Effectiveness of Ergonomic Training to Decrease Awkward Postures during Dental Scaling Procedures: A Randomized Clinical Trial.

Studies demonstrate that there is a lack of effective ergonomic principles for adopting a neutral posture during the execution of dental procedures. ISO 11.226:2000 Standard, Corr. 1:2006 has been thoroughly evaluated and adapted to the way that dentists work by the European Society of Dental Ergonomics (ESDE). However, after 15 years, no studies that showed strong evidence of effectiveness in reducing the prevalence of awkward posture in applying its parameters within the scope of dental practice were found. The aim of this study was to verify the effectiveness of applying the ergonomic parameters proposed by the European Society of Dental Ergonomics (ESDE) and ISO 11226 in reducing the prevalence of the main awkward postures adopted by female dental surgeons during the execution of dental scaling on a dental mannequin. A randomized clinical trial was carried out with sixty dental surgeons randomly assigned to two groups: the intervention group, who received instructions and theoretical and practical ergonomic training; and the control group, who received the same training only at the end of the study. For data analysis, Software IBM SPSS 27 and RStudio was used. Descriptive statistics were performed to verify the effectiveness of the intervention, and generalized linear models (specifically, generalized estimated equation models) were used. Poisson distribution was carried out with log link function and network analyses. Sixty female dental surgeons participated in the study. Twenty-two were distributed in the intervention group and thirty-eight in the control group. It was found that ergonomic training enabled a 63% reduction in the prevalence of awkward postures and that there was a statistically significant difference (p < 0.001) only in the intervention group. The analyses showed that the estimated marginal means of postures not recommended in the groups' initial control, final control, initial intervention, and final intervention were 8.6, 8.2, 9.0, and 3.4, respectively. The relationship of networks analyses of the variables is shown with different profiles in the control and intervention groups, but the same pattern between the groups only vary in the strength and direction of the correlations. It was concluded that the ergonomic training based on the parameters of ISO 11226 and DIN EN 1005-4, and its adaptations to the dental practice provided by the European Society of Dental Ergonomics, as well as recent studies, contributed significantly to reducing the prevalence of awkward postures adopted by female dentists during the simulation of the basic periodontal procedures; however, it was not effective enough to improve the posture of the head and neck.

Evaluation of two wheelchair hand rim models: contact pressure distribution in straight line and curve trajectories.

Manual wheelchairs are essential for people with disabilities or limited mobility. However, manual propulsion causes biomechanical loads, including contact pressures on the palms of the hands. The hand rim design has received little attention over time, remaining almost unchanged since its creation. This study investigated how two different designs of such devices - one standard and another with a contoured design - influence the contact pressure on the surface of the hands. The procedures included a figure-of-eight shape propulsion task on a regular floor, using both models on a wheelchair. A pressure-mapping system coupled with a pair of fabric gloves recorded the data. The results show that the contoured hand rim provides lower pressure in most of the analysed regions. Considering that manual propulsion is performed during a considerable part of the day as a routine activity, improving the hand rim interface may benefit the user's comfort and safety during wheelchair use. Practitioner summary: The design of the hand rim used in wheelchair propulsion influences the contact pressure on the hands. Conventional round tube rims tend to concentrate high levels of pressure on the distal phalanges and metacarpal regions. A contoured design generally provides better stability and promotes the distribution of pressure. Abbreviations: AT: assistive technology; kPa: kilopascal.

Pessoa idosa com doença de Parkinson e a relação da usabilidade na interação com aviamentos de fechos presentes no vestuário / Older person with Parkinson's disease and aspects of usability in the interaction with clothing fasteners

O envelhecimento humano é cada vez mais pauta de estudos que avaliam doenças crônico-degenerativas e a interferência dessas na capacidade de execução de atividades de vida diária (AVDs). A doença de Parkinson (DP) é uma patologia cujos sintomas podem agravar a qualidade da performance em atividades diárias, principalmente quanto a déficits em movimentos manuais coordenados. No que tange aos aspectos de usabilidade na interação com produtos, em específico os de vestuário, percebe-se que até então pesquisas científicas não aprofundam as relações possíveis entre variáveis envolvidas nesse processo. Entre as variáveis, podem-se destacar as características de manipulação de força e desempenho associadas à percepção de esforço e desconforto gerados no ato de vestir-despir e se tais variáveis interferem no gênero e na situação de saúde na qual se encontram pessoas idosas. Pelo que se sabe até aqui, diferentes desenhos das interfaces podem influenciar negativamente a ação de abrir e fechar aviamentos de vestuários, limitando a autonomia em realizar essa AVD básica de forma independente. Logo, o objetivo principal do estudo foi compreender os aspectos do manejo de aviamentos de fecho, bem como a influência das perdas motoras e funcionais com base em atividades simuladas de uso, que possam esclarecer detalhes acerca da relação do usuário/atividade/produto. Com metodologia experimental, de caráter descritivo e exploratório, de natureza quantitativa e laboratorial, pode-se avaliar atividades com botões e zíperes. O estudo contou com 40 participantes, nos quais se verificou, por meio dos resultados alcançados, que as variáveis de força não influenciam o desempenho de manipulação de aviamentos de fecho e que os efeitos da DP interferem na má execução da atividade coordenada, comprometendo a completude. Também foi constatado que a diminuição do desempenho em manipular aviamentos de fecho e os desenhos dos artefatos influenciam negativamente a usabilidade em fechar e abrir botões e zíperes destacáveis. Cabe ressaltar que os resultados aqui encontrados fomentam a necessidade de conscientização das empresas do setor de vestuário para desenvolverem produtos que possam promover a independência e a satisfação do uso, permitindo contribuir com a vestibilidade na interação homem-atividade-produto.

