The use of a personal protective device (ppd) is a widely accepted method of safeguarding workers from occupational hazards in industrialized countries (IC) and an important method employed in developing countries (DC). Though protection is assured if the devices are worn constantly, it is unfortunate that due to discomfort and inconvenience, the majority of those exposed to hazards do not wear them. DCs which mainly import ppds from ICs are confronting many ergonomics problems, because the equipment designed for IC conditions is inappropriate for use in DCs, due to significant differences in user body sizes, environments and working methods. A questionnaire survey conducted among ppd manufacturers in 11 ICs revealed that 90% followed standards in manufacturing. Another survey conducted among health and safety authorities who responded on behalf of ppd users in 35 DCs revealed that the most common ergonomic causes of non-use are stresses from hotness, weight, improper fit and obstruction at work. While manufacturers place greater emphasis in the protection performance of the equipment, users in DCs refuse to wear it because the comfort needs are not fulfilled. Developing ergonomics standards for ppds seems to be a feasible way of persuading the manufacturers to provide ergonomic values in ppds. The need for maximum allowable comfort in the design, taking into consideration the user characteristics and protection factor is emphasized. To overcome the inherent discomforts that are extremely difficult to reduce without compromising the protection efficiency of a ppd, the principle of user adaptation seems to be a very important facet which has to be developed. A case study on safety helmets is reported. The use of a personal protective device (ppd) is a widely accepted method of safeguarding workers from occupational hazards in industrialized countries (IC) and an important method employed in developing countries (DC). Though protection is assured if the devices are worn constantly, it is unfortunate that due to discomfort and inconvenience, the majority of those exposed to hazards do not wear them. DCs which mainly import ppds from ICs are confronting many ergonomics problems, because the equipment designed for IC conditions is inappropriate for use in DCs, due to significant differences in user body sizes, environments and working methods. A questionnaire survey conducted among ppd manufacturers in 11 ICs revealed that 90% followed standards in manufacturing. Another survey conducted among health and safety authorities who responded on behalf of ppd users in 35 DCs revealed that the most common ergonomic causes of non-use are stresses from hotness, weight, improper fit and obstruction at work. While manufacturers place greater emphasis in the protection performance of the equipment, users in DCs refuse to wear it because the comfort needs are not fulfilled. Developing ergonomics standards for ppds seems to be a feasible way of persuading the manufacturers to provide ergonomic values in ppds. The need for maximum allowable comfort in the design, taking into consideration the user characteristics and protection factor is emphasized. To overcome the inherent discomforts that are extremely difficult to reduce without compromising the protection efficiency of a ppd, the principle of user adaptation seems to be a very important facet which has to be developed. A case study on safety helmets is reported.
The use of personal protective devices (ppd) is an important method to safeguard workers from occupational hazards both in industrialized and developing countries. Surveys have indicated that majority of those exposed to hazards are reluctant to use ppd because they are uncomfortable for such reasons as hotness, heaviness, ill fit, inconvenient, etc. Investigations have revealed that user-centered designs which satisfy the human factors needs of ppd, can reverse this trend and make ppd more acceptable. Because a questionnaire survey has shown that manufacturers are more inclined to adhere to standards, developing ergonomic standards seems to be a feasible method to persuade the manufacturers to provide the user needs in the design. Any unavoidable discomforts in ppd can be controlled by adaptation of users to ppd wearing.
In the use of personal protective devices (ppd) in the cold environment the wearability problems become more aggravated as the ppd must be worn over the cold protective clothing. Research in the area of human factors of ppd in cold environment has been scarce in the past. The lack of adequate user needs in currently used ppd in the cold environment, has resulted in discomfort, injury, non-use, and performance decrement among outdoor workers, particularly in the extreme cold regions, viz. Arctic countries. A preliminary study on the 'state of the art' was carried out on the use of ppd in cold environment which consisted of a literature survey, questionnaire survey among outdoor workers and information search through visits to relevant research institutions, discussions with researchers and participation in Conferences. The literature search carried out in 6 data bases revealed useful information about specific areas where wearability problems exist in ppd as well as some methods to be employed in research. The results of the questionnaire survey carried out in the Luleå region confirm that workers confront many inadequacies in the use of ppd in the cold climate. From the findings of this preliminary study three important kinds of ppd viz. safety gloves, safety shoes and safety helmets are discussed in this report. Human factors research for ppd in the cold environment with a view for improvement of wearability and use seem urgent.
