Dissertations / Theses on the topic 'Biomechanical limits'

This diploma thesis deals with the normative requirements on the activities of restraint systems. It includes biomechanical limits of the human body, restraint systems, description of the principle of their action and legislation. Legislation, particularly regulations of ECE and EC directives defines the normative requirements on the activity of restraint systems in the context of the approval process. There are described two types of restraint systems: seat belts and airbags in details. There are created simulations of crashtests and reviewed influence of using restraint systems on elimination of negative phenomenon of car accidents.

Individuals, post-stroke, present with an array of changes to the neuromuscular system function such as muscle weakness and abnormal muscle activation patterns. Different combinations of these and other altered body functions result in limitations in functional mobility, such as reduced gait speed and high risk for falls. In this series of studies, I developed a deeper understanding of how neuromechanical factors may limit the fastest speed that an individual post-stroke can reach before they are unable to move any faster without losing balance. I conducted three studies. In the first study, my results showed that, after stroke, individuals have the capacity to walk at faster speeds than their overground self-selected maximum walking speed, while walking on a treadmill and when provided horizontal assistance using a robotic device. In the second study, I showed that non-impaired individuals modulated the amplitude and phasing of muscle activity according to the requirements brought about by the existence of horizontal assistive forces during walking at progressively faster speeds. Finally, in the third study I showed that individuals post-stroke also were able to modulate amplitude and phasing of muscle activity in both legs, according to the requirements brought about by the existence of horizontal assistive forces during walking at progressively faster speeds. However, the paretic leg was more responsive to horizontal assistive forces than the non-paretic leg. The understanding gained through these studies provide novel insights regarding the capabilities of individuals with post-stroke hemiparesis to adapt their existing impaired neuromuscular mechanisms into more challenging walking tasks. Each study leads to ideas for the development of potentially more effective rehabilitation protocols targeted at the modulation of amplitude and phasing of muscle activity in order to safely achieve faster walking speeds.

Baigiamajame magistro darbe yra atliekamas apatinių galūnių įtvarų ilgaamžiškumo tyrimas. Yra iškeliama čiurnos sąnario įtvarų patvarumo problema ir sudaroma jos sprendimo metodika. Darbe yra atliekama čiurnos sąnario biomechanikos analizė, įtvarų konstrukcijų ir medžiagų analizė, nagrinėjama ilgaamžiškumo reikšmė ir tyrimo būdai. Sudaroma tyrimo metodika. Kompiuterinio modeliavimo būdu, panaudojant SolidWorks programinę įrangą, yra sudaromas įtvaro modelis, nustatomos veikiančios apkrovos, atliekami įtempių ir poslinkių pasiskirstymo tyrimai. Atliekami modelio nuovargio bandymai. Atsižvelgiant į tyrimų rezultatus, yra sudaromi įtvarų iš aukštos temperatūros plastikų tinkamo pritaikymo nurodymai. Pateikiamos išvados ir literatūros sąrašas.
Final thesis presents the research of durability of lower limbs splints. The problem of fatigue behaviour of ankle joint splint is raised and its solution is suggested. Final thesis contains ankle joint biomechanics analysis, lower limbs splints design and material analysis. Review of durability research methods is also done. The methodology of research is arranged. Using the computer aided modeling with SolidWorks software the model of ankle joint splint is created. Load parameters are determined, research of stresses and deformations are performed. Fatigue test is also performed. Due to the results of research, the instructions for ankle joint splints made of high density polyethylene and polypropylene use and adaptation are listed. Final thesis also contains conclusions and list of literature. Size of work – 77 pages of text without attachments, 55 pictures, 9 tables and 25 bibliographical sources.

INTRODUCTION: Tightness of the hip flexor muscle group may contribute to altered sagittal plane kinematics of the lumbo-pelvic-hip (LPH) complex during dynamic movements. Therefore, the purpose of this study is to analyze the effects of a three-week home-based stretching program on passive hip extension (PHE), as well as on active hip extension (AHE), anterior pelvic tilt (APT), and lumbar spine extension (LSE) when running. METHODS: Twenty healthy subjects with limited PHE underwent a 3D gait analysis both prior (PRE) and following (POST) a three-week static hip flexor stretching program. RESULTS: Following the stretching program, peak PHE increased significantly (P < 0.001), while no significant improvements were reported in AHE, APT, or LSE. In addition, no relationship was found between the change in PHE with either the change in AHE, APT, or LSE. Finally, a high relationship was observed between AHE and APT during running (r = 0.83, p < 0.001), and low relationships were observed between APT and LSE (r = -0.41, p = 0.08) and AHE and LSE (r = -0.34, p = 0.15). CONCLUSION: A three-week static stretching program of the hip flexor musculature resulted in an increase in PHE, but the sagittal plane kinematics of the LPH complex during running remained unchanged. The correlations observed between AHE, APT, and LSE suggest there is a kinematic relationship between the hip, pelvis, and spine.

Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Thomas J. Burkholder; Committee Member: Lena H. Ting; Committee Member: Roman O. Grigoriev; Committee Member: Shawn Hochman; Committee Member: T. Richard Nichols.

Objective- To compare the biomechanical properties of 3.5 locking compression plate (LCP) fixation to 3.5 limited contact dynamic compression plate (LC-DCP) fixation in a canine cadaveric, distal humeral metaphyseal gap model in static axial compression and cyclic axial compression and torsion. Study Design- Biomechanical in vitro study. Sample Population- 30 paired humeri from adult, medium to large breed dogs. Methods- Testing was performed monotonically to failure in axial compression on ten pairs of humeri, cyclically in axial compression for 10,000 cycles on ten pairs and cyclically in torsion for 500 cycles on the last ten pairs. Results- Humeral constructs stabilized with LCPs were significantly stiffer than those plated with LC-DCPs when loaded in axial compression (P=0.0004). When cyclically loaded in axial compression over 10,000 cycles, the LC-DCP constructs were significantly stiffer than those constructs stabilized with LCPs (P=0.0029). Constructs plated with LC-DCPs were significantly more resistant to torsion over 500 cycles than those plated with LCPs (P<0.0001), though no difference was detected during the first 280 cycles. Conclusions- The increased stiffness of LCP constructs in monotonic loading compared to constructs stabilized with non-locking plates may be attributed to the stability afforded by the plate-screw interface of locking plates. The LCP constructs demonstrated less stiffness in dynamic testing in this model, likely due to plate-bone offset secondary to non-anatomic contouring and occasional incomplete seating of the locking screws when using the torque-limiting screw driver. Clinical Relevance- LCPs yield less stiff fixation under dynamic loading than conventional LC-DCPs when applied to severely comminuted, metaphyseal fractures. Improving anatomical contouring of the plate and insuring complete screw insertion into the locking plate hole may improve stiffness when using LCPs in comminuted fractures.
Master of Science

Through whatever misfortune people have always had the need for artificial limbs. This study questions current thinking in the field of prosthetics, aiming to address the most prevalent issues affecting the amputee today, such as, fit, comfort and practicality, which have an inarguable baring on patient prostheses satisfaction. Through examination, more obscure problems encountered by users were explained, indicating how design issues and methodologies affect the present and future manufacturing process. As a result of this research a development model for the increased effectiveness of prostheses fitrnent and improvements in patient prosthetic satisfaction have been made. This has included suggestions for potential improvements in limb fitting center protocol, patient education and awareness strategies for the assessment of delivered patient needs and requirements Methods implemented during the research consisted of a comprehensive literature review of current infonnation, technical reports and patient satisfaction findings and assessment techniques. 1bis was accompanied with an investigation and evaluation of the prosthetics industry, including limb fitting, patient requirements, product/service shortfalls, rehabilitation technique and patient lifestyle. Additionally interviews and questionnaires with practitioners and users were undertaken aiding the evaluation of patient satisfaction and the identification of potential improvements in artificial limb fitment procedure. The results revealed several areas that deserved more detailed investigation, notably relating to the hypotheses, that the relationship between the levels of fit, comfort and practicality archived within the prostheses has an effect on the patient's satisfaction. Through the examination ofthis main hypothesis one of the most significant factors which emerged was the effect ofthe communication level held between the patient and prosthetist. The results of"this enquiry indicated that improved patient knowledge with respect oftheir situation and an increased ability to accurately relay issues of concern to the prosthetist, facilitated the delivery of satisfactory prostheses, in turn improving its fit, comfort and practicality. In conclusion, previous conjecture as to the limited effectiveness of current prosthetics in re-establishing patients activity levels were assessed, and suggestions generated by the results of patients dissatisfaction with their limbs. These findings facilitated the realisation of new educational, protocol-based methodologies, tools and theories.

