An investigation for determining the optimum length of chopsticks

Chopsticks are one of the most simple and popular hand tools ever invented by humans, but have not previously been investigated by ergonomists. Two laboratory studies were conducted in this research, using a randomised complete block design, to evaluate the effects of the length of the chopsticks on the food-serving performance of adults and children. Thirty-one male junior college students and 21 primary school pupils served as subjects for the experiment. The results showed that the food-pinching performance was significantly affected by the length of the chopsticks, and that chopsticks of about 240 and 180 mm long were optimal for adults and pupils, respectively. Based on these findings, the researchers suggested that families with children should provide both 240 and 180 mm long chopsticks. In addition, restaurants could provide 210 mm long chopsticks, considering the trade-offs between ergonomics and cost.     

An auxiliary device for chopsticks operation to improve the food-serving performance

Chopsticks are popular dining utensils in many Asian countries. It is well recognized that the pincers-pinching mode has been recommended for chopsticks operation for Chinese dining. The objective of this study was to propose an auxiliary device for transferring the subjects who had experienced scissors pinching to that of pincers pinching. A total of 30 male university students who used scissors pinching daily were recruited for the experiment. Subjects were requested to perform four simulated food-serving tasks under four different pinching stages. An additional testing was also performed for validation purpose. Results showed that the subjects had a better performance of food serving by the pincers-pinching method than by the scissors-pinching method, after familiarizing themselves with pincers pinching with the assistance of an auxiliary for 1 h. Because of the relatively shorter transferring time (1 h), the subjects still evaluated scissors pinching as their preferable ones. We suggested that this new auxiliary device could be used to teach or correct the chopsticks operation of people who are na?ve/children and are interested in chopsticks use or experienced in chopsticks scissors pinching.     

Effects of the handle diameter and tip angle of chopsticks on the food-serving performance of male subjects

The effects of chopsticks handle diameter and tip angle on the food-serving performance of pinching food, pulling food, shearing food and thrusting food, were investigated in this study. A total of 24 male subjects was tested using 12 pairs of experimental chopsticks, consisting of three types of different handle diameters and four types of different tip angles. These results indicated that chopstick handle diameter and tip angle have a significant influence on eating efficiency, and that these two variables have a significant interaction. In addition, chopstick tip diameter also had significant effects on performance at the four tasks and subjective ratings. Generally, according to the results, when the chopsticks design is presented in terms of handle diameter, tip angle and tip diameter, a pair of chopsticks with 6 mm handle diameter × 2 ° tip angle × 4 mm tip diameter would be optimum.     

The pincer chopsticks: the investigation of a new utensil in pinching function

The manipulation of chopsticks requires skillful motions of fingers. Therefore, it would be difficult to manipulate chopsticks for people with hand dysfunction. We designed a simple and convenient utensil, the pincer chopsticks, to simulate the pincers-pinching operation of traditional chopsticks. To compare the performance of the new device with that of traditional chopsticks and spoons, 32 volunteers applied these utensils to pick up four kinds of food with either hand. For dominant hands, the manipulation time of both pincer and traditional chopsticks was shorter than that of spoons, while using pincer chopsticks with non-dominant hands revealed the best performance among the three experimental utensils for users without experience. In this study, the newly designed pincer chopsticks demonstrated advantages for operation and performance. It has the potential to benefit patients with impaired hands.     

Ergonomics: influencing management behaviour

If successful, ergonomics can prevent accidents and improve occupational safety and health. This success creates 'non-events' that are counterintuitive to organizational goals of efficiency and optimization. It is, therefore, difficult to cost-justify ergonomics to organizations and their management. This paper presents three specific strategies and one general strategy for marketing ergonomics and occupational safety and health. The specific strategies involve: (1) understanding corporate culture and translating ergonomics into that cultural context; (2) identifying criteria that motivate people to use ergonomics; and (3) introducing ergonomics proactively as a tool for cost avoidance. The more general strategy suggests that we need to be more involved at the organizational design and management level. By operating at the organizational level we can make changes from within the management structure rather than making suggestions to management.     

Characterisation of forces exerted by the entire hand during the power grip: effect of the handle diameter

The objective of this study was to analyse the effect of the handle diameter on the grip forces exerted by the hand during a maximal power grip task. A handle ergometer, combining six instrumented beams and a pressure map, was used to determine the forces exerted by the palm side of the hand regrouping data from 10 anatomical sites (fingertips, phalanges, thumb, palm…). This methodology provided results giving new insight into the effect of the handle diameter on the forces exerted by the hand. First, it appeared that the relationship between the hand length/handle diameter ratio and the maximal grip force fit a U-inverted curve with maximal values observed for a handle diameter measuring 17.9% of the hand length. Second, it was showed that the handle diameter influenced the forces exerted on the anatomical sites of the hand. Finally, it was showed that the handle diameter influenced the finger force sharing particularly for the index and the little fingers. Practitioner Summary: This study analysed the effect of the handle diameter on the grip forces exerted by the hand during a maximal power grip force. This study showed that measurement of the totality of the forces exerted at the hand/handle interface is needed to better understand the ergonomics of handle tools. Our results could be re-used by designers and clinicians in order to develop handle tools which prevent hand pathologies.     