There has been an increasing number of human aging studies evaluating chronic degenerative diseases and how they interfere with the ability to perform activities of daily living (ADLs). Parkinson's disease (PD) is a condition whose symptoms may deteriorate the quality of ADL performance, especially in terms of impaired coordinated hand movements. Regarding aspects of usability in the interaction with products, specifically clothing items, scholarly research has not yet delved into the possible relationships between variables involved in this process. The variables include characteristics of strength manipulation and performance associated with perceived effort and discomfort while dressing-undressing, and whether such variables are associated with gender and health status of older people. Different interface designs are known to possibly have a negative influence on the action of opening and closing clothing fasteners, limiting the autonomy to perform a basic ADL independently. Thus, the study primarily aimed to understand aspects of the management of clothing fasteners as well as the influence of motor and functional impairment based on simulation activities, which may clarify features of the user-activity-product relationship. An experimental method of descriptive, exploratory, quantitative, and laboratory nature was used to assess activities with buttons and zippers. The study included 40 participants and results showed that strength variables had no influence on the performance of manipulating clothing fasteners and that PD leads to poor performance in the coordinated activity, compromising its conclusion. Furthermore, poor performance in manipulating clothing fasteners and fastener design were found to negatively influence the ability to open and close detachable buttons and zippers. These results emphasize the need of raising awareness of clothing companies to the importance of developing products that can promote user independence and satisfaction, contributing thus to an improved user-activity-product interaction.

The influence of axle position and the use of accessories on the activity of upper limb muscles during manual wheelchair propulsion.

INTRODUCTION: Wheelchair configuration is an important factor influencing the ergonomics of the user-device interface and, from a biomechanical point of view, small changes in chair setup may have a positive influence on the demand on the upper limbs during manual propulsion. This study aimed to investigate the influence of the position of the rear wheels' axle and the use of accessories on the activity of upper limb muscles during manual wheelchair propulsion. METHODS: Electromyography signals of the biceps, triceps, anterior deltoids and pectoralis major were collected for 11 able-bodied subjects in a wheelchair propulsion protocol with four different wheelchair configurations (differing in axle position and the use of accessories) on a straightforward sprint and a slalom course. RESULTS: With accessories, moving the axle forward led to a decrease in the activity of all muscles in both the straightforward sprint (significant differences in triceps, anterior deltoids and biceps) and the slalom course (significant difference in anterior deltoids and biceps). However, when propelling the chair without accessories, no difference was found related to axle position. CONCLUSION: Changes in wheelchair configuration can influence the ergonomics of manual wheelchair propulsion. Reducing the biomechanical loads may benefit users' mobility, independence and social participation.

The influence of seat height, trunk inclination and hip posture on the activity of the superior trapezius and longissimus.

[Purpose] This study was aimed at investigating the influence of seat height and body posture on the activity of the superior trapezius and longissimus muscles. [Subjects and Methods] Twenty two healthy subjects were instructed to perform a total of eight different body postures, varying according three main factors: seat height (low and high seat); trunk inclination (upright and leaning forward at 45°); and the hips in abduction and adduction. Electromyography of the superior trapezius and longissimus was collected bilaterally, and the average values were obtained and compared across all the postures. [Results] The activity of the superior trapezius and longissimus significantly changes according to the seat height and trunk inclination. For both seat heights, sitting with trunk leaning forward resulted in a significant increase in the activity of both muscles. When sitting in a high seat and the trunk leaning forward, the superior trapezius activity was significantly reduced when compared to the same posture in a low seat. [Conclusion] This study contributes to the knowledge on the influence of the body posture and seat configuration on the activity of postural muscles. Reducing the biomechanical loads on the postural muscles must be targeted in order to improve users' comfort and safety.

Influence of door handles design in effort perception: accessibility and usability.