Embora a analise no domínio da freqüência do sinal Eletromiográfico (EMG) seja empregada na caracterização do processo de fadiga muscular localizada sua aplicação, especificamente a da Freqüência Mediana (Fmed), é pouco explorada para a determinação do Limiar de Fadiga Eletromiográfico (LFE). Neste estudo foram realizadas análises baseadas em procedimentos experimentais executados em três diferentes modalidades de exercício: i) isométrico; ii) isotônico com peso fixo; iii) isotônico no cicloergômetro; onde foi monitorado o comportamento da Fmed do sinal EMG em três porções do músculo quadríceps femoral: vasto lateral, vasto medial e reto femoral. Os resultados demonstraram ser possível determinar o LFE através da monitoração da Fmed, em qualquer modalidade de exercício para todas as três porções musculares avaliadas. Entretanto, para o exercício isométrico e isotônico com peso fixo a qualidade dos ajustes, utilizados para o calculo do LFE, apresentou melhores índices estatísticos em comparação com os resultados obtidos no cicloergômetro. Pode ser considerado um reflexo deste comportamento a menor variação nos valores do LFE observada nas duas primeiras modalidades de exercício. Por conseqüência, nestas modalidades, uma melhor caracterização do LFE, relacionada sua definição teórica, foi observada. A análise complementar das bandas de freqüência isoladas demonstrou a possibilidade de melhoramentos relacionados ao processo metodológico de tratamento do sinal EMG para determinação do LFE. Entende-se que a determinação do LFE é uma temática controversa, porém ao mesmo tempo apresenta um grande potencial de exploração científica caracterizando, neste contexto, a contribuição deste estudo para a área
Tthough the analysis in the frequency domain of the Electromyographic Signal (EMG) was used in the characterization of the localized muscular fatigue process their application, specifically the Median Frequency (MF), is rarely explored for the determination of Electromyographic Fatigue Threshold (EMGFT). In this study analysis based in experimental procedures were executed in three different modalities of exercise: i) isometric; ii) dynamic with fixed load; iii) dynamic in the cycle ergometer; where was monitored the behavior of the EMG signal through the MF in three portions of the quadriceps muscle: vastus lateralis, vastus medialis and rectus femoris. The results demonstrated that the determination of EMGFT through the monitorization of MF was possible, in any modality of exercises for all the three muscular portions evaluated. However for the isometric and dynamic exercise with fixed load the quality of the adjustments, used for estimate the EMGFT, presented better statistical index in comparison with the results obtained in the cycle ergometer. May be considered a reflex of this behavior the smallest variation in the values of EMGFT observed in the first two modalities of exercise. For consequence, in these modalities, a better characterization of EMGFT was observed when related with your theoretical definition. The complemental analysis of the isolated bands of frequency demonstrated the possibility of improvement related in the methodological process of EMG signal processing for determination of EMGFT. The understanding around the determination of EMGFT demonstrated a controversial theme, however at the same time it presents a great potential of scientific exploration characterizing, in this context, the contribution of present study for this area

Orientador: Ricardo Machado Leite de Barros
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica
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Resumo: A marcha humana é um movimento complexo que integra todos os segmentos corporais. Ela é objeto de pesquisa em laboratórios de todo o mundo e nestes o principal protocolo adotado, protocolo Helen Hays, analisa apenas o movimento dos membros inferiores e pelve e, através da interpretação dos resultados, muitos procedimentos invasivos e/ou conservadores podem ser prescritos. O objetivo geral deste trabalho é propor, avaliar e aplicar modelos de representação biomecânica dos membros superiores e escápula visando a análise de marcha. Um segundo objetivo é integrar os modelos propostos ao protocolo experimental para análise de marcha descrito por ANDRADE (2002). O corpo humano foi modelado como um sistema de quinze corpos rígidos articulados, cada um representando um segmento corporal. A cada segmento foi associado um sistema de coordenadas e a posição e a orientação relativas entre dois segmentos foram descritas, respectivamente, pela translação entre suas origens e pela rotação entre as bases a eles associadas. Os modelos de representação do braço e escápula adotados neste trabalho seguem a recomendação da Sociedade Internacional de Biomecânica. Foram avaliados três voluntários do sexo feminino, sem histórico de patologias ou comprometimento da marcha e dois voluntários do sexo masculino portadores de Paralisia Cerebral Diplégica. Os resultados foram avaliados a partir de testes de acurácia em relação à reconstrução da trajetória de dois marcadores durante a marcha e a acurácia encontrada foi de 2,4mm em um volume calibrado de 4,5m3, o que garantiu a confiabilidade dos resultados. Considerando um ciclo de marcha do membro inferior esquerdo observou-se, nos voluntários normais, que durante a fase de apoio, o ombro direito apresentou aumento da adução, extensão e rotação interna. Durante a fase de balanço, os ângulos mencionados diminuíram. O ombro esquerdo apresentou comportamento simétrico relacionado ao ciclo de marcha. Em relação ao cotovelo, os ângulos de abdução-adução e rotação internaexterna permaneceram constantes em ambos os lados. Um sinal claro de flexão pode ser observado durante todo o ciclo. A análise proposta foi capaz de identificar e caracterizar os padrões de marcha dos voluntários normais. Em relação aos voluntários patológicos, um paciente apresentou um padrão de marcha em crouch e ele revelou um comportamento aproximadamente simétrico considerando os membros superiores do lado direito e esquerdo. O outro paciente apresentou rotação interna aumentada no quadril e pé esquerdo associado a uma rotação do tronco para o lado direito. O cotovelo e o ombro do lado direito apresentaram pequena mobilidade provavelmente para compensar a rotação do tronco para este lado. Os resultados obtidos a partir do protocolo proposto para os sujeitos normais e patológicos foram compatíveis com os dados da literatura em relação aos ângulos articulares dos membros inferiores e da pelve. Os resultados da movimentação dos membros superiores, escápula, tronco e cabeça dos voluntários com e sem alterações da marcha também mostraram coerência com a movimentação esperada pela análise visual e com os dados disponíveis na literatura.
Abstract: The human gait is a complex movement that integrates all body's segments. It is studied in various gait laboratories where the main protocol adopted is the Helen Hays protocol, which considers only the lower limbs and the pelvis movement. With the results obtained from this protocol, respective procedures are prescribed. The aim of this paper is to propose, evaluate and apply models of biomechanical representation of the upper limbs and the scapula, focusing on the gait analysis. The second aim is to integrate the proposed models to an experimental protocol for the gait analysis described by ANDRADE (2002). The human body was modeled as a system of fifteen articulated rigid bodies, each one representing a corporal segment. Each segment was associated to a coordinated system, and the relative position and orientation between two segments were described, by the translation between its origins and the rotation between the bases associated to them. The representation models of the arm and scapula adopted in this paper follow the recommendation of the International Society of Biomechanics. Three female volunteers without gait pathologies and two spastic diplegic cerebral palsy male patients were analyzed. The results were evaluated from the tests of accuracy in relation to the reconstruction of the trajectory of two markers during the gait. The accuracy found was of 2,4mm in a calibrated volume of 4,5m³, thus guarantees the reliability of the results. Considering a left lower limb gait cycle during the stance phase, the right shoulder presented increasing adduction, extension and internal rotation, while during the swing phase these angles decreased. The left shoulder presented a symmetrical behavior related to the gait cycle. Regarding the elbow, the abductionadduction and internal-external rotation angles remain approximately constant in both sides. A clear signal of flexion can be observed during the cycle. The proposed analysis was able to identify and characterize the normal gait patterns of the normal studied subjects. Regarding the pathological subjects, one patient presented a crouch pattern gait and an approximately symmetrical gait by considering the right and left upper limbs. The other patient presented increased internal rotation on the left hip and in the left foot associated to a right rotation of the trunk. The right shoulder and elbow joints have small mobility, probably to compensate the increased rotation of the trunk to this side. The results obtained from proposed protocol for normal and pathological subjects were compatible with literature results concerning lower limbs and pelvis angles. The upper limbs, scapula, trunk and head results from volunteers without and with gait pathologies were coherent with their articulated motion in relation to visual analysis and to another published studies.
Universidade Estadual de Campi
Biodinamica do Movimento Humano
Mestre em Educação Física