An approach to ergonomics evaluation of hand tools

Based on current knowledge of cumulative trauma disorders in the hand and forearm, related to the use of hand tools, an analysis was undertaken of variables to be considered in ergonomics evaluation of hand tools. Measurement methods were developed and an evaluation station was implemented. Measurement methods are physical, physiological or psychophysical. They focus on the tool, and on the effect of typical use of the tool on the operator. The evaluation station serves as a resource in the development, selection, and testing of tools for a given purpose.     

QFD: a methodological tool for integration of ergonomics at the design stage

As a marked increase in the number of musculoskeletal disorders was noted in many industrialized countries and more specifically in companies that require the use of hand tools, the French National Research and Safety Institute launched in 1999 a research program on the topic of integrating ergonomics into hand tool design. After a brief review of the problems of integrating ergonomics at the design stage, the paper shows how the "Quality Function Deployment" method has been applied to the design of a boning knife and it highlights the difficulties encountered. Then, it demonstrates how this method can be a methodological tool geared to greater ergonomics consideration in product design.     

Hand cumulative trauma disorders in Nigerian custom tailors: the need for redesign of manual scissors

Cutting scissors are important working tools for Nigerian custom tailors (CTs) but its usage apparently does not meet the ergonomics need of these artisans. A survey was carried out amongst CTs using questionnaires to obtain their background social-occupational demographics and observation methods to study their work performance, use of scissors and any cumulative trauma disorder (CTD) in their hands. Thicknesses of various fabrics were measured and comparison between Western world's custom tailoring job and the Nigerian type was done. The results showed some CTD risk factors with finger contusions on the 71 CTs evaluated. The right-hand contusions were traced to the constant usage of unpadded manual scissors with ungloved hands. Disparity between Western and Nigerian tailoring practice may account for the high occurrence of disorders in Nigerian CTs. Since hand dimensions are crucial in the design of hand tools, it is therefore concluded that hand anthropometry of Nigerian CTs and soft padding of manual scissors may mitigate CTD burdens on CTs' hands.     

Improving digital human modelling for proactive ergonomics in design

This paper presents the need to improve existing digital human models (DHMs) so they are better able to serve as effective ergonomics analysis and design tools. Existing DHMs are meant to be used by a designer early in a product development process when attempting to improve the physical design of vehicle interiors and manufacturing workplaces. The emphasis in this paper is placed on developing future DHMs that include valid posture and motion prediction models for various populations. It is argued that existing posture and motion prediction models now used in DHMs must be changed to become based on real motion data to assure validity for complex dynamic task simulations. It is further speculated that if valid human posture and motion prediction models are developed and used, these can be combined with psychophysical and biomechanical models to provide a much greater understanding of dynamic human performance and population specific limitations and that these new DHM models will ultimately provide a powerful ergonomics design tool.     

A hand-ergonomics training kit: development and evaluation of a package to support improved awareness and critical thinking

A need for a hand-ergonomics training kit has been identified to increase critical thinking concerning choice of hand tools. This study deals with the design, use and evaluation of a hand-ergonomics training kit for use in ergonomics training programmes. The effects on awareness of hand ergonomics among training course participants have been evaluated by means of a questionnaire and interviews at a car production plant in Sweden. The evaluation was carried out about one and a half years after training with the hand-ergonomics training kit. The training kit consists of a guide to practical exercises, equipment for measuring hand size and strength, examples of hand tools for use in practical exercises, equipment for testing and evaluating the hand tools and checklists and judgement forms for qualitative evaluation. In addition, the kit contains relevant scientifically based reference reports on hand ergonomics. The evaluation showed that the practical exercises with the hand-ergonomic training kit had, to a remarkable extent, increased individuals' awareness of anthropometric differences and of the importance of ergonomically well-designed hand tools. After the practical exercises with the training kit, communication within the plant when choosing hand tools seems to be based on objective criteria to a higher degree, however, the results indicate that this communication could be further improved.     

Improving digital human modelling for proactive ergonomics in design

This paper presents the need to improve existing digital human models (DHMs) so they are better able to serve as effective ergonomics analysis and design tools. Existing DHMs are meant to be used by a designer early in a product development process when attempting to improve the physical design of vehicle interiors and manufacturing workplaces. The emphasis in this paper is placed on developing future DHMs that include valid posture and motion prediction models for various populations. It is argued that existing posture and motion prediction models now used in DHMs must be changed to become based on real motion data to assure validity for complex dynamic task simulations. It is further speculated that if valid human posture and motion prediction models are developed and used, these can be combined with psychophysical and biomechanical models to provide a much greater understanding of dynamic human performance and population specific limitations and that these new DHM models will ultimately provide a powerful ergonomics design tool.     

