This wide-ranging study explored various parameters of visual search in relation to computer screen displays. Its ultimate goal was to help identify factors which could result in improvements in commercially available displays within the 'real world’. Those improvements are generally reflected in suggestions for enhancing efficiency of locatabolity of information through an acknowledgement of the visual and cognitive factors involved. The thesis commenced by introducing an ergonomics approach to the presentation of information on VDUs. Memory load and attention were discussed. In the second chapter, literature on general and theoretical aspects of visual search (with particular regard for VDUs) was reviewed. As an experimental starting point, three studies were conducted involving locating a target within arrays of varying configurations. A model concerning visual lobes was proposed. Two text-editing studies were then detailed showing superior user performances where conspicuity and the potential for peripheral vision are enhanced. Relevant eye movement data was combined with a keystroke analysis derived from an automated protocol analyser. Results of a further search task showed icons to be more quickly located within an array than textual material. Precise scan paths were then recorded and analyses suggested greater systematicity of search strategies for complex items. This led on to a relatively 'pure' search study involving materials of varying spatial frequencies. Results were discussed in terms of verbal material generally being of higher spatial frequencies and how the ease of resolution and greater cues available in peripheral vision can result in items being accessed more directly. In the final (relatively applied) study, differences in eye movement indices were found across various fonts used. One main conclusion was that eye movement monitoring was a valuable technique within the visual search/VDU research area in illuminating precise details of performance which otherwise, at best, could only be inferred.

Low back pain (LBP) is a common condition that affects all age groups and sexes. Although the development of LBP is multifactorial, the performance of lifting-based manual material handling (MMH) tasks are recognized as a primary risk factor. Many occupations that involve MMH tasks are performed in hazardous environments, where personal protective equipment (PPE) must be worn. Among the most commonly prescribed forms of PPE in Canada are CSA Grade 1 steel-toed work boots. According to the hazards present on the jobsite, workers may need to wear steel-toed work boots with/without a metatarsal guard or be able to wear steel-toed shoes (no upper). However, the amount of research on the interaction between protective footwear and human motion is limited. Therefore, the purpose of this thesis was to assess the effects of steel-toed shoes (unlaced), steel-toed boots (work boot), and steel-toed boots with a metatarsal guard (MET) on lifting mechanics. Specifically, three-dimensional kinematics of the lower limbs and trunk, sagittal net reaction moments of the low back, and local dynamic stability (LDS) of the lower limbs, lower back, and upper back were analyzed. Twelve males and 12 females were recruited to participate in this research project. Participants performed a repetitive lifting task at 10% of their maximum back strength, under three block-randomized footwear conditions. Ankle dorsiflexion was negatively affected by footwear type, where dorsiflexion was reduced the most in the MET condition compared to the unlaced condition (p < 0.01). However, there were no other main effects of footwear type on any other variable tested, and both male and female participants were able to maintain similar lifting mechanics and LDS values when moving up the kinematic chain. It is possible that participants were able to preserve their kinematics and stability through the appropriate recruitment of muscles, which may have implications for an increase in compressive and shear force on the spine and should be explored further in the future.