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The amputee patient undergoes several changes after the amputation, not only physical but also emotional and socioeconomic, requiring the use of prosthesis. One of the physical changes that affects the amputee's gait when using your prosthesis ambulation is compromised. The march is the natural way that humans use to move from one location to another. The march is a complex activity because it depends on a series of interactions between the two lower limbs multithreaded and total body mass. Therefore, assessing the impact of the use of prostheses in locomotor through the analysis of strategies for startup of the march transtibial amputees. We evaluated the speed and displacement of the COP, knee and ankle angles of the support member during initialization of the march. For the kinematic analysis was set 34 markers on anatomical landmarks of interest, two AMTI force platforms. For statistical analysis we used the Student t test and correlation between variables. Difference was only statistically significant variables in the knee angle and average speed side. The absence of a flexible ankle joint may result in limitations in the function of the prosthesis. Amputees to achieve an adequate control in propulsion and balance it was necessary to use several strategies to adjust. The prosthesis provided by SUS serves its purpose, which is to provide a walking person. But this improvement in the ankle joint can facilitate the process of walking boot. Another fact of great importance is the frequent evaluation of prosthetic to verify the necessary adjustments of the prosthesis.
O paciente amputado sofre várias alterações após a amputação, não somente físicas, mas também emocionais e socioeconômicas, sendo necessário que a utilização de prótese. Uma das alterações físicas que acomete o amputado é a locomoção quando da utilização de prótese a sua deambulação fica comprometida. A marcha é o meio natural que o ser humano utiliza para se deslocar de um local para outro. A marcha é uma atividade complexa porque depende de uma série de interações entre os dois membros inferiores multissegmentados e a massa total do corpo. Assim sendo, avaliar o impacto da utilização de prótese no aparelho locomotor por meio da análise das estratégias de inicialização da marcha em amputados transtibiais. Foram avaliados a velocidade e deslocamento do COP, ângulos do joelho e tornozelo do membro de apoio durante a inicialização da marcha. Para a análise cinemática foi fixado 34 marcadores em pontos anatômicos de interesse, mais duas plataformas de força AMTI. Para a análise estatística foi utilizado o test t de Student e a correlação entre as variáveis. Foi encontrada diferença estatística somente nas variáveis ângulo do joelho e velocidade médio lateral. A ausência de uma articulação do tornozelo flexível pode resultar em limitações na função da prótese. Os amputados para alcançar um adequado controle na propulsão e equilíbrio houve a necessidade a utilização de várias estratégias de ajustamento. A prótese fornecida pelo SUS atende o seu propósito, que é fornecer uma deambulação ao indivíduo. Porém a melhoria desta na articulação do tornozelo pode facilitar o processo de inicialização da marcha. Outro fato de grande importância é a freqüente avaliação do protetizado a fim de verificar os ajustes necessários da prótese.

