The Influence of Different Hand Tool Designs on the Perception of Aesthetics, Ergonomics and Usability

The perception of products in terms of ergonomics, usability and beauty remains to be important issues in product design. A positive impression must be made for consumers. A product must be ergonomic and visually appealing in order for the product to be used safely and effectively. Therefore, understanding the perception of ergonomics, usability and aesthetics is an important issue for product designers. Apart from being visually appealing, the product must be perceived as ergonomic and usable, as the ergonomic design of hand tools may alleviate the occurence of upper limb musculoskeletal disorders. In this study, the perception of ergonomics, usability and aesthetics were evaluated for an existing hand tool (R1) and a proposed design (R2). Questions related to ergonomics, usability and aesthetics were combined to form a survey. A sample of 50 undergraduates were chosen as the respondents. The results indicated that R1 was rated less visually appealing than the new design, R2. Participants perceived the new design, R2 to be more ergonomic and usable than R1. Furthermore, a weak correlation between perception of ergonomics, usability and aesthetics were observed for this study. In general, ergonomic design factors are hard to be perceived by consumers. Possible ramifications of this relationship are discussed in this paper

An evaluation of arborist handsaws

A review of the scientific literature reveals little research on the ergonomics of handsaws and no literature on the specific challenges of arborist saws (saws for cutting and pruning living trees). This study was designed to provide some insight into the effects of saw design and height of sawing activity on the biomechanical response of the upper extremity. Eighteen participants performed a simple sawing task at three different heights using six different arborist handsaws. As they performed this task, the electromyographic activity of several muscle groups of the forearm (flexor and extensor digitorum), arm (biceps brachii long and short heads) and shoulder girdle (posterior deltoid, infraspinatus and latissimus dorsi) were sampled. Also gathered were the wrist postures in the radial/ulnar plane at the beginning and ending of the sawing stroke, the time to complete the sawing task and a subjective ranking of the six different saws. The results show an interesting mix of biomechanical and subjective responses that provide insight into handsaw design. First, there were tradeoffs among muscle groups as a function of work height. As work height increased the biceps muscles increased their activation levels (∼19%) while the posterior deltoid activity decreased (∼17%) with the higher location. The results also showed the benefits of a bent handle design (average 21% reduction in ulnar deviation). The subjective responses of the participants generally supported the productivity data, with the saws demonstrating the shortest task completion time also being the ones most highly ranked

Investigation of Factors Influencing Ergonomic Characteristics of Water Bottle Handles

Increasingly competitive market environment pushes products and their packaging to meet functional and aesthetic requirements and expectations of consumers. Ergonomic features are one of the most important features for fulfilling consumer expectations and achieving a satisfying user experience. Drinking water in retail is commonly packaged in PET bottles ranging from 0.2 up to 6 litres. The weight of the 6-litre bottle is roughly 6 kilos which can produce strain on the hand while carried from the place of purchase to the place of usage. The goal of this research was to investigate the influence of water bottle handles and to determine how much does handle length, width, and curvature of the grip\u27s edges affect the comfort of product use. This research presents objective experimental measurements and subjective judgment regarding ergonomic characteristics of the 5-6 litre water bottle handles, based on the variations in their shape and dimensions

The Influence of Hand Tool Design on Hand Grip Strength: A Review

Hand is made up of bones, tendons, ligaments, nerves and blood vessels that can be easily debilitated and injured if the hand tool is not design ergonomically. Recently researchers have examined the effects of individual, environmental and occupational factors on hand grip strength. However, information on the influence of hand tool design on hand grip strength is still lacking. The aim of this paper is to provide a comprehensive review of factors influencing hand grip strength focusing more towards hand tool design factors. The authors searched the journal articles, book and guidelines from the online databases of Google Scholar, ScienceDirect and Pubmed. Fourteen factors of hand tools design were found to have significant effect on the hand grip strength.  The handle size shows the most significant factor for hand grip strength

Comprehensive hand and power tool evaluation for comprehensive knowledge & expected returns (C.H.E.C.K.E.R.): a novel method for maximizing returns in industrial tool selection

