Discomfort in the use of personal protective devices (PPD) has been one of the chief causes of their non-use. A field trial using industrial helmets was carried out to ascertain whether by training and repeated wearing subjects could experience a significant adaptation to discomfort. Ten subjects took part in the trial in a tropical environment by wearing helmets repeatedly (6 h a day) for one month. Subjective evaluations of discomfort were made at the end of the 1st, 3rd, 5th, 14th and 30th day. It was revealed that complaints of discomfort, viz. hotness, heaviness, bad fit, etc., decreased markedly throughout the 30 day period. Though positive responses of adaptation to discomfort seem to reach an optimum towards 30 days, it is difficult to draw any conclusions on the optimum period of adaptation for each discomfort factor. In relation to inherent discomforts that are extremely difficult to overcome without compromising the protection efficiency of a PPD, the principle of adaptation seems to be a very important facet which has to be developed for an effective PPD programme.
Due to the large variability in heads and faces in one population, the standard anthropometric dimensions of the head, measured from anatomical landmarks alone, may not suffice for the design of fitting headgear, e.g., helmets. To provide adequate data of the shapes and contours of the head to the designer, appropriate head models sculptured using comprehensive head dimensions, must be developed. This paper describes (a) a procedure of collecting comprehensive anthropometric data of the head using a photogrammetric method and (b) a simple sculpturing technique to reconstruct a head model of the user population
The Industrially Developing Countries (IDC) today, to a great extent, depend on Industrialized Countries (IC) for the supply of most industrial goods. An attempt has been made to ascertain the degree of design incompatibility experienced by users of these imported goods due to differences in the body sizes of people in producer and user countries. A comparative study of variations in body sizes is made from data available in literature and from anthropometric surveys. The results reveal differences in almost every part of the human body. The need for reliable anthropometric data in respect of IDC is stressed. Urgent measures are required to introduce changes in equipment, particularly for the benefit of users in IDC.
The suitability and effectiveness of four different types of British made respirators were studied with respect to comfort, convenience and fit on wearers in Sri Lanka (a developing country). Objective and subjective assessments were made to evaluate the degree of discomfort and interferences to the use of senses. The study revealed that factors such as breathing resistance, work-rate and activity period affected the physiological responses. The weight of the respirator and the skin temperature had no direct relationship with the cardiovascular stress. Positive-pressure respirators that gave lower face temperatures than negative-pressure masks gave this type of respirator an additional advantage in hot environments. Respirators that restricted jaw movement affected the speech intelligibility of the wearer. Orinasal masks restricted vision more than the other types. The problem of fit was found negligible though head and face dimensions significantly differed between the British and the Sri Lankans. Subjective assessment correlated well with objective tests.
Hotness, weight, fitting problems etc., have been found to be the chief causes of the unpopularity of industrial safety helmets in tropical environments in developing countries (DC). Some selected safety helmets manufactured in industrialized countries (IC) were modified to provide extra head ventilation and to reduce weight, in order to make them more acceptable to users in hot environments. The modified helmets were subjected to ergonomics evaluation both objectively and subjectively in the laboratory (in simulated tropical conditions) as well as in the field situation. There was evidence that white helmets had some advantages in comfort, viz. reduction of hotness, compared to the other colours, e.g. red, green etc., when worn in the presence of radiant heat in the laboratory. Ventilation holes provided at the top of the shell seemed to reduce the greenhouse effect within the helmet shell which therefore felt less uncomfortable than a fully covered helmet. Even with a small reduction of weight, such as 45 g in helmets weighing about 350g, the difference in weight was perceived by the wearers. In adapting helmets made in IC for use in tropical climates, head ventilation and low weight perception are important aspects in comfort which need to be considered. In addition to low cost, a harness material suitable for sweat absorption is required. Adjustability and sizing to fit 90% of the user population also needs to be considered in the design and manufacture of safety helmets for people in DC.
