analysis • Identify the essential functions of the job. • usually the functions performed most frequently • infrequent function may also be essential • Cost / benefit analysis • if everyone can pass the test, why bother • cost of not being able to perform task • probability of individual lacking ability • balance with cost of testing applicants • Can a job function that is difficult to do be modified through ergonomics.

21. Test Battery Design • Test required to have a high degree of job-relatedness to the 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 • Safe: reduce the risk of injury.

22. Validation • Statistical validation • prospective statistical analysis • test individuals when hired then track performance over career • measure productivity, retention, injury rate, supervisor evaluation • compare performance with test results • Content validation • demonstrate that the content of the job is reflected in the content of the test battery

23. Ongoing Practices • Four aspects are crucial to assure that the test battery is fair to all applicants. 1. All applicants must be treated fairly. • same conditions 2. Same scoring process for everyone. 3. Same re-testing procedures 4. Take prior experience into consideration.

24. Assessment of Worker Capacities • Chapt. 72 Key • Workers’ compensation costs can be staggering. • Knowledge of worker functional capacities is important for reducing workers’ compensation costs. • It is critical to know physical work capacity. • decision to hire • decision to return to work

25. Functional Capacity Assessment(FCA) • return to work testing process that determines an individual’s physical functional work related capability • confirmation of meeting or not meeting minimum physical requirements • The goal of FCA is return to work ASAP. • even if at limited capacity, some pain

26. Job Placement Assessment • Provides data prior to hiring • assists managers in making decisions • potential to reduce future injuries • JPA: specific, objective, standardized protocols followed to allow for accurate and repeatable results. • Identify an employees ability to: lift, carry, push, pull and do other job specific activities. • Goal: accurately match worker with job to increase productivity.

27. Components of Assessment • Weighted capabilities • ability to perform a specific task • CV, posture • Tolerance and endurance parameters • sitting standing and workday tolerance • establish safe limits for work day • Validity of participant • determine if someone is being dishonest • less than we generally think (5%)

28. 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 • Assessment reports should compare results with the demands of job. • unbiased and defendable decision about return to work

29. The Provider • The provider of worker assessments are instrumental in  return to work percentages. • Physical and occupational therapists are the primary providers of worker assessments. • The therapist needs to provide objective, unbiased data.

30. Outcomes • The primary outcomes of worker assessments: •  reinjury rates •  lapse of time before return to work •  incidents and cost of litigation • JPA can be very effective • fig 72-6: paper manufacturer • 70 employees • went from 530 to 28 lost work days • company saved $2,000,000

31. Mobile assessments are cost effective and convenient for the employer and employee. • Large trucks can be used for mobile occupational health clinics. • convenient for remote sites • An onsite industrial therapist can be a very cost-effective way for a company to meet its needs. •  down time • prompt treatment