Optimisation of a laparoscopic tool handle dimension based on ergonomic analysis

The techniques of Minimally Invasive Surgery (MIS) have quickly entered everyday surgical practice, and are steadily displacing traditional procedures. The reason is the advantages they have for the patient, both during surgery and in postoperative recovery. However, poor ergonomic design of the instruments used in MIS causes surgeons muscle fatigue and injuries (such as paraesthesia, etc.), forcing them to refrain from performing operations for several days or even weeks, which supposes costly losses of time and money.The objective of the present study was to optimize the handle size of a laparoscopic grasper tool. The study was conducted with the participation of 135 surgeons. Each participant performed a series of trials in which they executed the same action several times with the same tool (same in terms of the geometrical form of the handle) but of different dimensions (size) in order to determine the optimal diameter. The results were then subjected to a statistical analysis to study the relationship between the size of the surgeon's hand and the perceived optimal diameter of the handle from an ergonomic point of view.There stands out among the conclusions drawn from the study that there is indeed a relationship between the size of a surgeon's hand and the optimal handle size for them to use in surgery. In this sense, one of the most relevant results is that it is necessary to consider four different handle sizes groups (XS, S, M and L) instead of the three groups proposed by Greiner (1991). Another interesting result is that all surgeons in the smallest handle size group (XS) were women, and in the L group were men. Also it was interesting to note that, for the intermediate hand sizes (S and M), the sex of the surgeon conditioned the optimal handle size, and that the surgeon's experience and surgeon's handedness were not factors affecting the optimal diameter of the handle.Relevance to industryThe results of this work can assist designers of grasping tools in developing better handles and provide required sizing for improved comfort, performance and lowering the risk of cumulative traumatic disorders. It is important to note that it is not necessary to design the handle of the grasper tool for each surgeon hand, but also with four hand size categories is possible to offer an appropriate handle size for all surgeons independently of their hand sizes.     

The Ergonomics Society--the Society Lectures 1999: the next 50 years: future challenges and opportunities for empathy in our science

To stay relevant and applicable in a rapidly changing world, ergonomics must meet several challenges. The paper explores these challenges and how the profession might respond. It is proposed that there are opportunities, and a need, to embrace empathy as a legitimate and useful tool. Empathy has value in three main areas. In research we can broaden our understanding of people and situations, learning 'why' as well as 'how and what' people do. Second, by identifying with the emotional as well as intellectual concerns of sponsors and colleagues from other professions, we inspire trust and confidence, adding value to our collective efforts in collaborative work. Third, through methods such as role-playing and story telling, empathy is a powerful tool for getting ergonomics issues across to implementers and influencing outcomes. Care is needed to balance empathy with systematic observation in the tradition of the scientific method; the power of empathy is in combining it with objective methods to make full use of our abilities as human scientists.     

The next 50 years: future challenges and opportunities for empathy in our science

To stay relevant and applicable in a rapidly changing world, ergonomics must meet several challenges. The paper explores these challenges and how the profession might respond. It is proposed that there are opportunities, and a need, to embrace empathy as a legitimate and useful tool. Empathy has value in three main areas. In research we can broaden our understanding of people and situations, learning ‘why’ as well as ‘how and what’ people do. Second, by identifying with the emotional as well as intellectual concerns of sponsors and colleagues from other professions, we inspire trust and confidence, adding value to our collective efforts in collaborative work. Third, through methods such as role-playing and story telling, empathy is a powerful tool for getting ergonomics issues across to implementers and influencing outcomes. Care is needed to balance empathy with systematic observation in the tradition of the scientific method; the power of empathy is in combining it with objective methods to make full use of our abilities as human scientists.     

Contributions from cognitive engineering to requirements specifications for complex sociotechnical systems: A case study in the context of healthcare in Brazil

This paper aims at presenting a case study on the use of human factors and ergonomics to enhance requirement specifications for complex sociotechnical system support tools through enhancing the understanding of human performance within the business domain and the indication of high‐value requirements candidates to information technology support. This work uses methods based on cognitive engineering to build representations of the business domain, highlighting workers’ needs, and contributing to the improvement of software requirements specifications, used in the healthcare domain. As the human factors discipline fits between human sciences and technology design, we believe that its concepts can be combined with software engineering to improve understanding of how people work, enabling the design of better information technology.     

