Handle displacement and operator responses to pneumatic nutrunner torque buildup

The objective of this study is to investigate the workstation and tool effects on the responses of the powered hand tool operator reacting against the impulsive reaction forces that may be associated with upper extremity musculoskeletal disorders. The study demonstrated a means of direct measurement of force at the interface between the tool and the operator. Fifteen experienced male operators performed three independent work configurations: pistol grip and right angle tools used on the horizontal surface and pistol grip tools used on the vertical surface, in the laboratory. A full factorial experiment consisting of 36 conditions was designed to examine the effects of working height, distance, tool, and fastener joint hardness on handle displacement and grip forces. The results indicate that operator responses were affected by different factors depending on the work configuration. When pistol grip tools were used on the vertical surface, the mean handle displacement decreased from 9.9 degrees to 7.3 degrees as the working height increased from 30 cm below shoulder to 30 cm above shoulder. When right angle tools were used, the greatest handle displacement (51.1mm) and grip force (84.7% MVC) during torque reactions were measured at 30 cm below elbow and 40% forward reach away from the operator. This study provides quantitative information that can be used for workstation design and tool selection to reduce the torque reaction experienced by powered nutrunner operators.     

From industrial safety to corporate health management

Occupational health and safety is one of the most important topics of ergonomics. In many countries the practical issues are addressed in worker protection laws or rules and most companies have some sort of occupational health and safety system. As with many other ergonomics approaches, such activities are often necessary because of legal requirements. Such efforts are often viewed by management as primarily cost intensive. To change this image, it would be helpful to have a more positive, management-oriented approach. Corporate health management as a module of an integrated management system can fulfil this goal.     

Understanding workplace violence: The value of a systems perspective

Workplace violence is a leading form of occupational injury and fatality, but has received little attention from the ergonomics research community. The paper reports findings from the 2012 New Zealand Workplace Violence Survey, and examines the workplace violence experience of 86 New Zealand organisations and the perceptions of occupational health and safety professionals from a systems perspective. Over 50% of respondents reported violence cases in their organisation, with perpetrators evenly split between co-workers and external sources such as patients. Highest reported levels of violence were observed for agriculture, forestry and construction sectors. Highest risk factor ratings were reported for interpersonal and organisational factors, notably interpersonal communication, time pressure and workloads, with lowest ratings for environmental factors. A range of violence prevention measures were reported, although most organisations relied on single control measures, suggesting unmanaged violence risks were common among the sample.     

Worker productivity, and occupational health and safety issues in selected industries

The main objective of this research was to identify factors that affected worker productivity, occupational health and safety in selected industries in a developing country. Fifty production managers participated in the study. Fifty-four percent of the managers reported hot environmental conditions, 28% a noisy environment, and 26% a lack of resources and facilities. Managers received worker complaints of fatigue, back pain, upper-body pain, hand and wrist pain and headaches. Management (88%) acknowledged not having knowledge or access to ergonomics information. Ninety-four percent of the companies did not carry out ergonomic assessments. A significant correlation (p<0.01) was found among productivity indicators and health and organizational attributes. Lack of skills in ergonomics and training, communication and resources are believed to be some of the factors contributing to the poor ergonomic conditions and consequent loss of worker productivity and reduced health and safety in these industries.     

Cost effectiveness of ergonomic redesign of electronic motherboard

A case study to illustrate the cost effectiveness of ergonomic redesign of electronic motherboard was presented. The factory was running at a loss due to the high costs of rejects and poor quality and productivity. Subjective assessments and direct observations were made on the factory. Investigation revealed that due to motherboard design errors, the machine had difficulty in placing integrated circuits onto the pads, the operators had much difficulty in manual soldering certain components and much unproductive manual cleaning (MC) was required. Consequently, there were high rejects and occupational health and safety (OHS) problems, such as, boredom and work discomfort. Also, much labour and machine costs were spent on repairs. The motherboard was redesigned to correct the design errors, to allow more components to be machine soldered and to reduce MC. This eliminated rejects, reduced repairs, saved US dollars 581495/year and improved operators' OHS. The customer also saved US dollars 142105/year on loss of business.     

遗传算法在Sierpinski地毯Hausdorff测度计算中的研究与应用

遗传算法是一种高效的全局优化概率搜索算法,基于分形几何中测度难以计算的问题,本文提出了采用遗传算法来求解Sierpinski地毯近似最优Hausdorff测度的思想,并研究和分析了遗传算法在Sierpinski地毯Hausdorff测度计算中的具体实现。     

The impact and feasibility of international/national standards in the prevention of musculoskeletal injuries in developing countries

This paper considers various facets of a preventive scheme for musculoskeletal injuries and examines the role of standards in the terminology, investigation, reporting, compilation and computation in such schemes.     

Implementation programme of the Swedish ordinance concerning work postures and working movements

Ergonomically-rclated occupational injuries have been increasingly recognized in Sweden. The official injury statistics show that ergonomically-related injuries accounted for about 20% of all reported occupational injuries (ISA 1985). On 1 January 1984 an ordinance concerning work postures and working movements was passed. It was built upon and is a complement to the Work Environment Act of 1978. There are in Sweden about 400 labour inspectors in 19 regional Labour Inspectorates, to ensure among other things that rules concerning the occupational environment are complied with at the workplace level. Sweden has a working population of about 4 million people. To implement the above-mentioned ordinance, a 2-year implementation programme was set up. The labour inspectors first identified major areas with severe non-ergonomic working conditions, in all areas of work. Six typical work situations were then selected and the inspectors were asked to pay special attention to them, and to intensify their efforts on these work situations, during a 10-month period. Eighteen months after the ordinance came into effect, the implementation programme and the labour inspectorate input was evaluated. The preliminary results showed an overall increase in ergonomic awareness. The ordinance was distributed in about 120000 copies, and the labour inspectors found it to be a useful tool in their work. Citations concerning ergonomics had increased considerably during this period.     