An extraordinarily large share of research carried out in the near past on clothing comfort has been in the area of thermal comfort. Accordingly standards, norms and guidelines on thermal requirements of work-wear have been developed. Through behavioural adjustments people have learned to achieve thermal comfort even if the work clothes have slight deficiencies in thermal characteristics. It is beyond doubt that the thermal characteristics need careful consideration in the manufacture of work clothes. At the same time one must be aware that other human factors can also influence the overall wearability of clothing. This paper reviews the wearability and comfort of the clothing and work-wear to provide better understanding of the priorities in user needs in work clothes which can help plan future research and the need for new standards
The human factors or wearability needs of personal protective devices (ppd) and clothing (ppc) worn in the cold environment become more important as they must compromise with, and be adapted to, the clothing worn for cold protection. The occupational risks among outdoor workers in the cold can be aggravated if the wearability demands of ppd are not met. Failure to adequately meet user needs in currently used ppd in the cold environment has resulted in discomfort, injury, non-use and performance decrement among outdoor workers, particularly in the extreme cold regions. A preliminary study consisting of a literature survey in popular data bases and questionnaire survey among users of ppd, were carried out to ascertain what studies have already been conducted in this area and whether a wearability problem really exists among users, respectively. The literature revealed some specific areas where wearability problems exist and some research carried out on methods of testing of ergonomic characteristics of ppd. The questionnaire among ppd users in the cold climate confirmed that the workers do confront many inadequacies in the use of ppd. A case study carried out on ergonomic demands of safety shoes in the cold climate among users, manufacturers and experts revealed a similar trend of demands and priorities in ergonomics of shoes among all three groups. From the findings of the preliminary study it can be concluded that human factors research in ppd and particularly ppd worn on body extremities, viz. safety helmets, shoes and gloves, for use in the cold environment, seem urgent. Some research needs in the development of methods of testing for ppd evaluation are suggested.
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.
Testing for protection performance and human factors in personal protective devices (PPD) can be undertaken using a standardised methodology. The standardised methodology for performance testing is used for the certification of PPD. However, it is unfortunate that methods of testing for human factors and wearability of PPD are scarce, and even the methods that do exist are not always refined or standardised. In both hot and cold environments, thermal comfort is an important user need of PPD. To test the thermal characteristics of PPD, methods providing objective data are available, yet they are not always standardised. An exception exists for insulation testing of clothing, for which standardised methods have been developed. The fit of PPD is also a priority need among wearers. Clothing fit is often tested subjectively. The objective methods developed to test the fit of PPD and clothing again require refinement and standardisation. Wearability of PPD urgently requires the development and standardisation of both objective and subjective testing methods. This paper provides insights into some testing methods on human factors of PPD that have been particularly useful over the years.
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
Sri Lanka has declared 1996 as the 'Year of Productivity'. With a significant share of her national income being diverted for defence and security, productivity development becomes supreme for Sri Lanka's economic survival. Ergonomics or human factors which is a science well known for improving working conditions, is hardly known in Sri Lanka. Ergonomics applications enhance job satisfaction and productivity and maximise the product or systems quality by improving usability. A recent survey of three randomly selected large industrial work establishments in Sri Lanka revealed that much mismatch exists between workers and the machinery they are forced to work with, which hampers productivity and causes friction in the work places. A series of lectures conducted by an ergonomist among different professional groups and university students helped to create considerable awareness of the science of ergonomics. The participants were convinced that ergonomics can contribute immensely to productivity development in the country. Some strategies for ergonomics education in Sri Lanka which can also be adopted in other similar industrially developing countries are proposed.
