Ergonomics and quality in paced assembly lines

The aim of this industrial study was to measure relationships between workstation ergonomics and product quality. Quality on two paced manual assembly lines for disposable cameras was measured by the number of defects per week at each workstation. Two ergonomic variables, the time required for the task and the postural deficiencies, were together able to predict over 50% of the quality variance on each assembly line. This study shows the direct effect of ergonomics variables on quality results. © 2001 John Wiley & Sons, Inc.     

Ergonomics research and the disabled

What has ergonomics done to improve the design of products, buildings and environments for handicapped people? The ergonomist, by assisting in the fitting of disabled people to tasks, products and environments designed for people who are not disabled, has made contributions in two main ways. This has been done in the first instance by the adaptation ofexisting facilities and the development of special aids. This is, however, a short-term solution to solve problems that exist now. The ergonomist has also done much to assist in the reduction of handicap for disabled people in the future by taking the capabilities and capacities of disabled people into account when developing new facilities.

The major difficulties which the ergonomist faces in using and applying ergonomics to find generalizable solutions to the problems presented by disability in all its many varied forms are to do with measurement, classification and goals. These difficulties and ways of dealing with them are discussed.     

Ergonomics of the office

The office has.a long history from the monks in their cells copying religious texts through the Victorian office with Dickensian clerks to the paperwork factory of today. Technology has been introduced to help the office cope with a growing mountain of paper, but only seems to have made matters worse. There is much to keep the traditional ergonomist occupied in today' s office in trying to improve the design of equipment, workplaces and working environments. However, the efficient electronic paperwork factory is no longer seen as a desirable objective and more emphasis is now being placed on a systems approach. There is a significant role for the radical ergonomist in this approach to office systems and a number of contributions are outlined. The approach can lead to new models of the office and perhaps also to some unconventional offices     

Ergonomics and lighting

The two main principles of ergonomics can be said to 'fit the job to the man', or 'fit the man to the job'. To a high extent this is really valid for lighting ergonomics. If an employee complains that he (or she) cannot see properly what he is doing in his work it could be adjusted either by improving the job itself or by improving the visual capacity of the person in question (eg, prescribing correct work glasses). If improving measures are not taken local eye discomfort may develop with symptoms as fatigue, ache, pain, burning, pulling, tearing, etc. These symptoms make up a syndrome called asthenopia, otherwise succinctly known as eye strain. The causes of the syndrome can be myriad - but all fall in under the headings 'bad' lighting, 'bad' eyes and 'bad' work.     

Ergonomics around the world-France

The background and history of ergonomics in France is discussed; also the present position of ergonomics in industry, the military, and the universities. The Société d'Ergonomie de Lange Fran?aise is included in the discussion, and finally, future possible contributions of French ergonomics are proposed.     

Ergonomics in the home

The house and housework are as appropriate an area of ergonomics study as in the factory floor, but much less concerted effort has been put into studying the problems of the housewife. It is suggested that investigations to determine the amount of physiological effort (particularly that of muscle activity by techniques such as electromyography), the optimum dimensional accord between equipment and user, and the provision of satisfactory environmental conditions, are needed in order to ensure that the housewife performs her tasks with the minimum of unnecessary effort and maximum satisfaction.     

Ergonomics International

It was the purpose of this study to examine whether replacing long pants (P) with shorts (S) would reduce the heat stress of wearing firefighting protective clothing during exercise in a warm environment. Twenty-four Toronto Firefighters were allocated to one of four groups that performed heavy (H, 4.8?km·h^?1, 5% grade), moderate (M, 4.5?km·h^?1, 2.5% grade), light (L, 4.5?km·h^?1) or very light (VL, 2.5?km·h^?1) exercise while wearing their full protective ensemble and self-contained breathing apparatus. Participants performed a familiarization trial followed by two experimental trials at 35°C and 50% relative humidity wearing either P or S under their protective overpants. Replacing P with S had no impact on the rectal temperature (T_re) or heart rate response during heavy or moderate exercise where exposure times were less than 1?h (40.8?±?5.8 and 53.5?±?9.2?min for H and M, respectively while wearing P, and 43.5?±?5.3 and 54.2?±?8.4?min, respectively while wearing S). In contrast, as exposure times were extended during lighter exercise T_re was reduced by as much as 0.4°C after 80?min of exercise while wearing S. Exposure times were significantly increased from 65.8?±?9.6 and 83.5?±?11.6?min during?L and VL, respectively while wearing P to 73.3?±?8.4 and 97.0?±?12.5?min, respectively while wearing S. It was concluded that replacing P with S under the firefighting protective clothing reduced the heat stress associated with wearing the protective ensemble and extended exposure times approximately 10?–?15% during light exercise. However, during heavier exercise where exposure times were less than 1?h replacing P with S was of little benefit.     

Ergonomics diary

Physiological, perceptual and physical responses to a typical circuit weight-training (CWT) regimen were recorded in two studies. The aims were to assess the intensity of exercise during CWT; and to determine whether physical responses as evaluated by spinal shrinkage were related to physiological and perceptual responses to CWT. In the first study (n = 10) heart rate (HR), oxygen consumption (VO), ventilation (VE), blood lactate (La) and perceived exertion (RPE) were measured in response to CWT. Mean ( ± SD) time to complete three circuits of CWT was 17.8 (± 1-4) min. The HR max, VO₂max and peak La, measured first during an incremental treadmill test, were 195 (±13) beats.min ^?159-7 (±4-8) ml.kg^?1.min^?1 and 14-3 (±3-5) mM respectively. Mean HR and vO₂ during CWT were 69% and 50% of the respective maximal values. The HR-VO₂ ratio observed on the treadmill was elevated during CWT, with VO₂ being lowered relative to HR. Mean VE and La values were 52-7 (± 14-5) l.min^?1 and 6-9 ( ± 3-6) mM. The effect of the same CWT regimen on spinal loading as indicated by change in stature (shrinkage) was investigated in a second study (n = 8). The mean ( ± SD) time taken to complete the circuit was 17-4 ( ± 1-3) min. Mean shrinkage due to CWT (2-5 ± 1 -5?mm) was unrelated to the time taken to complete the circuits, to HR, RPE or to low back pain ratings (p > 0-05). Observations suggest that CWT as represented in these studies engages anaerobic as well as aerobic mechanisms but the exercise intensity may not provide sufficient stimulation for aerobic training. The physical load on the spine indicated by spinal shrinkage was not related to the physiological or perceptual strain.