AbstractIntroduction: Hand Arm Risk Assessment Method (HARM) is a tool to assess the risks of deve­lo­ping complaints of the arm, neck or shoulders during manual work. The method was developed in the Netherlands primarily for employers, but is also used as an aid to work environment in­spec­tors. The purpose of this study was to evaluate the HARM-method for assessment of biomecha­nical exposure of the upper limbs when performing manual tasks as well as its suitability to be used within work environment inspection. Methods: Ten labour inspectors conducted assessments of five video-recorded work tasks. Assess­ments made with HARM were compared with those made with the Assessment of Re­pe­titive Tasks (ART) tool and with ACGIH Hand Actvity Level (HAL) - both methods for assess­ment of bio­mecha­nical exposure of the upper limbs - and with the model for the assessment of re­pe­titive work in the pro­visions of the Swedish Work Environ­ment Autho­rity on ergonomics for the prevention of mus­culo­skeletal disorders, AFS 1998:1. HAL is based on a threshold limit value for hand activity. The method combines the assessment of hand activity with per­ceived effort in the hand and forearm. The assess­ments were made twice, two weeks apart. Following each assessment the inspec­tors answered questions about the suitability of each method. Three experts (X) made the same assess­­ments, first individually just like the inspectors’, and then they agreed upon a consensus estimation. Head and upper arm position were registered by inclinometer, wrist movements with electro goniometer. The observers' assessments were com­pared with a “gold standard” that was created by the results of the technical measure­ments which re­placed the consensus esti­mates for the head and arm positions as well as wrist motions in the HARM, ART and HAL assessments. Results: The inspectors' assessment of HARM and ART showed in comparison with the res­pective “gold standard” some under­esti­ma­tion of risks. Conformity in the test-retest was 68 % at appraisal with HARM and 66 % with ART. Based on the inspectors' observations it was re­vealed that force and frequency were experienced as the most difficult to assess. On the other hand the indi­vi­dual assess­ments indicated that the work position of the hand and forearm showed the lar­gest deviation. Hand activity was both over and undervalued in comparison with tech­nical measurements, suggesting that it is difficult to simply assess hand activity by ob­ser­va­tion. Fur­thermore, the model for identifying repetitive work in AFS 1998:1 was perceived to be the most difficult to use for performing assess­ments, as it has few criteria and no support for the assessment of hand/arm and hand inten­si­ve move­ments. This under­lines that there is a need for other models as a supplement to the pro­visions. Conclusions: The results showed that the HARM and ART are relatively similar in content and struc­ture and provided relatively similar results. HARM is more detailed than ART as it takes into account the vibration exposure as a single factor and shows more consideration to the duration of exposure. The HARM-method provides support for the assessment; it is easy to use, it needs pen and paper only and is in that sense readily available, it is fast and takes into account the whole of the assessment of biomechanical exposure of the upper limbs. ART is very similar to HARM; HAL is more limited and can be used as a rapid screening of hand load.
Sammanfattning Inledning: Hand Arm RiskbedömningsMetod (HARM) är ett verktyg för bedömning av be­last­ning på hand och arm vid manuellt arbete. Metoden är framtagen i Nederländerna, i första hand till arbets­gi­va­re, metoden används också som ett stöd för arbetsmiljöinspektörer. Syftet med den här studien var att utvärdera HARM-metodens tillförlitlighet och dess lämp­lig­het som hjälpmedel för arbetsmiljö­inspek­törer vid riskbedömning av belastning på hand, arm och axel vid ma­nuellt arbete. Metod: Tio observatörer tillika arbetsmiljöinspektörer genomförde bedömningar av fem video­inspe­la­de arbets­moment.  Bedömningar gjorda med HARM jämfördes med bedöm­ningar med Assessment of Repetitive Tasks (ART) och Hand Activity Level (HAL) samt modellen för bedömning av ensidigt upprepat arbete i Arbetsmiljöverkets föreskrifter om belastningsergonomi, AFS 1998:1. HAL bygger på ett gränsvärde för handaktivitet. Metoden kombinerar bedömning av handens aktivitet med upplevd ansträng­ning i hand och underarm. Bedömningarna gjordes två gånger med två veckors mellanrum. I anslutning till varje bedömning besvarades frågor om respektive metods användbarhet. Tre experter (X) gjorde först enskilt mot­sva­rande bedömningar som observatörerna och enades därefter i en kon­sen­sus­be­döm­ning. Huvudets- och över­armarnas position registrerades med inklinometer, hand­leds­rö­rel­ser med elektro­gonio­me­ter. En ”gyllene standard” som observatörernas mätningar kunde jämföras med, skapades genom att resultaten av de tekniska mätningarna ersatte konsensusbedömningen för huvud- och armposition samt handledsrörelserna för HARM, ART och HAL. Resultat: Observatörernas bedömningar med HARM och ART visade i jämförelse med respektive gyllene standard på en viss undervärdering av risker. Överensstämmelsen vid test-retest av arbets­momenten var 68 % vid bedömning med HARM och 66 % med ART. Av observatörernas synpunkter framkom att kraft­ och frekvens upplevdes svårast att bedöma. Av de enskilda bedömningarna framkom dock att det var arbets­ställning i hand och underarm som visade den största avvikelsen. Handaktivitet både över- och undervärderades i jämförelse med tekniska mätningar, vilket pekar på att det är svårt att enbart genom ob­ser­va­tion bedöma handaktivitet. Vidare framgick att AFS upplevdes vara svårast att an­vän­da som underlag till en belastnings­ergono­misk riskbedömning, då den har få kriterier och saknar bedömnings­stöd för hand/arm och hand­in­tensiva rörelser. Detta understryker att det kan behövas ett komplement till AFS. Slutsatser: Resultaten visade att HARM och ART är relativt lika till innehåll och struktur och gav förhållandevis likvärdiga resultat. HARM är mer nyanserad än ART då den dels tar hänsyn till vibrationsexponering som en enskild faktor och dels justerar för exponeringstid. HARM-metoden ger stöd vid bedömning, är snabb och lätt att använda, endast papper och penna krävs och den tar hänsyn till hel­heten vid be­döm­ning av nack- och arm belastning. ART är mycket lik HARM. HAL är mer begränsad och kan användas som en snabb screeningmetod för handbelastning.

L’analyse 3D du mouvement humain repose généralement sur un ensemble d’hypothèses permettant de modéliser et d’approcher la complexité du corps humain. Le but de ce travail de thèse est de s’affranchir des hypothèses les plus classiques (liaisons simples et parfaites de type rotule ou pivot) dans les calculs de cinématique et de dynamique inverse allant jusqu'à l'estimation des forces musculo-tendineuses. La première partie de la thèse traite de la cinématique articulaire du genou à l’aide de modèles cinématiques « géométriques » représentant les structures anatomiques par des éléments simples (sphère, plan, barre). Ces modèles apparaissent sous la forme de contraintes lors des calculs de cinématique (effectués notamment par optimisation multi-segmentaire). Le travail réalisé a consisté à introduire des ligaments déformables par l’utilisation de méthodes de pénalités pour la gestion de cescontraintes. Il a été montré que ces méthodes, utilisées avec un modèle géométrique générique, permettaient une amélioration de l’estimation de la cinématique du genou in-vivo basée sur des marqueurs cutanés (par rapport aux autres méthodes classiques) en introduisant des couplages articulaires physiologiques. La flexibilité des méthodes permet également d’envisager lapersonnalisation des modèles. La seconde partie se penche sur la dynamique du membre inférieur en étudiant l’influence des actionspassives des structures péri-articulaires durant la marche. Le travail a consisté en une étude locale et une étude globale de ces actions. L’étude locale a montré que l’influence des moments passifs ligamentaires reste limitée sur les forces musculo-tendineuses et les forces de contact articulaire. L’étude globale a montré que les moments passifs de l’ensemble des structures péri-articulaires ontune contribution substantielle aux moments moteurs durant la marche et que les modèles de moments passifs ligamentaires disponibles dans la littérature ne sont pas fiables. L’ensemble de ces développements cherche, à terme, à permettre une approche multi-échelle de la modélisation du membre inférieur. Dans cette optique, la modélisation articulaire proposée (avec desliaisons qui ne sont plus ni simples ni parfaites) permet un couplage plus adapté entre les différentes modélisations (de type multi-corps rigides articulés et éléments finis)
The main objective of this work is to overcome the most classical hypotheses used in kinematics (lower pair mechanical joints) and inverse dynamics computation (joints without resistance) including the estimation of muscular forces. Kinematics is addressed in the first part of the thesis by using “geometric” kinematic models consisting in simple elements (sphere, plane, shaft) modeling the anatomical structures. These models correspond to constraints in the kinematic computation (especially in multi-body optimization). The work consisted in introducing deformable ligaments by using a penalty-based method. It has beenshowed that this method used with a generic geometric model improved the estimation of the knee kinematics from the skin markers, when compared to more classical methods, and introduce physiological couplings between the degrees of freedom. Model personalization is also considered thanks to the flexibility of the method. The influence of the passive structure actions during gait is studied in the second part of the thesis. The work consisted in a local and a global study of those actions. The local study showed that the influence on the joint contact and musculo-tendon forces of the ligament passive moments is limited. The global study showed that the passive moments of the whole peri-articular structures contribute to the motor moments during gait and that the passive ligament moments available in the literature are not appropriate. The long term objective of those studies is to develop a multi-scale approach of the lower limb modeling. The proposed articular modeling (with more complex joints) allows a better interaction between the different scales of modeling (rigid multi-body vs. finite elements)