The application of ergonomics in product design is essential to its accessibility and usability. The development of manual devices should be based on ergonomic principles. Effort perception analysis is an essential approach to understand the physical and subjective aspects of the interface. The objective of the present study was to analyze the effort perception during a simulated task with different door handles by Portuguese subjects of both genders and different ages. This transversal study agreed with ethical aspects. 180 subjects of both genders pertaining to three age groups have participated. Five door handles with different shapes were evaluated. A subjective numeric rating scale of 5 levels was used to evaluate the effort. For statistical analysis it was applied the Friedman non-parametric test. The results have showed no significant differences of effort perception in door handles "A" and "B"; "A" and "D"; and "D" and "C". Door handle "E" presented the lowest values of all. In general, there's an inverse relationship between the results of biomechanical studies and the effort perception of the same task activity. This shows that door handles design influence directly these two variables and can interfere in the accessibility and usability of these kinds of products.

Usability of car stereo.

Automotive sound systems vary widely in terms of functions and way of use between different brands and models what can bring difficulties and lack of consistency to the user. This study aimed to analyze the usability of car stereo commonly found in the market. Four products were analyzed by task analysis and after use reports and the results indicate serious usability issues with respect to the form of operation, organization, clarity and quality of information, visibility and readability, among others.

Perceptual aspects of the use of faucets (taps).

This paper presents an assessment with simulated activities with the aim of analyzing the perception of ease / difficulty of the use of faucets (taps) handles by 180 Brazilian adults. Five different handles faucets were activated for subsequent collection of perceptual data. The procedures were based on main recommendations for biomedical ethics and human research. The results indicate that handles with levers are significantly (p ≤ 0.05) easier to use. The most difficult are characterized by not having support points for the rotation (levers) or more points of pressure concentration in the hand.

Product functions: interfaces with ergonomic design.

In addition to technical quality, increasing emphasis is being placed on the importance of elements such as the appearance and meaning of products. To be successful, therefore, attention must be paid to the aesthetic and symbolic functions of objects as well as to reliability and physical quality. Study of the interfaces of these functions may provide a theoretical basis for the ergonomic design of products. The objective of this review is to attempt to establish the nature of these interfaces.

Openability of soft drinks PET packagings.

Studies on packaging accessibility are still incipient in Brazil. Many of these packagings can represent a challenge to users, whether due to non-informative labels, tricky tabs or seals, or even those that need strength to open. This paper brings a simple test to determine the necessary torque force to open PET bottles, and to predict the amount of users that could not open it. The findings suggest that a considerable amount of users could not open it or would have some difficulties to exert the necessary force.

Assento adaptável para portadores de paralisia cerebral e sequela de escoliose: estudo de caso aplicando design ergonômico / Adaptable seat to people with cerebral palsy and scoliosis: ergonomic design a case report

O desvio da coluna vertebral do tipo escoliose é uma das principais sequelas da paralisia cerebral (PC). A intervenção projetual com aplicação dos princípios do design ergonômico, de modo a avaliar e validar técnicas clínicas e fisioterapêuticas na utilização de assentos especiais para reabilitação, foi o objetivo proposto neste estudo, particularmente através de um assento modular com regulagem vertical, buscando prevenir e minimizar os probelmas decorrentes desse acometimento. Métodos: Abordagens éticas foram consideradas para os tres indivíduos portadores de PC e escoliose, sendo que apenas um deles utilizou o assento adaptado com regulagem vertical, enquanto os demais fizeram uso de assentos comuns. Os procedimentos envolveram avaliações pré e pós-uso do produto, num intervalo de 90 dias considerando análises psicológicas de atividades diárias (AVDs), neurológica, ortopédica, radiológica, além do método da Biofotogrametria Computadorizada. Resultados: Foram encontrados resultados positivos, principalmente no que diz respeito ao paciente que fez uso do assento adaptado, evidenciando melhorias nos vários aspectos avaliados. A análise demonstrada pela Biofotogrametria Computadorizada foi significativa para as condições posturais da coluna vertebral nesse paciente (p d 0,010). Discussão e Conclusão: A eficiência do assento modular com regulagem vertical foi comprovada, sugerindo uma nova alternativa para melhor qualidade de vida desses pacientes, e contribuindo expressivamente para as metodologias do design ergonômico.

A interface tecnológica nas atividades ocupacionais dos cirurgiões-dentistas: uma abordagem do designer ergonômico / Technological interface in the dentist's professional activities: ergonomics design boarding

O desenvolvimento da Odontologia tem se caracterizado pelo emprego de novos materiais e tecnologias de tratamento, e pro uma atividade ocupacional mais intensiva. As condições biomecânicas decorrentes dessa atividade podem favorecer o surgimento de DORTs (disturbios osteo-musculares relacionados ao trabalho). estudos com cirurgiões dentistas apontam vários problemas ocupacionais, muitos relacionados à