Slips and falls on icy roads often result in fractures or sprains and is a major problem in Nordic countries. Walking trials by 25 subjects wearing four types of winter shoes on five different icy walking surfaces provided subjective and objective measures of tendency to slip and number of slips, respectively. Since friction is a major determinant of a slip, the influence of material spread on icy surfaces, the surface temperatures and the shoe soling characteristics versus the Coefficient of Friction (COF) of the shoes were measured. Sand and gravel on icy roads had positive effects on improving COF. The study revealed that the aetiology of slips and falls is multi-faceted and attempts to solve the problem must adopt a systems approach. Perception of risk, aging, training, experience and postural balance are other factors to be considered in preventing slips and falls. Future research should concentrate on the degree of impact of each factor to the aetiology of slips and falls, which can help to decide priority action in preventing slips and falls.
Unless the basic user needs are satisfied in safety helmets, it is difficult to get workers to wear them habitually and for long periods. Hotness, weight and fitting problems are major wearability issues that require improvements. The enormous need for an optimally designed helmet in China prompted a case study on comfort aspects in helmets. The subjective impressions of the wearers of test helmets provided useful information for design changes to improve comfort. The heat transfer measurements through helmets indicated the need for ventilation openings to be provided on the shell of plastic helmets. Due to the advantage of low weight and good ventilation, it is recommended that cane helmets be further developed to improve protection, wearability and durability, and subsequently be produced in large scale
Apparel exports bring in sizeable foreign income to Sri Lanka. To protect and promote this industry is a paramount need. This can be carried out by applying Human Factors/Ergonomics (HFE) which has proved to control negative effects at work places. This paper reports a case study which describes the demands and benefits of HFE in MAS Holdings which owns a large share of the apparel industry in Sri Lanka.The study consisted of walk through observation survey, a questionnaire survey and ergonomic work place analysis followed by a training programme to selected employees in three companies.Positive responses to questionnaires revealed good ergonomic practices in the work places surveyed. Ergonomically unfit chairs and potential hazards e.g. exposure to noise and hot environment were detected. It is seen that MAS have introduced strategies originated by Toyota Production System viz. 5S, Kaizen, six sigma etc., which are in fact ergonomic methods. A progressive project MAS boast of viz. ‘MAS Operating System’ (MOS) empowers training and development to employees.MAS Holdings has adequately realized the benefits of applying HFE as evident by the number of awards received. Relevant companies were advised to take appropriate corrective measures to control the potential hazards.
Past studies have shown large differences in body size between people of Industrialized Countries (ICs) and Industrially Developing Countries (IDCs). These differences can have negative effects on the usage of technology which IDCs today acquire to a great extent from ICs. At the same time, the number of students from IDCs seeking education and training in universities in ICs is increasing. This paper reports on the impact of human factors differences particularly body size differences between foreign and local students on the use of university facilities, based on anthropometric and questionnaire surveys carried out on a small scale by foreign graduate students of Lulea University, Sweden. The study revealed large differences in body sizes between local and foreign students. The questionnaire survey of foreign students showed that there are other significant human factors differences such as the use of a foreign language, viz. Swedish which is unique to Scandinavia, and the exposure to long cold winters. Whether these differences in human factors influence the acquisition of knowledge or learning capacity of foreign students is worth further investigation.
Safety shoes that are worn in a cold climate have to protect from work hazards and at the same time offer thermal comfort to the wearer. The lack of co-ordination between the two types of protection has made existing safety shoes clumsy and ill fitting. Work in the cold is more strenuous than working under normal conditions thus emphasising ergonomic or human factor aspects of safety shoes. In order to prioritize the needs of safety shoes used in the cold, questionnaire surveys were carried out among the users and manufacturers of safety shoes as well as among experts on personal protective devices. The surveys reveal that the following aspects are most important when designing safety shoes for a cold climate: fit, thermal comfort, protection from work hazards, low weight and anti-slip. To evaluate safety shoes with regard to the thermal properties a test method is being developed. The effects of air layer movements within the shoe and the foot has not previously been considered. In order to simulate real conditions, a new method for measuring the thermal properties of shoes will include foot movements taking into account heat losses due to the pumping effect. The method will be further developed to include simulated sweating.