O ambiente aquático é um recurso bastante utilizado na prática de atividade física, reabiltação e lazer. No entanto, apesar de seu amplo uso, pouco se sabe sobre a demanda mecânica a que nosso corpo está sujeito durante a atividade física neste ambiente. O conhecimento das cargas sobre o corpo durante exercícios em água poderá permitir uma melhor compreensão das adaptações realizadas pelo ser humano para se movimentar neste ambiente e, ainda, auxiliar na prescrição correta de atividades físicas. O objetivo deste trabalho foi, portanto, estimar as forças e torques articulares sobre o tornozelo, joelho e quadril de adultos jovens, saudáveis, durante o andar em ambiente terrestre e aquático (água rasa). Para tanto, conduzimos um experimento no qual 10 indivíduos caminharam com velocidade auto-selecionada nos dois ambientes. Durante o andar medimos as componentes da força de reação do solo, usando uma plataforma de força, e filmamos os movimentos, com auxílio de um de sistema de aquisição de imagens. As forças e torques internos foram determinadas através da técnica da dinâmica inversa e de estimativas das forças de arrasto e respectivos torques, realizadas a partir da teoria das faixas (\"strip theory\"). Os resultados referentes à cinemática articular e descritiva e às forças de reação do solo foram, no geral, semelhantes aos resultados apresentados em estudos anteriores, indicando que não há mudanças na coordenação dos movimentos articulares nem re- organização temporal da passada durante o andar em água. Entretanto, foi possível perceber mudanças nos sentidos dos torques articulares durante o ciclo para o joelho e o quadril, sugerindo que, para manter a mesma coordenação articular sob a ação do empuxo e do arrasto, é necessário promover mudanças nos padrões dos torques internos nestas articulações. Com relação à articulação do tornozelo, os resultados mostram que há diminuição nos torques articulares necessários para gerar a flexão plantar durante o apoio. A estimativa das forças de arrasto se mostrou adequada para descrever a situação experimental, o que indica que os valores apresentados neste estudo são adequados para descrever a carga mecânica no aparelho locomotor durante o andar em piscina com água rasa.
The aquatic environment is a resource often used for the practice of physical activity, rehabilitation, and leisure. However, despite its extensive use, little is known about the mechanical demand that our body is subjected during physical activity in this environment. The knowledge of the load on the human body during water exercise will give us a greater understanding of the adaptations of the human being in water and assist the health professional to the correct prescription for physical activities. The goal of this work was, therefore, to estimate the internal joint forces and moments on the ankle, knee, and hip joints of young healthy adults during walking in the terrestrial and aquatic (shallow water) environments. For that, we conducted an experiment in which 10 subjects walked with self-selected speed in both environments. During the experiment, we measured the components of ground reaction forces, with a force plate, and recorded the subject\'s movements with a video analysis system. To find the forces and moments we used the inverse dynamics procedure and the calculation of drag forces and moments were based on the strip theory. The results concerning the joints and descriptive kinematics and the ground reaction forces were, in general, similar to the results presented in previous studies, indicating that there aren\'t changes in the coordination of joint movements or a re-organization of the stride during walking in water. Meanwhile, we were able to see changes in the directions of joint moments during the gait cycle for the knee and hip joints, suggesting that to keep the same joint coordination under the action of drag and buoyancy, it is necessary to promote changes in the patterns of internal moments in these joints. As for the ankle, the results showed that there is a decrease in joint moments necessary to generate the plantar flexion during the support phase. The estimation of the drag forces was adequate to describe the experimental situation, which suggests that the values presented here can describe correctly the mechanical load on the locomotor system during walking in shallow water.

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The movements adopted during computer activities and mobile devices contribute to musculoskeletal disorders. However, there is no consensus about safe range of motion and the effect of weight bearing to reduce overload. The objective of the first study was to evaluate the bilateral muscle activity of descending trapezius and anterior deltoid in different shoulder flexion postures in conditions with and without forearm support in the seated position. The hypothesis was that the forearm support reduce muscle overload compared to the no supported condition, and the reduction this overload would be higher for the greater shoulder flexion angles. Twentythree healthy university students aged between 18 and 31 years were evaluated. The sample size was determined a priori. The electrical activity of the upper trapezius and deltoid muscles were collected bilaterally. The weight bearing was assessed by load cells. A physical therapist positioned the shoulder of the participants at flexion angles of 0º, 15º, 30º, 45º, 60º in conditions with and without forearm support, in randomized order. The results showed that the forearm support reduced muscle activity in different shoulder flexion angles. The forearm support was more important than the shoulder posture to determine muscle overload. However, in this first study a computer task was not evaluated. Besides the forearm support, the modification of the workstation can lead to change in biomechanical exposure and it was not investigated. Another important risk factor is the stress, which can also contribute to neck/shoulder disorders. Thus, the purpose of the second study was to evaluate the effect of the work surface height, weight bearing and the difficulty of the task in the head, upper back and upper arms postures and the electrical activity of the descending portion of the trapezius and anterior deltoid during simulated mouse activity in university students. The study hypothesis was that the high table combined with the high difficulty activity level would result in greater biomechanical overload, i.e. at higher angles of head flexion, upper trunk and shoulders, increased electrical activity of the descending portion of the trapezius muscle and anterior deltoid. Furthermore, it was expected that the weight bearing on the table would reduce muscle activation. Fifteen healthy university students aged between 18 and 31 years were evaluated. The sample size was not defined a priori. The head and upper back flexion angles and the upper arms elevation were evaluated by inclinometers. Muscle activity was collected bilaterally and normalized by the maximal voluntary isometric contraction (MVIC). The weight bearing was evaluated by load cells and included as a covariate for muscle activation. In the simulated task, participants simulated mouse activity with the table at the elbow height (EH) and above the elbow height (AEH) in low (LD) and high difficulty levels (HD). Each condition was evaluated during five minutes in a randomized order. The results indicated that the table in the EH provided greater postural overload of the head and less overload to the shoulders and trapezius muscle. The HD level increased the head and upper back flexion angles. Thus, the head posture seems to be influenced by the table height and task difficulty; the upper back posture is related to the difficulty of the activity and the upper arms posture and trapezius activation were only influenced by table height. Therefore, this study revealed the effect of ergonomic and psychosocial risk factors on muscle activation and posture. The results highlighted the importance of these factors for understanding the risk associated with computer use.
Os movimentos adotados durante atividades em terminais de vídeo e dispositivos móveis contribuem para os distúrbios musculoesqueléticos. Porém, não há um consenso em relação às amplitudes seguras e o efeito da descarga de peso para redução da sobrecarga. Assim, o objetivo do primeiro estudo foi avaliar a atividade muscular bilateral dos músculos trapézio descendente e deltóide anterior em diferentes posturas de flexão do ombro em condições com e sem o apoio de antebraço na postura sentada. A hipótese do estudo foi que o apoio do antebraço sobre a mesa reduziria a sobrecarga muscular em relação à situação sem uso do apoio, sendo que a redução desta sobrecarga seria maior quanto maior fosse o ângulo de flexão do ombro. Foram avaliadas 23 estudantes universitárias sadias com idade entre 18 e 31 anos. O tamanho amostral foi determinado a priori. A atividade elétrica dos músculos trapézio superior e deltóide foram coletadas bilateralmente. A descarga de peso foi avaliada por células de cargas dispostas sob a mesa. Um fisioterapeuta posicionou os ombros das participantes em flexão de 0º, 15º, 30º, 45º, 60º em condições com e sem apoio do antebraço, em ordem aleatorizada. Os resultados mostraram que o apoio de antebraço reduziu a atividade muscular nos diferentes ângulos de flexão do ombro. O apoio de antebraço foi mais importante do que a postura do ombro para determinar a sobrecarga muscular. Porém, neste primeiro estudo não foi avaliada uma condição dinâmica com o uso do computador. Além do apoio de antebraço, a modificação da estação de trabalho pode levar a mudança na exposição biomecânica e não foi investigada. Outro fator de risco importante é o estresse, que também pode contribuir para distúrbios na extremidade superior. Neste sentido, o objetivo do segundo estudo foi avaliar o efeito da altura da superfície de trabalho, da descarga de peso e da dificuldade da tarefa na postura da cabeça, tronco superior e ombros e na atividade elétrica da porção descendente do músculo trapézio e deltóide anterior durante atividade simulada de mouse em estudantes universitárias. A hipótese do estudo foi que a mesa alta combinada com o alto nível de dificuldade da atividade resultaria em maior sobrecarga biomecânica, ou seja, em maiores ângulos de flexão da cabeça, tronco superior e ombros, aumento da atividade elétrica da porção descendente do músculo trapézio e deltóide anterior. Além disso, esperava-se que a descarga de peso sobre a mesa reduzisse a ativação muscular. Foram avaliadas 15 estudantes universitárias sadias com idade entre 18 e 31 anos. O tamanho amostral não foi definido a priori. A atividade elétrica dos músculos trapézio superior e deltóide foram coletadas bilateralmente. Foram avaliados os movimentos dos ombros e cervical por meio de inclinometria. A descarga de peso foi avaliada por células de cargas dispostas sob a mesa. Os participantes realizaram uma atividade simulada com mouse em níveis de dificuldade baixo e alto, com a mesa na altura do cotovelo (AC) e acima da altura do cotovelo (ACC), em ordem aleatorizada. Os resultados indicaram que a mesa na AC proporcionou maior sobrecarga postural da cabeça e menor sobrecarga para os ombros e trapézio. O alto nível de dificuldade aumentou o ângulo de flexão da cabeça e tronco superior. Desta forma, a postura da cabeça parece estar permeada pela altura da mesa e dificuldade da atividade, a postura do tronco superior está relacionada com a dificuldade da atividade, já a postura dos ombros e a ativação do trapézio foram influenciadas apenas pela altura da mesa. Portanto, a presente dissertação revelou o efeito dos fatores ergonômicos e psicossociais sobre a ativação muscular e postura, sendo que a avaliação desses fatores é importante para o entendimento dos riscos envolvidos no uso do computador.