It is beyond doubt that high technology has elevated the standards of living of mankind. The modern technology created and developed to a great extent by Western or developed societies is now in great demand in Eastern and developing societies who are trying to leap-frog towards advancement. But unfortunately, in the transfer of technology, both the giver and the receiver seem to make many mistakes. A technology transferred without considering the ethnic variables in the societies and differences in the climates, has found to cause problems to the acquirer. Due to the basic human factor differences such as sizes of people, physical environment, physical capacities and organizational and cultural differences, a technology which is unadapted has found to be inappropriate, harmful, hazardous and unsuccessful. In the areas of health, working conditions, production and finance, undesirable effects have resulted through haphazard technology transfer, For a successful transfer, it is therefore stressed that technology has to be adapted or modified taking into consideration the technological, anthropological and socio-economic factors of the acquiring population
Asia has more than a half of the world population. However, ergonomics has not been widely applied with exceptions of Japan and Korea. Recently, the excitement of ergonomics is being spread to other countries such as Hong Kong, Taiwan, and Indonesia. Although there have been two regional conferences, PPCOE and SEA Conference, Asian ergonomists have not met together to discuss their activities in a world conference. Therefore, the objectives of this symposium is to provide the opportunities for them to discuss the current status of ergonomics and possibly joints efforts to promote ergonomics in Asia. At the same time, this symposium intends to introduce the ergonomics activities in Asia to Western and non-Asian ergonomists and to look for new guidance to enhance its activities from the world renowned exports who have experienced in working in Asia with Asian ergonomists. This syposium consists of two sessions: one panel session and one technical session
The evaluation of human individual characteristics is very important for any ergotechnical system optimization, especially in occupational safety. Investigations were carried out for this purpose. An important classification of ergonomic characteristics for construction workers was prepared. The importance and relevance of the choice of those characteristics as well as their application are presented in the article.
Ergonomics or human factors, as an applied science concerning the design of interfaces between man, machine and the working environment, has shown its great capacities and potentials for improving working conditions and efficiency during its applications in most industrially developed countries (IC). As a means of improving the economy, industrialisation has been initiated in many industrially developing countries (DC). Knowledge and technology available in ICs have been transferred to DCs in order to increase the process of industrialisation. Ergonomics as a western discipline has also been transferred to many DCs during the technology transfer process. As an example of the transfer and development of ergonomics in industrially developing countries, this paper examines the development of ergonomics and its various areas of application in the People's Republic of China. After reviewing the current ergonomics situation and its applications in China from various points of view - i e, from organisation, research, education and industrial application - promises and problems associatd with the development of this new area of science are discussed.
Ergonomic improvements of work station design have been widely embraced as a measure for reduction of physical work load (mechanical exposure) and prevention or control of occupational shoulder-neck disorders. However, other elements of work rationalization, more in the hands of production engineers, may also influence the mechanical exposure. The present study concerns shoulder-neck exposure in a Chinese and a Swedish assembly line workplace. Interactive effects of ergonomic work station design, and production engineering (in terms of assembly line balancing and sensitivity of assembly line layout to production irregularities) on shoulder-neck exposure have been studied. It was shown that the Swedish workplace has a better ergonomic work station design, reflected in more favorable work postures during assembly operations. At the same time, the Swedish assembly line is better balanced and less sensitive to production irregularities, which probably reduces the total duration of idle time during assembly compared with the Chinese line. On the Swedish assembly line, arm movements are more frequent, and trapezius and infraspinatus muscle activation is more repetitive. Muscle activation levels are similar on the two lines. However, a larger proportion of low level muscle activities were found on the Chinese line compared with the Swedish line. On the basis of these results, it is suggested that the mechanical exposure of the assembly workers is a result of counteracting effects of improved ergonomic design of work stations and more effective production engineering.
This paper presents 2 musculoskeletal disorders questionnaire surveys in 10 different Chinese occupational groups. Data collected from 1,603 workers using a modified Nordic musculoskeletal disorders symptom questionnaire showed that the 12-month prevalence of musculoskeletal disorders, particularly in the low back and shoulder-neck regions, was high at many Chinese workplaces. Significant differences existed between occupational groups. Assembly workers usually had higher neck-shoulder complaints compared to workers in most other occupations. However, the nature of assembly seemed also to influence the prevalence rate. Workers at a cassette recorder and a TV set assembly plant appeared to have more neck complaints compared with a group of thermos flask assemblers.