The effect of hand tools’ handle shape on upper extremity comfort and postural discomfort among hand-woven shoemaking workers

Hand tools are widely used in a large number of occupations. Many workers have to use hand tools to accomplish their duties. This may cause work-related Upper Extremities Musculoskeletal Disorders (UEMSDs). The present study was conducted in Iranian hand-woven shoe industry to (a) investigate the design of hand tools currently used in hand-woven shoemaking operation and (b) design/redesign the tools' handles based on anthropometric tables and ergonomic principles. Based on Iranian workers' anthropometric tables, new handles with different shapes were designed and made for hand tools currently used in hand-woven shoemaking operation (e.g., awl and cloth cutting tool). Hand postures and postural comfort and discomfort were investigated via rating technique using Comfort Questionnaire for Hand Tools (CQH) and upper extremities body map. The results of CQH showed that the handle shape had a significant influence on the hand posture and perceived postural discomfort in the upper extremities. The new ergonomically designed handles were perceived to be more comfortable compared to the traditional ones. Additionally, the new handles improved the hand posture during the operation and reduced the severity of discomfort in the upper extremities compared to the tools with conventional handles. The findings of this study revealed that designing the hand tools’ handles based on ergonomic principles and using anthropometric tables could improve the hand posture, increase comfort, and decrease discomfort in the upper extremities. By this means, reduction in work-related UEMSDs is expected.     

Application of the QFD as a design approach to ensure comfort in using hand tools: Can the design team complete the House of Quality appropriately?

Quality Function Deployment is proposed as an effective design method to integrate ergonomics needs and comfort into hand tool design because it explicitly addresses the translation of customer needs into engineering characteristics. A crucial step during QFD concerns the linking of engineering characteristics to customer needs in the House of Quality by the design team. It is generally assumed (looking at all the QFD success stories) that design teams can accurately predict the correlations between customer needs and engineering characteristics (also referred to as “Whats”/“Hows” correlations). This paper explicitly tests this assumption by comparing the “Whats”/“Hows” correlations estimated by a design team with those observed in a systematic user evaluation study, which has not been done before. Testing the assumption is important, because inaccurate estimates may lead to ergonomically ineffective (re)design of hand tools and a waste of company resources. Results revealed that the design team's correlation estimates were not as accurate as is generally assumed. Twenty-five percent of the estimates differed significantly with those observed in the user evaluation study. Thus, QFD is a useful method to assist design teams in designing ergonomically more comfortable hand tools, but only on the condition that the correlations between customer needs and engineering characteristics are validated, preferably by means of a systematic user evaluation study.     

Green ergonomics: definition and scope

This paper demonstrates that the goals of ergonomics (i.e. effectiveness, efficiency, health, safety and usability) are closely aligned with the goals of design for environmental sustainability. In this paper, the term ‘green ergonomics’ is conceptualised to specifically describe ergonomics interventions with a pro-nature emphasis. Green ergonomics is focused on the bi-directional connections between human systems and nature. This involves looking at (1) how ergonomics design and evaluation might be used to conserve, preserve, and restore nature and (2) how ecosystem services might be harnessed to facilitate the improved wellbeing and effectiveness of human systems. The paper proposes the scope of green ergonomics based on these bi-directional relationships in the areas of the design of low resource systems and products, the design of green jobs, and the design for behaviour change. Suggestions for further work in the green ergonomics domain are also made.

Practitioner Summary: Given the enormous environmental challenges facing modern industrial society, this paper encourages ergonomics science to embrace a pro-nature understanding of work design and research. This paper sets out the role for green ergonomics based on an appreciation of the human–nature connections that have been integrated with our understanding of ergonomics science and practice.     

An integral system‐ergonomic approach for IT‐based process management in complex work environments by example of manufacturing and health care

Recent trends in manufacturing and health care move these two work systems closer together from a system ergonomics point of view. Individual treatment of products, especially patients, by specialists in a distributed environment demand information technology (IT)‐based support suitable for complex systems. IT‐based support of processes in complex systems is difficult due to the lack of standard processes. IT support also means to rethink processes to use efficiency potentials. Close cooperation of users and software developers is needed to increase the ergonomic quality of the system. Therefore, suitable tools are needed: UML is available as the standard industry modeling language, Zope/Plone as the quasi‐standard for content management systems, SimPy as an object‐oriented simulation tool for event‐triggered processes, and ACT‐R as a powerful cognitive architecture for simulation of human information processes. The integration of these tools enables system‐ergonomic support of processes in the complex work system as well as of the development and deployment process. It is the base of an integral system‐ergonomic approach for IT‐based process management. Knowledge gained during process analysis either enters models or leads to the extension and adaptation of the tool chain. The models serve as basis for discussion among system ergonomists, programmers, and specialists from the work system. Further, they are understood by simulation and process support tools. Transcoding efforts between humans with different professional backgrounds and machines are reduced, and the flexibility demanded by complex systems is met. © 2008 Wiley Periodicals, Inc.