Faculty Bibliography

This paper describes the application of the ability requirements approach to study the relationship between back injuries and job demands. The procedure used groups of active workers to construct profiles of job demands by rating physical abilities needed to perform various tasks in the job. Environmental demands were similarly rated. Profiles were developed for 25 high injury rate jobs in a mass transit company. Worker ratings of job demands were correlated with back injury rates. The results confirm that back injuries are associated with physical effort or work conditions in some jobs. Several abilities formed a single factor of physical effort while the present inventory of work conditions did not. A multidimensional job description of physical effort, environmental and organizational factors is proposed to explain adequately occupational back injuries in the public transportation, construction and utilities.

The paper describes a knowledge-distribution system that supports decisions on placement of impaired employees. The knowledge base consists of job profiles and medical profiles. The job profiles list tasks and the physical abilities they require. Twenty-one abilities describe the task demands. Active workers rated the exertion, frequency and importance of the physical ability required for each task. Thirty-nine work conditions were rated this way. Using identical scales, experts assessed the impact of impairments on the physical abilities of individuals and the tolerance of work conditions. The screening matches the job profile against the impairment profile. This process has been automated. The program lists tasks and work conditions that may compromise an impaired employee. This information can be used to accommodate employees, restrict duties or design a rehabilitation program. Also, the paper discusses the impact of the system on the operations of medical services within an organization.

Redesigning the job is a strategy for preventing low back injuries at work or for accommodating injured employees who return to work. An evaluation of the physical job demands is necessary in either strategy. Several job demands are associated with low back pain and injury--heavy physical work, static or postural effort, dynamic work-load and exposure to wholebody vibration. Traditional work measurement studies emphasize a rigorous task analysis. By adding biomechanical, physiological and psychophysical measurements, a comprehensive evaluation is possible. There is no standard scheme for a workplace evaluation. The method depends on the end use of the analysis. Job evaluation for workplace design requires an emphasis on equipment and work conditions; evaluation for placement of injured employees should emphasize the operational demands of the tasks. Few studies considered the multifactorial aetiology of low back pain. Most studies that measured the magnitude of biomechanical, physiological and psychophysical stresses attempted to define peak work-loads. The attempt to evaluate the effects of subacute cumulative traumas is only in the beginning. Most ergonomic intervention programmes modify the loads, the design of objects handled, lifting techniques, workplace layout and task design. The effectiveness of these interventions in controlling medical costs or morbidity has not been clearly demonstrated. Consequently, occupational risk factors may be more important for evaluating disability. Job familiarity is the key to effective medical management. Ergonomic analysis procedures may be useful within rehabilitation settings that also provide placement services. The reason is that they facilitate communication between all elements involved in the rehabilitation process. Proper communication procedures are also crucial in implementing ergonomic interventions in the workplace. A health care provider should be part of a task force that oversees these interventions. Future effort should be directed to finding a method that health care practitioners could be competent to carry out effectively in a clinical setting. Expert systems offer promising results in disseminating ergonomic knowledge in primary and secondary health care facilities.