This dissertation begins with an investigation into how hand tool purchasing decisions are made in the enterprise environment and how hand tool purchasing and evaluation are conducted from an academic perspective. A hand tool, as a type of equipment used by people to create products and complete projects, provides direct physical feedback to the user. Given its daily use, poor tool choices can result in significant financial losses due to decreased productivity, higher defect rates, and increased injuries, it is surprising to observe that traditional hand tool purchasing processes are rarely comprehensive, often overlooking important factors such as ergonomic impact, efficiency, and output quality. This dissertation further investigates a proposed four-pronged hand tool evaluation system, which was tested in comparison with the traditional hand tool evaluation. Results showed that the traditional hand tool evaluation would not provide a comprehensive result and could result in a significant financial impact for buyers when deployed. Additionally, a basic point system, Competitive Advantage Point (CAP) system, has been created to help visualize the potential financial impact of hand tool selection and the differences between the proposed comprehensive hand tool evaluation and the traditional approach. This dissertation investigates the impact of hand tools on workplace efficiency, emphasizing the importance of proper selection through engineering and ergonomics evaluations. Existing literature review shows the majority of them focus on design, hazard outputs, and user feedback in hand tool evaluation systems and ergonomics studies. The findings underscore the necessity for a future-oriented, financially-focused, and comprehensive hand tool evaluation system to address current limitations. This dissertation investigates the critical role of hand tools in the workplace, emphasizing the potential impact on work efficiency and safety through improper selection. A comprehensive literature review focused on human factors studies at key stages of hand tools' life cycles, revealing a majority of the buyer emphasis on price and perceived quality over ergonomic features, and proposes a hand tool heuristic evaluation method, integrating both human factors and financial considerations. This dissertation next coins the term Human-Hand Tool Interaction (HHTI) and creates a first-of-its-kind, user-friendly, comprehensive hand tool evaluation system - Comprehensive Hand Tool Evaluation for Comprehensive Knowledge & Expected Returns (C.H.E.C.K.E.R.) based on previous research. The major contribution of the C.H.E.C.K.E.R. method is its ease of use, comprehensiveness considering direct and indirect costs, human factors design, industrial hygiene, integrated with expected value, and Design Failure Mode and Effect Analysis (DFMEA) principles. Sixteen experts in enterprise hand tool purchasing from various industries, averaging 13.25 years of procurement experience, participated in the study. After being introduced to the C.H.E.C.K.E.R. method, a significant improvement in tool selection was observed. In one scenario, the selection of financially suboptimal tools dropped from 46.75% to 6.25% after the experts reviewed the C.H.E.C.K.E.R. results for each hand tool candidate. Most participants responded positively, with 13 out of 16 finding the method easy to use and expressing interest in adopting it for future purchasing decisions. The study highlighted C.H.E.C.K.E.R.'s effectiveness in meeting industry demands for a user-friendly selection method that thoroughly evaluates tools in their operational context, incorporates human factors in design, addresses industrial hygiene, and provides financial justification. Additionally, the method's flexibility for both in-person and online use makes it an accessible and valuable resource for optimizing hand tool procurement decisions