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The aim of this work was to investigate the influence of body posture during reaching movements in four healthy, four-month-old infants. Experimental conditions consisted of presenting two toys alternately, at the infant s midline and shoulder levels and midway between the infant s shoulder and wrist. After the reaching, the toy was taken away and given back again for a period of two minutes (for each toy) or until the infant reached for it a total of ten times. This procedure was repeated at the supine posture (0º), a reclined posture (45º) and a sitting posture (70º). We randomized this order these positions. The results were recorded on video and analyzed using the Dvideow system for the purpose of checking the kinematics of the angle of the shoulder (flexion/extension and abduction/aduction) and elbow flexion/extension). Also, we analyzed the rectitude index (the distance traveled by the hand during a reaching movement divided by the distance between the starting and the end points), time (in seconds) in each of the three positions, as well as the frequency of reaching unimanually and bimanually. The statistical method used for the rectitude index was t-Student test and for the frequency of reaching was the analysis of variance (ANOVA). From the results showed that there were differences between the frequency of reaching unimanually and bimanually (p-value=0,0341) in sitting posture. The frequency of reaching was more in sitting posture than in supine posture. In relation to the rectitude index, the test showed a significant difference between the supine and reclined postures (p-value=0,001) and the supine and sitting postures (p-value=0,001). The infants spent the same time reaching in the tree postures. When analyzing the angles, only two babies used the same movement pattern for the three positions. We concluded that, the age of 4 months, reaching does not follow a stable pattern, which can be modified by the position of the infant. Each infant has its own intrinsic dynamics and reacts in different ways to the environmental restrictions imposed by different body positions.
O presente estudo teve como objetivo investigar a influência da postura corporal na execução do movimento de alcance em quatro lactentes a termo, saudáveis, com idade de 4 meses de vida. A condição experimental consistia na apresentação de dois brinquedos, alternadamente, na altura dos ombros dos lactentes. Após o alcance, o brinquedo era retirado e apresentado novamente, durante um período de dois minutos para cada brinquedo ou até que o lactente realizasse 10 alcances. Este procedimento foi repetido nas posturas supina (0º), reclinada (45º) e sentada (70º), sendo a ordem escolhida de forma aleatória. As avaliações foram filmadas e analisadas pelo sistema Dvideow, com objetivo de verificar o comportamento das variáveis cinemáticas de ângulo de ombro (flexão/extensão e abdução/adução) e cotovelo (flexão/extensão), índice de retidão (distância percorrida pela mão durante o alcance dividido pela distância entre os pontos de início e fim) e tempo (segundos) em cada uma das três posições, além da freqüência de alcances unimanuais e bimanuais. O método estatístico empregado para o índice de retidão foi o teste t-Student e para a freqüência de alcances, a análise por variância (ANOVA). A partir dos resultados obtidos constatamos que houve diferença entre a freqüência de alcances unimanuais e bimanuais (p=0,0341) na postura sentada. A freqüência de alcances na postura sentada foi maior que na supina (p=0,038). Em relação ao índice de retidão, o teste indicou diferença significativa entre as posturas supina e reclinada (p=0,001) e entre supina e sentada (p=0,002). Os lactentes gastaram o mesmo tempo no alcance nas 3 posturas. Na análise dos ângulos, apenas dois lactentes usaram o mesmo padrão motor para as três posições. Baseando-se na abordagem dos sistemas dinâmicos, verificamos que o alcance ainda é um padrão instável de comportamento, o qual pode ser modificado pela posição do lactente. Cada lactente possui uma dinâmica intrínseca e responde de maneiras diferentes à restrição do ambiente imposta por meio das diferentes posições do corpo.

La capacité à percevoir des courants dans un fluide s'est développée chez de nombreuses espèces animales, dans des contextes écologiques très variés qui couvrent aussi bien les interactions proies-prédateurs, la sélection sexuelle ou l'orientation dans un environnement. Parmi ces espèces animales, les grillons détectent les courants d'air générés notamment lors de l'attaque de leurs prédateurs à l'aide de deux organes appelés "cerques", situés à l'arrière de leur abdomen et recouverts de poils mécano-sensoriels. Ces senseurs sont considérés comme les détecteurs les plus sensibles du monde animal. Il leur suffit de capter l'énergie d'un dixième d'un photon pour déclencher un potentiel d'action au niveau du neurone sensoriel. Ce manuscrit présente à la fois le développement des outils de mesures sans contact adaptés à ces questions d'écologie sensorielle ainsi que les méthodes numériques simulant les processus physiques à l'oeuvre. L'étude du fonctionnement des senseurs a nécessité l'adaptation des méthodes de mesures non intrusives de très grande précision tel que la Vélocimétrie par Imagerie de Particules (PIV). La couche limite oscillante dans laquelle évoluent les poils a été visualisée et a servi à déterminer la réponse de poils modélisés par des systèmes oscillatoires du second ordre. Le couplage visqueux entre poils a été lui aussi caractérisé en adaptant la PIV à des mesures à très petites échelles sur des poils biomimétiques micro-electro-mécanique (MEMS). Les mesures des perturbations générées lors des attaques d'araignées, principales prédatrices des grillons, nous ont aidé à valider des modélisations numériques, réalisées à l'aide des techniques de dynamique des fluides computationnelles (CFD) par résolution des équations de Navier Stokes via la méthode des éléments finis (FEM). La mise au point et l'utilisation de techniques de métrologie optique en dynamique des fluides semi-visqueux et l'analyse des données nous permettent de revisiter la sensibilité extrême du système sensoriel du grillon et de placer ces mesures dans un contexte plus large, d'écologie sensorielle. En particulier, nous montrons que ces soies sont placées en groupe compact et exercent entre elles un fort couplage aérodynamique visqueux, qui réduit fortement leur sensibilité "de groupe". Ce fort couplage interroge l'intérêt d'avoir des récepteurs aussi performants individuellement, s'ils perdent leur sensibilité lorsqu'ils fonctionnent en réseau. Finalement, les réactions des poils à des mouvements de fluides générés par un piston mimant les attaques réelles d'araignées ont pu être déterminées à l'aide d'une caméra rapide, puis simulées et validées après avoir développé un modèle mécanique du poil répondant à des stimuli transitoires
Flow sensing is used by a vast number of animals in various ecological contexts, from preypredator interactions to mate selection, and orientation to flow itself. Among these animals, crickets use hundreds of filiform hairs on two cerci as an early warning system to detect remote potential predators. Over the years, the cricket hairs have been described as the most sensitive sensor in the animal kingdom. The energy necessary for the emission of an action potential by its sensory neuron was estimated to be a tenth of the energy of a photon. This PhD thesis aims to describe recent technological advances in the measurement and model of flows around biological and artificial flow sensors in the context of organismal sensory ecology. The study and understanding of the performance of sensory systems requires a high spatial precision of non-intrusive measurement methods. Thus, non-contacting measurement methods such as and Particle Image Velocimetry (PIV), originally developed by aerodynamics and fluid mechanics engineers, have been used to measure flows of biological relevance. The viscous oscillatory boundary layer surrounding filiform hairs has been visualized and used as input to model the mechanical response of these hairs, described as second order mechanical systems. The viscous hydrodynamic coupling occurring within hair canopy was also characterized using PIV measurements on biomimetic micro-electro-mechanical systems (MEMS) hairs, mimicking biological ones. Using PIV, we have also measured the air flow upstream of hunting spiders. We prove that this flow is highly conspicuous aerodynamically, due to substantial air displacement detectable up to several centimeters in front of the running predator. This disturbance of upstream air flows were also assessed by computational fluid dynamics (CFD) with the finite elements method (FEM). The development of non-intrusive measurement and CFD methods and their application to the analysis of the biological flow involved in cricket sensory ecology allowed us to revisit the extreme sensitivity of cricket filiform hairs. We predicted strong hydrodynamic coupling within natural hair canopies and we addressed why hairs are packed together at such high densities, particularly given the exquisite sensitivity of a single hair. We also proposed a new model of hair deflection during the arrival of a predator, by taking into account both the initial and long-term aspects of the flow pattern produced by a lunging predator. We conclude that the length heterogeneity of the hair canopy mirrors the flow complexity of an entire attack, from launch to grasp