In order to develop usable products, human needs and requirements have to be taken into consideration. By employing the QFD (Quality Function Deployment) method the human needs are systematically matched with the product characteristics, which can help to improve the product quality. In this paper the use of QFD in the area of ergonomics is discussed and a case study is presented, The QFD method was used in the case study to translate the needs of safety shoe users in the cold climate into product characteristics. The QFD analysis of the safety shoes revealed that the characteristics of the steel toecap were receiving the highest overall weighting, which means that improving the design of the steel toecap would lead to higher customer satisfaction. Relevance to industryThe importance of developing products that meet the customer or human needs is a priority area in the product development process. With knowledge in ergonomics it is possible to reveal information of the human needs and requirements. However, in the product development process it also is important to match the human needs with the product characteristics, which can be achieved by using the QFD method. The knowledge of ergonomics and the use of the QFD method are therefore useful tools in designing high quality products.
In the Chinese postal system, letters are sorted manually using a sorting frame, consisting of vertical and horizontal arrays of pigeon-holes of different dimensions. Letter sorting is a time consuming and a mentally intensive task involving repetitive movements of shoulder and hand muscles. Musculoskeletal complaints and disorders of the lower back, shoulder and hand occur frequently among the letter sorting workers. A total of 293 letter-sorters (71 males and 222 females) from Beijing Postal Sorting Office were subjected to a general health check-up including musculoskeletal disorders coupled with administration of a questionnaire. The worker's daily work load was evaluated by counting the number of letters sorted in each pigeon-hole in the sorting frame and also by considering their arm movements and body postures. The workplace dimensions were also measured. Results revealed that 62.1% of the workers complained of low back pain, 78.5% of shoulder pain and 48.8% of hand pain. A high percentage of workers seemed to have mental intensive symptoms, such as, headache, dizziness and drowsiness. Almost 25% of the female wokers indicated irregularity in their menstruation. An improved ergonomic design of the sorting frame is recommended.
Current research on slips and falls has mainly focused on floors and/or contaminated floors. Although icy and snowy surfaces near melting temperature are more slippery, more important still, slip and falls on icy and snowy surfaces involve not only outdoor workers, but also pedestrians and the general public; and occur in cold regions and in the winter season in many parts of the world. However, in comparison with the size of the problem, research work done so far in this area has been limited. The objective of this paper is to present a systems perspective of slip and fall accidents, with special focus on its occurrence on icy and snowy surfaces. In order to explore the aetiology of slip and fall accidents further, and to provide the basis for prevention, the authors put forward a systems model towards the slips and falls on icy and snowy surfaces based on a review of literature and current knowledge. Various contributing factors are systematically discussed to highlight the multi-factorial nature of the problem, providing the possibility of a multi-faceted approach to reach systematic prevention. Unresolved issues related to slips and falls on ice and snow are also identified, which necessitate further research.
The objectives of this study are to assess the perception of slipperiness, thermal comfort, and wearability of footwear used on icy surfaces, and the anti-slip effect of materials spread on ice using outdoor walking trials. Twenty-five subjects wore four types of footwear walking on five different icy surfaces. A five-point rating scale was used recording wearer's perception. The results showed that pure ice was perceived as very slippery. Spreading sand (180 g/m2) greatly decreased the slipperiness. Slip resistance, thermal insulation and wearability of footwear chosen were not properly integrated, and were ranked differently in four types of footwear. In addition to thermal insulation, prevention of slip and fall hazard by improving anti-slip property and wearability must also be priorities for development of footwear for use in a cold climate.
The objective of this paper was to investigate whether living experience in winter climate and winter sport helps to prevent slips and falls on ice and snow. A questionnaire survey was conducted among foreigners at Luleå University of Technology of Sweden, where winter season lasts for six months in a year. Seventy respondents replied. The results of ordinal regression showed that the slip frequency according to a 5-point rating scale decreased as the living experience in cold environments increased (B=-0.0113, p=0.019). A logistic regression was applied to model the probability of fall events occurrence based on the experience of living in cold climate. The results showed that the fall events reduced as living experience increased (B=-0.030, p=0.001). Chi-square test showed that fall events in those who took part in winter sport were significantly less than in those who did not participate in winter sport (χ2=10.745, p=0.001). The findings imply that experience of living in cold environments and training in gait balance on ice and snow can have positive effects in preventing slips and falls for inexperienced workers and pedestrians. This study also revealed that the majority of fall events happened on hard ice covered with snow while wearing ordinary winter footwear, indicating the need to improve slip resistance.