Análise do conforto na atividade de desossa de carne bovina: um estudo de caso

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.Esta pesquisa teve como objetivo investigar o conforto na atividade de desossa de carne bovina. A pesquisa foi dividida em duas etapas: teórica e empírica. Na primeira, foi realizado um levantamento bibliográfico sobre os aspectos conceituais do conforto, elaborado um modelo conceitual e dimensões de análise do fenômeno. Na segunda etapa foi realizado um estudo de caso, num frigorífico de carne bovina, baseado nas dimensões de análise do conforto: ambiental, mental e física. Para análise da dimensão mental, foram realizadas observações da atividade e utilizado recursos como: filmagens, fotografias, registro de verbalizações e anotações livres. Foram aplicados ainda: questionário de perfil dos sujeitos, usabilidade, desconforto/dor, questionário de atributos de conforto, produtividade e qualidade de desossa. Para análise da dimensão física foi realizada a contagem dos tempos e movimentos, através de filmagens dos ciclos de desossa e antropometria das mãos dos sujeitos, através do método da biofotogrametria. Para averiguação da dimensão ambiental do posto de desossa, foi feita análise do layout, iluminação, temperatura e ruído. Os resultados foram analisados através de estatística descritiva e os dados foram tratados a partir da análise de gráficos, figuras e tabelas, com recursos de média e porcentagens. Os resultados da pesquisa quanto aos aspectos teóricos apontaram que o conceito de conforto se constitui pela via dos conceitos de complexidade, subjetividade, percepção, interação e crenças e pode ser estudado sob três dimensões principais (física, mental e ambiental) que são avaliados à luz das atividades executadas pelos sujeitos no seu sistema de trabalho. Quanto ao estudo de caso, os resultados apontaram que 50% dos sujeitos percebem conforto no uso da faca de desossa atualmente utilizada e os principais atributos geradores de conforto, em ordem decrescente, foram: afiação e tipo de lâmina. Quanto ao índice de desconforto/dor, os dados mais significativos foram: dedos (58%) e ombro (42%); no entanto 75% dos sujeitos referiram ter tido dor e/ou formigamento no último ano. Os fatores relacionados ao ambiente podem contribuir a baixa taxa de conforto percebida, já que apresentam dados que indicam necessidade de medidas corretivas como: ruídos de impacto, baixa luminância, vestimenta não condizente com a baixa temperatura da sala de desossa e resíduos no chão que podem contribuir aos riscos de acidentes. Quanto aos aspectos físicos, a atividade foi considerada repetitiva, com desvio radial do punho freqüente, principalmente no ciclo de desossa do peito (dianteiro do gado). A análise antropométrica evidenciou variação de dados com relação a outros estudos, bem como, variados manejos com a faca. Então, com este estudo pode-se concluir que a atividade de desossa apresenta indicadores de desconforto/dor que podem estar afetando a percepção de conforto dos sujeitos, durante o exercício de suas atividades. A faca atualmente utilizada necessita melhorias no que se refere à qualidade do cabo e lâmina, de forma a contribuir para o conforto dos trabalhadores na atividade de desossa. Possivelmente uma faca projetada com base neste estudo poderá promover maior conforto, satisfação, produtividade e prevenir o desconforto/dor, que pode ser um agravante a incidência de DORTs (Doenças Osteomusculares Relacionadas ao Trabalho). This work aimed to investigate the comfort on the activity of boning removal of cattle meat. For reaching this goal, this survey was divided in two stages: theoretical and experimental. On the first, it was done a bibliographical survey about the conceptual aspects of comfort, performed a conceptual model and analysis dimensions of the phenomenon. On the second stage, it was done a case study, in a meat storage room of cattle meat, based on the comfort analysis dimensions: environmental, mental and physical. For the mental dimension analysis, it was performed the observation of the job and it was used some resources, such as: filming, taking pictures, registering verbalizations and free notes. It was still applied: a questionnaire of the participants profile, usability, discomfort a questionnaire of comfort attributes, discomfort, productivity and bone removal quality. For the physical dimension analysis it was counted the timing and movements, through the filming of the bone removal cycles and anthropometry of the participant's hands, through the biophotogrametry method. For the inquiry of the environmental dimension, it was performed the analysis of the furniture layout, lightening, temperature and noise. The results were verified through the descriptive statistics and the data were observed with the graphical analysis, pictures and charts, with the average and percentage resources. The theoretical results of the research pointed that the comfort concept is formed by the complexity concepts, subjectivity, perception, perception, interaction and beliefs. It can be seen through three main dimensions (physical, mental and environmental) which are evaluated under the vision of the activities performed by the participants on his job routine. Related to the case study, the results pointed that 50% of the participants realize the comfort on the use of the boning knife, currently used and the main factors, responsible for the comfort, in a decreasing order were: sharpening and the blade type. The results pointed on the case study noticed that 50% of the participants can notice comfort on the use of the boning knife, currently used and the main factors, responsible for the comfort, in a decreasing order were: sharpening and the blade type. As to the discomfort index, the main data realized were: fingers (58%) and shoulder (42%); however, 75% of the participants complained of feeling pain or itching last year. The factors related to the environment can contribute to the low rate of comfort perception, since they present some evidences, which can interfere on the phenomenon perception, mainly the noise, due to the presence of impact noises, low lightening, clothes not suitable to the low temperature of the bone removal room and low air speed, which added to the low temperature, and some leftovers which can contribute to the risks of accident, causing a thermal discomfort on the participants. As to the physical aspects, this activity was considered repetitive, with wrist deviation related to the frequent neutral position, especially on the cycle of bone removal of the cattle chest fore part. The anthropometrical analysis has noticed a high variation of the data, to other studies, as well as, some changes on the knife use, considering that it doesn't reach all the anthropometrical needs of all the participants. The anthropometrical analysis showed clearly a variation of the data compared to other studies, as well as, different ways of dealing with the knife. Finally, with this study, we can conclude that the boning removal activity presents some index of discomfort which can affect the perception of the worker´s comfort during their job. The current This study has showed that the current knives used need improvement on the quality of the cable and lamina, in order to contribute to the worker´s comfort during the activity. It is possible that a knife, projected on this study can bring a higher comfort, satisfaction, productivity and prevent the discomfort, which can be an aggravating to the imminence of WRMD (work-related musculoskeletal disorders)