Canada’s workforce, as well as many other countries, is continuing to age as the baby boomer generation (those born between 1946 and 1964) ages and are remaining in the workforce longer. The number of older workers is estimated to double within the next 10 years (Perry 2010). With increased age, there are a number of factors that could influence worker performance and risk of injury. For example, aging is associated with decreased strength and cardiovascular fitness. However, it is unknown whether a worker’s estimates of how much they can safely lift (based on an approach called psychophysics, which is often used in the design of manual materials handling tasks) is lower for older compared to younger workers. The primary goal of this thesis was to test the hypothesis that psychophysical estimates of maximum acceptable forces would be lower for older workers than younger workers during selected lifting tasks. The secondary goal was to measure a host of variables to provide insights into what factors (e.g. kinematic, strength, cardiovascular) might be influencing potential age-related differences. The experimental testing protocol used a psychophysical approach to identify the maximum acceptable mass of an object during several lifting tasks. Participants comprised a total of 24 female workers (12 older (50+ years old) and 12 younger (20-30 years old)). The primary outcome of interest was the maximum acceptable weight of lift (MAWL) for an 8 hour work day that would allow each participant to ‘work as hard as they can without straining themselves, or becoming unusually tired, weakened, overheated, or out of breath’ (Snook and Ciriello 1991). The participants completed four lifting tasks: floor-to-knuckle height (1 lift/9s and 1 lift/2 min) and knuckle-to-shoulder height (1 lift/2 min and 1 lift/8 hr) by adding or removing lead shot to a lifting box. Tasks were 30 minute in duration; participants could adjust the load mass at any time during the trial. The dependent variables collected were the MAWL (the load mass at the end of the trial), maximum sagittal plane joint angles of the shoulder, hip and knee, overall and body part specific ratings of perceived exertion, and heart rate. Older workers selected MAWL values that were significantly lower (by approximately 24%) than their younger counterparts. These age-related differences were more prevalent for tasks which were constrained by strength (i.e. low frequency) compared to those with large cardiovascular requirements (i.e. high frequency). The only significant difference in the sagittal plane joint flexion angle was for the right hip during the 1 lift/2 min from floor-to-knuckle height lifting task, characterized by 34.4 degree decrease hip angle (more flexed) for the older workers. There were also no significant age-related differences in overall ratings of perceived exertion. The only body part-specific rating of perceived exertion with a significant age-related difference was for the knees, with the younger workers reporting the tasks more taxing on this joint than the older workers. Although there were no age-related differences in absolute heart rate values, the older workers were at a significantly higher percentage of their maximum heart rate. The results of this work suggest there is value in continued research probing whether current ergonomic and work design guidelines need to be updated to accommodate the aging working population. According to the results presented in this study, the current approaches often employed during the design of manual materials handling tasks (i.e. incorporating the loads that 75% of females could perform based on the Snook and Ciriello tables (1991) may not be sufficiently protective for older female workers in the workplace.

Title: Analysis of the immediate effect of kinesiotaping on the upper limbs when landing into a press-up position when doing gymnastic aerobics Objectives: The aim of this diploma thesis is to find out if the use of the tape on the upper limbs changes the acceleration associated with the reaction inertial force of the arm, the angle in the elbow joint and wrist when landing into the press-up position, as well as subjective evaluation of probands. The hypothesis for the practical part is that the angles in the joints mentioned and the magnitude of the force with the applied tap change, which would result in better stabilization of the upper limbs in this element, as well as positive evaluation of the probands. Methods: The theoretical part deals with kinesiological-biomechanical description of upper limbs and the characteristics of gymnastic aerobics. Moreover, biomechanical analysis and kinesiotaping are described. The practical part is devoted to the measurement of landings into the press-up position  first without tape and then with tape. The tape is described in detail. The XSens MVN was used to record motion. Results: The results showed that kinesiotape had no effect on the angle of the elbow and wrist joints or shoulder joints when landing into the press-up position. However, a positive...

碩士
國立成功大學
醫學工程學系
81
The mechanics of the lower limbs were analyzed in 14 young, adult healthy subjects when rising from a seated position by motion analysis system and force plateforms. Limbs mechanics were described in terms of angles and moments at the hip, knee and ankle joints while rising from three seat heights corres- ponding to 80, 100 and 110% of subject's knee joint height, and under condition of ankle constrained. An analysis of variance with repeated measures showed the following results: 1) wether the ankle joints were constrained or not, the peak angle value of three joints decreased with increasing chair height. 2) there was significant difference in peak angle value of left ankle , both knee and left hip joints, compared between snkle conditions and compared among chair height (P<0.05). 3) there was signifi- cant difference in peak moment of left knee joint, when rising from the chair with 80 and 110% of subject's knee joint height (P<0.05). 4) the difference between two peak moments of left hip joint when rising from three kinds of chair and compared between ankle conditions had significant finding (P<0.05). The study implies that the height of chair and range of ankle joint have influences on the lower limbs when rising from the chair, so we should keep the angle of ankle joint as complete as possible and we should suggest the patient with limited range of ankle joints sitting on the higher chair to prevent the heavier load on the limbs.