This paper presents the results of an ergonomics survey in four different Japanese work places. The survey consisted of two parts. In the first part, the physical and psycho-social problems of the female workers were investigated. Questionnaire techniques were used to assess musculoskeletal disorders in various parts of the body and of psycho-social stress at work as well as in the daily life situation. Furthermore, work posture analysis, task analysis, simple clinical tests and flexibility tests were conducted. In the second part, the ergonomics intervention practices in different types of Japanese work places were examined. Three different questionnaires were developed and used to collect information from representatives of employees, management and responsible governmental agents of the Department of Industrial Safety and Health, Ministry of Labor, with regard to ergonomic interventions at work places. Management, employees, and government representatives expressed desire for cooperation and participation for arrangement of the ergonomics intervention program. A model for appropriate ergonomics intervention in industry is developed with regard to physical and psycho-social problems at work. Factors influencing worker participation and the establishment of a dynamic system of ergonomics intervention at work places are discussed. Practical ways for improving the working conditions of female workers are: (i) cooperation between managers, workers, and government officers is regarded as vital for the ergonomics intervention program, (ii) worker participation, (iii) appropriate training course with regard to ergonomics education, and (iv) managerial support
In industrial work, working postures play an important role, separately and combined with other strain factors. The combined effects may be worse than those of single factors. The purpose of this investigation was to compare the body size, work postures and musculoskeletal discomforts between a group of female workers in a pharmaceutical plant and another group in a textile plant. Two hundred workers have participated in the following studies; (i) measuring anthropometric data in the standing and sitting positions, (ii) using the Ovako Working Posture Analysis System (OWAS), and (iii) using the detail Standardized Nordic Questionnaire for analyzing the musculoskeletal troubles in different parts of the body. The investigation has identified five main factors associated with the musculoskeletal discomforts: (i) lack of worker selection and lack of appropriate training to prevent occupational hazards or work-related diseases, (ii) poor ergonomic design of the work place and task including work organization, (iii) poor working postures, (iv) lack of task variation, and (v) insufficient rest breaks. These could be improved by introducing ergonomic interventions for both adjusting the individual work places and the task performed. It is necessary to consider preventive measures for musculoskeletal disorders, especially for female workers in industrially developing countries. Ergonomic aspects of the preventive measures should include: (a) consideration of appropriate worker selection for various works with sufficient training and instruction, (b) ergonomic redesign of work places, and (c) ergonomic considerations in work organization.
Subjective feeling of general fatigue and physiological strain were studied in one hundred female professional employees of industrial worker and full-time nurses. Using an interview questionnaire the feeling of fatigue were studied. The subjects were asked to indicate on the body diagram all the areas of musculoskeletal pain from which they perceived discomfort. Furthermore physical strength test consisting of grip test, back and leg strength test were carried out before and after work on all subjects. The results indicated that the two groups of employees showed different symptoms of "pain" and/or "fatigue," with regard to the different parts of body. It was also noted that the physical strength after work was lower for both groups as compared to before work and even lower for the industrial workers than the nurses. The feeling of fatigue between the two investigated groups was not significantly different, but for the musculoskeletal pain was highly significantly different. The worker group used also more pain-killing drugs for releasing the muscle pain. It was evident that ergonomics intervention for female professional workers was of great importance and urgency, particularly for making the workplace more human. Improvement of the working conditions, better organization of work, and ergonomics interventions are suggested as necessary measures for reduction of pain and feeling of discomfort
An ergonomics survey was carried out using interviews based on Standardized Nordic Questionnaires for evaluating musculoskeletal disorders of 1,000 female workers in five different industries in Thailand, viz. garment, fertilizer, pharmaceutical, textile, and cigarette. A checklist used in an ILO study for examining ergonomics problems was used for identifying ergonomics problems. The results show that about 50% of the female workers experienced a high prevalence of musculoskeletal symptoms in their lower backs, particularly the textile workers. The musculoskeletal symptoms of each body region were significant in each industry during the last year and the preceding 7 days (p < 0.05). Other ergonomics problems in the survey industries included heavy manual handling, prolonged sitting and standing, awkward work postures, poor machine design and operation, high repetitive and monotonous movements, poor work organization, and unsatisfactory working environments. Based on the results of this survey, it became obvious that ergonomics problems related to occupational health and safety of female workers seem to fall into three categories: (i) poor working practices and workplace programmes without sufficient knowledge of ergonomics principles, (ii) lack of adjustment to local population of imported machinery and equipment and their use, and (iii) lack of appropriate work organization. The findings demonstrate the need and the importance for ergonomics intervention in industrially developing country using low-cost improvements and appropriate training methods. It also indicates that research in ergonomics applications is needed, considering the specific characteristics of the industrially developing country.