Orientadores: Roberto Funes Abrahão, Mauro José Andrade Tereso / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-19T17:40:16Z (GMT). No. of bitstreams: 1 Almeida_SimoneFormigoni_M.pdf: 5379139 bytes, checksum: fb6b1d345b6c3d48606e4bfd88ec9a8f (MD5) Previous issue date: 2011 / Resumo: A colheita florestal mecanizada tem sido objeto de estudos ergonômicos no Brasil e no exterior, onde as pesquisas focam na avaliação de aspectos dimensionais e de usabilidade das máquinas de colheita disponíveis no mercado, visando a melhoria dos projetos e da segurança e saúde dos operadores. Entretanto, ainda são poucas as pesquisas direcionadas ao operador em particular e aos diversos aspectos que compõem sua tarefa. Este trabalho buscou ampliar os conhecimentos sobre a tarefa do operador de máquinas de colheita florestal, em particular os operadores das máquinas Feller-Buncher, Skidder e Garra Traçadora. Também teve por objetivo quantificar os níveis de vibração linear a que estes operadores ficam expostos durante a jornada de trabalho. Foi realizada uma Análise Ergonômica do Trabalho durante onze meses, através de visitas ao campo, fotos, filmagens e entrevistas, além das informações obtidas através de questionário, visando caracterizar a população envolvida, bem como conhecer a opinião desses trabalhadores sobre as máquinas e a tarefa. As medições dos níveis de vibração linear com três graus de liberdade foram realizadas com a utilização do acelerômetro piezoelétrico instalado no assento dos três modelos de máquinas e um medidor integrador de vibração triaxial, de acordo com as normas internacionais ISO 2631-1:1997, no critério saúde, e da Diretiva 2002/44 da Comunidade Européia. As medições dos níveis de vibração apontaram que, tanto o Skidder quanto o Feller- Buncher apresentaram níveis acima das recomendações da norma ISO e o Nível da Ação do Valor Limite de Exposição (NA/VLE) para as duas máquinas se mostraram acima das recomendações da diretiva européia 2002/44. A Garra Traçadora apresentou os menores níveis vibratórios, embora o NA/VLE esteja acima do recomendado pela diretiva européia. A tarefa do operador de máquina de colheita florestal mostrou-se bastante complexa e de alta exigência cognitiva e motora. Apesar da sofisticação tecnológica das máquinas de colheita florestal, ainda há muito que melhorar quanto às vibrações mecânicas a que estão sujeitos os operadores / Abstract: Mechanized logging has been the subject of ergonomic studies in Brazil and abroad, with research focused on evaluation of dimensional aspects and the usability of logging equipment on the market aimed at improving projects and the health and safety of operators. However, there has been little research directed specifically to the operator and the various aspects of his activities. This study aimed to expand the knowledge about the operator's activities with logging equipment, specifically operators of Feller-Buncher Buncher, Skidder and Slash Grapple machines. It has also sought to quantify the linear vibration levels that these operators are exposed to during the workday. An Ergonomic Analysis was performed for eleven months, through field visits, photos, video footage and interviews, as well as information obtained through a questionnaire, in order to characterize those involved, and understand the opinion of these workers regarding their equipment and their job. Linear vibration level measurements with three degrees of freedom were performed using the piezoelectric accelerometer fitted on three machine models and a meter integrator of triaxial vibration, in accordance with international standards ISO 2631-1:1997, health criteria, and the 2002/44/EC. Measurements of vibration levels indicated that both the Skidder and Feller-Buncher had levels above ISO recommendations and the Exposure Action and Limit Values (EAV / ELV) for the two machines were above the recommendations of the 2002/44/EC. The Slash Grapple machine showed the lowest vibrational levels, although the EAV / ELV was above that recommended by the European policy. The operator's activities with logging equipment proved to be very complex, requiring highly demanding cognitive and motor skills. Despite the technological sophistication of logging equipment, there is still much room for improvement with regard to the effects of mechanical vibration on their operators / Mestrado / Planejamento e Desenvolvimento Rural Sustentável / Mestre em Engenharia Agrícola

Lower extremity muscle activity during balance can be affected by footwear characteristics. A dearth in literature remains regarding minimalist footwear in combination with a military-type workload on muscle activation during balance. The purpose of the study was to assess lower extremity muscular activity during balance tasks before and after a military workload, in two military footwear [standard tactical (STD), minimalist (MIN)]. Twentyour trained males (18-35 years) participated, following a repeated measures counter balanced footwear assignment. Participants performed maximal voluntary contractions (MVC) and balance assessments before and after a military treadmill workload. Muscle activity was collected on tibialis anterior, medial gastrocnemius, tibialis posterior, and peroneus-longus. A repeated measures 2x2 [2(Boot #1 x Boot #2) x 2(Pre-test x Post-test)] RM ANOVA with alpha set at 0.05. Significant differences occurred in mean, root-mean square, and peak muscle activities and in %MVC and co-contraction index, that were attributed to footwear design and physiological workload.

Neuroergonomics, the application of neuroscience to human factors and ergonomics, is an emerging science focusing on the human brain concerning performance at work and in everyday settings. The advent of portable neurophysiological methods, including electroencephalography (EEG), has enabled measurements of real-time brain activity during physical tasks without restricting body movements. However, the EEG signatures of different physical exertion activity levels that involve the musculoskeletal system in everyday settings remain poorly understood. Furthermore, the assessment of functional connectivity among different brain regions during different force exertion levels remains unclear. One approach to investigating the brain connectome is to model the underlying mechanism of the brain as a complex network. This study applied employed a graph-theoretical approach to characterize the topological properties of the functional brain network induced by predefined force exertion levels, namely extremely light (EL), light (L), somewhat hard (SWH), hard (H), and extremely hard (EH) in two frequency bands, i.e., alpha and beta. Twelve female participants performed an isometric force exertion task and rated their perception of physical comfort at different physical exertion levels. A CGX-Mobile-64 EEG was used for recording spontaneous brain electrical activity. After preprocessing the EEG data, a source localization method was applied to study the functional brain connectivity at the source level. Subsequently, the alpha and beta networks were constructed by calculating the coherence between all pairs of 84 brain regions of interests that were selected using Brodmann Areas. Graph -theoretical measures were then employed to quantify the topological properties of the functional brain networks at different levels of force exertions at each frequency band. During an 'extremely hard' exertion level, a small-world network was observed for the alpha coherence network, whereas an ordered network was observed for the beta coherence network. The results suggest that high-level force exertions are associated with brain networks characterized by a more significant clustering coefficient, more global and local efficiency, and shorter characteristic path length under alpha coherence. The above suggests that brain regions are communicating and cooperating to a more considerable degree when the muscle force exertions increase to meet physically challenging tasks. The exploration of the present study extends the current understanding of the neurophysiological basis of physical efforts with different force levels of human physical exertion to reduce work-related musculoskeletal disorders.