Effects of user experience,working posture and joint hardness on powered nutrunner torque reactions

Powered hand tools produce reaction forces that may be associated with upper extremity musculoskeletal disorders. The handle displacement, grip force and upper limb muscle activity (electromyography (EMG)) due to the effects of operator experience, working height and distance, type of tool and fastener joint hardness were measured in this study with 15 experienced and 15 novice nutrunner users. The results show that when pistol grip handles were used to work on a horizontal surface, experienced users allowed an average handle displacement of 7.9°, while novice users allowed 11.5°. Average EMG scaled by reference voluntary contraction (RVC) at forearm flexors, forearm extensors and biceps were greater for experienced users (318% RVC, 285% RVC, 143% RVC, respectively) than for novice users (246% RVC, 219% RVC, 113% RVC, respectively). Experienced users exerted more grip force than novice users when using right angle handles, but less force when using pistol grip handles. The results suggest that it is possible to minimize tool handle displacement by adapting the workplace layout to permit different working postures for each user group.     

Risk perception of construction equipment operators on construction sites of Turkey

Turkey has been an attractive country for construction industry in the last decade. Many large-scale construction projects, which have been realized by both international and local construction firms, helped the economy and provided employment opportunities for many. At the same time, many construction workers have been losing their lives on construction sites, which involve the usage of heavy equipment on a daily basis.Past research studies suggest that employee participation and their perception of safety risks could be valuable for determining and eliminating hazards on construction site. Therefore, this study aimed to determine and evaluate the risk perception of construction equipment operators in Turkey. The study is mainly based on a questionnaire survey performed in 51 construction projects that involved 198 heavy equipment operators. A statistical analysis was first performed on the results of the survey to observe the frequency distribution of parameters, such as safety and health training, using flagger, experience, type of equipment, working conditions and other project related data. Then, statistical methods such as, t-test, ANOVA analysis, Kruskall–Wallis one way analysis of variance, and Mann–Whitney U test were performed to seek statistically meaningful differences in risk perception of operator groups with different attributes.Results revealed the importance of safety and health training as well as working with an assistant, such as a flagger. It was observed that operators who took safety and health training and operators who worked with flaggers perceived risk differently than others. It was also found that the project type influences the risk perception of equipment operators due to diversity of construction equipment activities performed, as well as number of incidents occurred in those projects.Relevance to industryThe authors expect this research to lead to discussion and further research on risk assessment for construction industry. The risk assessment findings of this study, in particular, could help the safety professionals detect possible unforeseen risks and design safety and health plans for construction sites that require usage of heavy equipment on a daily basis. Heavy equipment manufacturers could also devise a similar research that involves operators’ risk perception to design more ergonomic and safe equipment.     

地域特色在新疆织毯装饰上的表现

织毯为人们的日常生活增添了一抹绚丽、浪漫的色彩。新疆拥有广阔的天然草地面积,畜牧业发达,因而产生了大量的优质毛料,为织毯的发展奠定了基础。同时众多少数民族、游牧民族聚居于此,不同的民俗、不同的宗教影响于织毯的装饰风格,使新疆地毯极具地域特点。随着社会的发展,织毯的社会功能逐渐高于它的使用功能。织毯除了满足人们生理需求与视觉享受之余,更多的是对其地域思想、地域文化的体现,并对其进行推广与传播。     

Stand up: comparison of two electrical screed levelling machines to reduce the work demands for the knees and low back among floor layers

Electrical screed levelling machines are developed to reduce kneeling and trunk flexion of sand–cement-bound screed floor layers. An observational intervention study among 10 floor layers was performed to assess the differences between a self-propelled and a manually moved machine. The outcome measures were work demands, production time, perceived load, discomfort and applicability. Compared to the self-propelled machine, the duration of kneeling (?13 min; p = 0.003) and trunk flexion (?12 min; p < 0.001) was shorter using the manually moved machine, and the duration of pushing and pulling increased (?39 min; p < 0.001). No significant or relevant differences were found for production time, perceived load and discomfort. Nine out of ten floor layers found the manually moved machine applicable and three out of ten found the self-propelled machine applicable. When compared with the traditional manner of floor laying, both electrical machines reduced the exposure towards kneeling and trunk flexion.

Practitioner Summary: Electrical machines may help to reduce high physical work demands on floor layers. A manually moved machine is better applicable for the installation of screed floors in residences with smaller floor areas. A self-propelled machine is better applicable on large floor areas with a minimum width of 4 m.     

Compensation for occupational injuries and diseases: its effect upon prevention at the workplace

Abstract

In Switzerland, as in many other industrialized countries, the nature and extent of prevention at the workplace is determined, at least partially, by known cases of compensated occupational injuries and diseases. At both the national and international levels ∥ILO conventions) injuries and diseases that fit appropriate lists and definitions are eligible for compensation. It has been found, based upon an investigation of a representative sample (965 subjects) of the working population in the French-speaking region of Switzerland, that this restrictive view does not take into account the fact that a large proportion of injuries and diseases are claimed by the victims to be caused by their job. These injuries and diseases, responsible for at least one month's absence from work, are not considered to be eligible for compensation but must be covered by the patient's own insurance. Moreover, the survey showed that workers considered the ill effects on health and safety to be a consequence less of the physical working environment than of the work organization, and that this category of risks was not recognized. Thus, in addition to the reduction of hazards by the application of industrial hygiene, an informed improvement of the workplace and the work organization was required. Consequently, laws and regulations on occupational injuries and diseases should be changed in order to emphasize the role of more appropriate preventive tools, which includes ergonomics.