Hearing loss induced in thirty female workers because of exposure to continuous noise was studied in a plastic bag plant in Samutprakarn Province, the largest industrial zone in Thailand. The sound level in this plant was 98.5 dBA., 94.0 dBA. and 93.0 dBA. in the weaving, winding and warping sections, respectively. Results of an audiometric test showed a significant relationship between high noise level and hearing loss at frequency 4,000 Hz. A questionnaire survey found that a relatively high number of workers had various symptoms such as: 76.7% general fatigue, 70% headache, 63.3% ear distension and 56.7% vertigo. Concerning the usage of ear protective devices, it was found that 80% of the workers have never used such devices, 16.7% occasionally used them, and 3.3% have always used cotton wool to reduce the high noise level. Their reasons for non-use of ear protective devices were 1) not provided by the employer (86.7%), 2) not necessary (83.3%), 3) accustomed to the noise (63.3%), 4) nobody uses (56.7%), and 5) no loud noise (16.7%). These results point to the need for improving the work conditions and welfare services of the workers at this plant. Also, hearing conservation programmes can be instituted in developing countries through cooperation among the safety inspectorate, the employer and the workers.
Carpet weavers suffer from musculoskeletal problems mainly attributed to poor working postures. Their posture is mostly constrained by the design of workstations. This study was conducted to investigate the effects of 2 design parameters (weaving height and seat type) on postural variables and subjective experience, and to develop guidelines for workstation adjustments. At an experimental workstation, 30 professional weavers worked in 9 different conditions. Working posture and weavers' perceptions were measured. It was shown that head, neck and shoulder postures were influenced by weaving height. Both design parameters influenced trunk and elbows postures. The determinant factor for weavers' perception on the neck, shoulders and elbows was found to be weaving height, and on the back and knees it was seat type. Based on the results, the following guidelines were developed: (a) weaving height should be adjusted to 20 cm above elbow height; (b) a 10º forward-sloping high seat is to be used at weaving workstations.
Carpet weaving is a high risk occupation for developing musculoskeletal disorders (MSDs). The objectives of the present study, which was carried out in the Iranian hand-woven carpet industry, were determination of the prevalence of MSD symptoms, identification of major factors associated with MSD symptoms and development of guidelines for workstation design. 1,439 randomly selected weavers participated in this study. A questionnaire was used to collect data on MSD symptoms. The results revealed that the prevalence rates for symptoms in different body regions were high as compared to the general Iranian population (for neck, back and large joints, both p < .0001). The results of multivariate analyses showed that major ergonomic factors associated with musculoskeletal symptoms were loom type, working posture, daily working time and seat type. Based on the results, some general guidelines for designing weaving workstations were developed. A prototype test showed that the new workstation was acceptable for subject tests and that it improved working posture.
This paper reviews the role and importance of small-scale industries together with the issue of occupational health problems and their causes in Iranian hand-woven carpet industry as a typical informal small-scale industry in an industrially developing country. The objective of this paper is to review health risk factors and related occupational health and ergonomic problems in the carpet industry. Since the overwhelming majority of weavers' health problems originate from ergonomic risk factors, it is concluded that any improvement program in this industry should focus on ergonomic aspects. To assess ergonomic conditions in weaving workshops, a checklist has been developed and an ergonomics index indicating the ergonomic conditions of the workshop has been proposed. To test and verify the checklist, 50 weaving workshops were visited and their ergonomic conditions were assessed. Based on the results some modifications were made and the checklist was shown to be an effective tool.
The study deals with working conditions in small private enterprises in Poland. Data come from 50 small enterprises from the Warsaw area. Information about the evaluation of working conditions and the existence of programmes for their improvement was gathered with the help of questionnaires addressed to employees and employers. The results constitute a "photograph" of the Polish reality at the beginning of its transition from planned to market economy. The study revealed a lack of programmes for the improvement of working conditions in a significant number of the enterprises studied as well as little interest in occupational safety on the part of employers (owners). The study also revealed that all decisions--including those about the improvement of working conditions--were made by employers. Hence, the need for the widest possible dissemination of knowledge on occupational safety and the protection of human in the working environment with particular stress put on employers. Employers who are knowledgeable in this field and who are aware of its importance can significantly influence the improvement of working conditions in small enterprises.
In industrially developing countries, a few ergonomists have directed great efforts towards developing ergonomics awareness among managers and workers in organizations. There is little research on the degree of their success, though. Furthermore, access of organizations to ergonomics knowledge is usually very difficult, especially in industrially developing countries. Thus, building ergonomics awareness is certainly the first phase of the process. Three companies from one industry (44 people: 14 females and 30 males) participated in a project aimed at improving their work system. At the beginning, we needed to create a common goal and ensure participation with appropriate ergonomics tools. The findings of this study were the key issue for the ergonomics intervention (i.e., a shared vision, awakened need of change and learning). Further, to build ergonomics awareness and develop a continuous learning process in the company, it was necessary to use more ergonomics tools through workers' participation in different workplaces