Internattonal Journal of Industrial Ergonomtcs, 9 (1992) 93-95 93 Elsevier

Preface

Shrawan K u m a r

Dept of Phystcal Therapy, Unwerszty of Alberta, Edmonton, Alberta T6G 2G4, Canada

The year 1992 marks the completion of the decade of the disabled. It began with the declara- tion by the United Nations of the year 1981 as the Year of the Disabled. Within this decade considerable changes have occurred. There is generally much greater awareness with signifi- cant, though not enough, positive change in atti- tude compared to the preceding decade. While by some it might be considered only a moral nicety, it is essential that we all wake up to the demo- graphic reality of contemporary society. In the United States it has been reported, as early as 1979 by Grail, that 30% of the population had a varying degree of disability. The baby boom of North America is leading us to a 'grey revolution' in the 21st century. By the year 2010 it is pro- jected that 40% of the entire North American population will be comprised of senior citizens. It has also been shown that aging leads to disability. The United Nations (1990) has reported signifi- cant numbers of disabled people around the world. Thus, the segment of population which has been traditionally ignored from the mainstream ergonomic design considerations is slowly grow- ing to be sizeable. Due to other proposed work place changes such as the 4-day work week cou- pled with a need to produce and compete, a varying degree of integration of the disabled and the senior citizens may move from a moral nicety to an economic necessity. The workplace of today is not equipped to cope with such demographic change. It is, therefore, the purpose of this spe- cial issue to raise some of the pragmatic as well as the technical issues of interaction between rehabilitation and ergonomics.

Rehabilitation and ergonomics at first sight seem very distant from each other. Such a per-

ception is caused by several reasons. First, reha- bilitation deals with sick and hurt people whereas ergonomics is concerned with normal and healthy. Secondly, rehabilitation is practised in hospitals and clinics by medical practitioners whereas er- gonomics is generally practised by non-clinical professionals in industrial settings. Thirdly, reha- bilitation is primarily concerned with factors in- ternal to the patient whereas ergonomics endeav- ors to modify the products, jobs, processes, task design, work station and the like - all being factors external to the worker. However, rehabili- tation and ergonomics are not only very similar in goals (Kumar, 1989), but also built from the same building blocks and use the same or similar pro- cedures to achieve similar goals. Ergonomics, though not a causal factor for any outcome, acts as a modifier. Similarly, rehabilitation strives to achieve a favorable modification in the patient. They are therefore, in concept, content and goals, parallel. This parallelism has been alluded to by Kumar (1989). It is not only these similarities, but also the final goal of enhancing the performance of the patient or the worker by any possible means, which brings them together. Therefore an optimal blending of the two will be of value to both disciplines and significantly enhance both.

The first paper 'Rehabilitation - An er- gonomic dimension' by Kumar presents a view that rehabilitation has a lot to gain from er- gonomics. Further, rehabilitation is one of the remaining responsibilities for ergonomics. He not only presents a case for such integration but also provides a conceptual framework with strategies to realize this goal. In her paper, Nowak presents a practical example of such a concept and methodology. She reports a method for dynamic

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94 Preface

anthropometry and its application, with appropri- ate modification, in rehabilitation. Thus, estab- lished norms could act as reference values against which impairment and recovery both could be compared. Weisman et al. in their article entitled 'Assessing variability in isokinetic strength through a range of motion' report the pattern and magnitude of variation of isokinetic strengths at two lifting velocities and four horizontal dis- tances. They report that the pattern of strength was indpendent of gender and velocity of lift and stayed consistent among subjects. This finding may have an influence on diagnosis and evalua- tion of low-back pain and its management strat- egy.

The next paper emphasizes the preventative aspect of rehabilitation. The maxim 'prevention is better than cure' continues to remain current and valid at all times. If one can eliminate injury and ensuing disability the need for rehabilitation is also eliminated. Though such elimination is not feasible, it is possible to reduce and control mishaps. Chahal et al. have proposed one strat- egy of such a control through development of task-related performance standards.

The next paper by Tsutsumi and Doi on pseudo-3D computer simulation for pathogenesis and rehabilitation of cervical spine deformity in- dicates a useful ergonomically relevant methodol- ogy which can have a meaningful place m rehabil- itation procedure. Such a numerical approach to simulate remodelling or rehabilitation process with appropriate variables may shed light on me- chanical instability and reliable physical perfor- mance.

Manual materials handling, especially lifting, is a common industrial activity. Further it is a known source of injury. Since the mechamcal stress is the primary risk factor, its reliable assessment will lend a higher degree of accuracy to the conclusions drawn from the level of exposure. In their tests, Schippleln and Andersson report a consistency of magnitude in the same subject and consistency of pattern between the subjects. Thus, techniques like this help quantitative assessment of spinal loads in sagitally symmetric actwitles. The study by Moritani et al. reports a s~gmflcant difference in mean frequency power among the patients with low-back pain compared to no pain

condition. Their data suggest that the EMG fre- quency power spectral analysis is a useful tool in objective assessment of low-back muscle disor- ders. If such a disorder begins to set in prior to the injury precipitation It can be used for the purpose of screening and effective intervention.

Porter, in his review paper entitled 'Is hard- work good for the back?' explores the relation- ship between hard work and low back pain. He reports that when exposed to it in early working and adult life, hard work reduces incidence of disc prolapses (slipped discs). However, it may contribute to degenerative diseases. Therefore, an awareness of such a balance between these two outcomes may allow a better reformed deci- sion and an ergonomic strategy for prevention as well as patient management.

The case study by Fenety and Kumar, of an ergonomic survey of a hospital physical therapy department has provided findings of common de- ficiencies in planning and running such facilities. Some practical suggestions and considerations may be of value to enhance efficiency and save costs .

Shein et al., in their paper, provide an overview of human-computer interaction techniques for people with physical disabilities. This area pro- vides a potent methodology to deal with many disabilities and allows a considerably enhanced capability despite remaining disabilities. A suc- cessful environmental modification can be achieved through this means. In the last paper, Shrey and Breslein present industrial rehabilita- tion and disability management issues and trends. They have examined the emergence of proactive multidisciplinary services to control injury and disability.

This issue contains papers with a philosophical and conceptual framework, practical and specific measures (to diagnose, treat or prevent disability), m e t h o d o l o g i e s , s t ra tegies , and t echn ica l knowhows to enable the disabled, and finally a paper with proactive disability management strat- egy. Preparation of this special issue has been a challenge as well as a pleasure.

The special issue editor acknowledges the help of many reviewers in finalizing this issue. They are as follows: G.C. Agarwal, A. Freivalds, V.K. Goel, C.W. Heckathorne, W. Karwowski, A. King,

Preface 95

S. Konz, K.H.E. K r o e m e r , N.A. Langrana , W. Mar ras , A. Mita l , J. Ramsey , M. Singh, G. Smidt , and R.B. Stein.

References

Grail, T B, 1979. A feasibility study of product testing and reporting for handicapped consumers. New York Veteran Admimstratxon

Kumar, S, 1989. Rehablhtatlon and ergonomics Complemen- tary dlSClphnes. Canadian Journal of Rehabdltatlon, 3 99-111

Umted Nations, 1990. Dlsabdlty Statistics Compendmm New York