Society is becoming increasingly digitalized and we spend more and more of awake hours infront electronics, both at home and at work. Our bodies, made for being resilient hunters, are not suited for sitting still an entire day. The static work exhausts the muscles and makes it hard to maintain a correct posture throughout the day, enough time in static positions may result in both interior and exterior damages to the body. The main purposes with the project is to increase the awareness of what horrible consequences that may occur when the body is being exposed to an unhealthy posture, also develop a prototype for a product that will guide the user on the road of getting a better default posture.The product we have developed is primarily aimed at companies, which it will be able to offer their employees a better shot at a healthier life, which will result in reduced number of sick leaves for the companies. We, Johan Norén and Lukas Persson, has in our thesis, HållRätt, developed a prototype for a product that will assist you by encouraging you to improve your posture reduce your chances of getting unwanted injuries. The product is a wearable accessory that will be undetectable by your surroundings, unless you choose to wear over your clothes. The product will be a combination of a helper and personal trainer who will guide the user on the way to a better posture and thus better health and a fuller life.

The rapid growth of unmanned aircraft system (UAS) use in both the military and civil sectors has uncovered an array of challenges within the field. In terms of human factors and ergonomics, the influence of the unique physical design of the control stations used to pilot the unmanned aircraft on local muscular fatigue and discomfort are of great concern. This study was conducted to assess the influence of two display configurations, Side-by-Side (SS) and Stacked (ST), and two chairs, Ergonomic (EC) and Captain’s (CC), on mean and median power frequencies, root mean square amplitude, posture, discomfort, workload, and seat pressure. Sixteen participants [age: 24.75 ± 2.96 years; gender: 4 female/ 12 male; height: 177.56 ± 9.09 cm; weight: 81.37 ± 16.43 kg] completed four, 2-hour simulated UAS flights for all chair/display combinations. Eight participants piloted one, 6-hour simulated UAS flight in the display/chair combination which best minimized discomfort and fatigue in the two-hour flights, EC/SS. During the two-hour flights, muscle activity, discomfort, posture, workload, and seat pressure findings indicated increased muscular fatigue and discomfort over time. Generally, the EC/SS condition appeared to best mitigate muscular fatigue and postures associated with increased risk for the development of musculoskeletal disorders. Six-hour flight data failed to provide additional insights on the influence of extended duration flights on the dependent variables of this study. Finally, linear regression analysis revealed muscle activity can likely be predicted during UAS piloting tasks using the dependent variables in this study; however, the study failed to provide evidence that models built from two-hour data can accurately predict muscle activity out to six hours.

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My journey from an over-practice injury to the final exam concert on a master level. I start with my background and with investigating the possible reasons for my injuries, then continue with providing solutions to my problems. The solutions consist of technical advice, knowledge of ergonomy, information on the Alexander Technique, Feldenkrais and the psychological factors. The goal of this thesis was to manage to perform the Tchaikovsky Violin Concerto and get away from that experinece without renewing my injury.

International Telemetering Conference Proceedings / October 22-25, 1984 / Riviera Hotel, Las Vegas, Nevada / The processing power afforded by embedded microcomputers in state-of-the-art control applications offers the design engineer greatly expanded opportunities for improved ergonomic design, even without the use of “soft” actuator and/or display devices (which are sometimes undesirable and/or unacceptable). Especially important is the exploitation of software to simplify the hardware design while simultaneously implementing decision/mode logic that would be prohibitively expensive if done in hardware alone. The designer is often confronted with an ocean of possibilisties, and must make intelligent decisions in order to satisfy increasingly demanding applications and sophisticated users. The design decisions and resulting features and behaviors of an automatic antenna control unit are discussed from the operators point of view (black box), but also with the intention to detail some of the logic necessary to implement these features. This is prefaced by a discussion of the characteristics of the primary operator interface, the front panel, and the factors that influenced its design. Areas for future improvement of the design are also mentioned.