Title: Motion analysis of lower extermity during squatting Aims: The aim of the thesis is to compare the squat without and with external load in a group of people who work under professional guidance and have experience with this movement, contrary to the people of the common population. Another objective will be the compasion this movement among men and women of the common population. In the theoretical part, the main objective is to describe the basic characteristic of the squat, describe the kinesiological and biomechanical findings and the risks of this movement on the locomotive apparatus. The experimental part will focus on the observation of the determined kinematic parameters of squats and their comparison in the mentioned set of persons. The results of the work should clarify the possible side effects of the squat. Methods: Kinematic analysis will be performed using Qualisys instrumentation. Infrared cameras accurately record and further perform a motion action through passive or active reflection markers. Data from the device will be processed in Microsoft Office Excel software and further evaluated statistically. Results: The results show that there are significant variations in the performance of the movement among groups of men actively engaged in squats under professional guidance and...

In this paper we use multivariate statistical techniques to gain insights into how adaptive gait involving obstacle crossing is regulated in lower-limb amputees compared to able-bodied controls, with the aim of identifying underlying characteristics that differ between the two groups and consequently highlighting gait deficits in the amputees. Eight unilateral trans-tibial amputees and twelve able-bodied controls completed adaptive gait trials involving negotiating various height obstacles; with amputees leading with their prosthetic limb. Spatiotemporal variables that are regularly used to quantify how gait is adapted when crossing obstacles were determined and subsequently analysed using multivariate statistical techniques. There were fundamental differences in the adaptive gait between the two groups. Compared to controls, amputees had a reduced approach velocity, reduced foot placement distance before and after the obstacle and reduced foot clearance over it, and reduced lead-limb knee flexion during the step following crossing. Logistic regression analysis highlighted the variables that best distinguished between the gait of the two groups and multiple regression analysis (with approach velocity as a controlling factor) helped identify what gait adaptations were driving the differences seen in these variables. Getting closer to the obstacle before crossing it appeared to be a strategy to ensure the heel of the lead-limb foot passed over the obstacle prior to the foot being lowered to the ground. Despite adopting such a heel clearance strategy, the lead-foot was positioned closer to the obstacle following crossing, which was likely a result of a desire to attain a limb/foot angle and orientation at instant of landing that minimised loads on the residuum (as evidenced by the reduced lead-limb knee flexion during the step following crossing). These changes in foot placement meant the foot was in a different part of swing at point of crossing and this explains why foot clearance was considerably reduced in amputees. The results highlight that trans-tibial amputees use quite different gait adaptations to cross obstacles compared with controls (at least when leading with their prosthetic limb), indicating they are governed by different constraints; seemingly related to how they land on/load their prosthesis after crossing the obstacle.
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Passive prosthetic devices are set up to provide optimal function at customary walking speed and thus may function less effectively at other speeds. This partly explains why joint kinetic adaptations become more apparent in lower-limb amputees when walking at speeds other than customary. The present study determined whether a trans-tibial prosthesis incorporating a dynamic-response foot that was attached to the shank via an articulating hydraulic device (hyA-F) lessened speed-related adaptations in joint kinetics compared to when the foot was attached via a rigid, non-articulating attachment (rigF). Eight active unilateral trans-tibial amputees completed walking trials at their customary walking speed, and at speeds they deemed to be slow-comfortable and fast-comfortable whilst using each type of foot attachment. Moments and powers at the distal end of the prosthetic shank and at the intact joints of both limbs were compared between attachment conditions. There was no change in the amount of intact-limb ankle work across speed or attachment conditions. As speed level increased there was an increase on both limbs in the amount of hip and knee joint work done, and increases on the prosthetic side were greater when using the hyA-F. However, because all walking speed levels were higher when using the hyA-F, the intact-limb ankle and combined joints work per meter travelled were significantly lower; particularly so at the customary speed level. This was the case despite the hyA-F dissipating more energy during stance. In addition, the amount of eccentric work done per meter travelled became increased at the residual knee when using the hyA-F, with increases again greatest at customary speed. Findings indicate that a trans-tibial prosthesis incorporating a dynamic-response foot reduced speed-related changes in compensatory intact-limb joint kinetics when the foot was attached via an articulating hydraulic device compared to rigid attachment. As differences between attachment conditions were greatest at customary speed, findings indicate a hydraulic ankle-foot device is most effectual at the speed it is set-up for.

Over one million amputees are living in the United States with major lower limb loss (Ziegler-Graham et al. 2008). Lower limb amputation leads to the functional loss of the ankle plantar flexor muscles, which are important contributors to body support, forward propulsion, and leg swing initiation during walking (Neptune et al. 2001; Liu et al. 2006). Effective prosthetic component design is essential for successful rehabilitation of amputees to return to an active lifestyle by partially replacing the functional role of the ankle muscles. The series of experimental and computer simulation studies presented in this research showed that design characteristics of energy storage and return prosthetic ankles, specifically the elastic stiffness, significantly influence residual and intact leg ground reaction forces, knee joint moments, and muscle activity, thus affecting muscle output. These findings highlight the importance of proper prosthetic foot stiffness prescription for amputees to assure effective rehabilitation outcomes. The research also showed that the ankle muscles serve to stabilize the body during turning the center of mass. When amputees turn while supported by their prosthetic components, they rely more on gravity to redirect the center of mass than active muscle generation. This mechanism increases the risks of falling and identifies a need for prosthetic components and rehabilitation focused on increasing amputee stability during turning. A proper understanding of the effects of prosthetic components on amputee walking mechanics is critical to decreasing complications and risks that are prevalent among lower-limb amputees. The presented research is an important step towards reaching this goal.
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Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Eletrónica Médica)
In order to actively aid or restore legged locomotion to individuals suffering from muscular impairments, weakness or neurologic injury, rehabilitation is recommended as a more appropriate way to achieve the ultimate goal of a continuous ambulatory monitoring. Also, the assistance with wearable robots (WRs) during daily living activities provides a more intensive and purposeful targeted therapeutic training, and also reduces the treatment cost and the number of health care personnel. Thus, it is crucial the development of locomotion strategies that recognize in real-time the locomotion mode of human-robot interaction in overground daily living activities. Thus, this thesis intends to develop two locomotion strategies which will be integrated in high level control of exoskeleton H2 (Exo-H2), the WR developed under the scope of BioMot project. The first locomotion strategy proposed and validated addresses online detection of events and gait phases uniquely through information from embedded sensors. This knowledge will allow determining in real-time the biomechanical parameters of assisted walking, and consequently to assess the progress of rehabilitation process by means of WR. The solution validation in different locomotion conditions (assisted walking by WR, walking of humanoid robot and walking of healthy subject) shows up that the proposed solution led to a robust and general tool for gait detection, which is also capable to detect more events and gait phases comparatively to the works presented in literature. Locomotion mode recognition is the second locomotion strategy developed in this thesis, which allows the recognition of different locomotion modes. Based on an exhaustive state of the art survey, a more robust and accurate procedure that leads to a more robust and accurate tool was delineated. According to the results achieved for offline scenario it was verified that the performance of the locomotion strategy increases by using different types of biomechanical parameters, which should be previously selected by means of multivariate statistic methods. Both binary and multiclass classification were addressed through support vector machine (SVM). The implementation of these methods led to a powerful and accurate tool of offline recognition of locomotion modes. Additionally, a strategy for online recognition was proposed. Further work will consist on the application of these locomotion strategies in real-time environment of gait rehabilitation.
De forma a apoiar ou a restaurar a locomoção de indivíduos que apresentam fraqueza muscular ou doenças neurológicas, a reabilitação é recomendada como a forma mais apropriada para alcançar uma monitorização ambulatória contínua. Além disso, a assistência com robots ambulatório (RA) durante as atividades diárias promove um treino terapêutico mais intensivo e direcional, assim como também reduz os custos de tratamento e o número de profissionais de saúde. Como tal, é crucial o desenvolvimento de estratégias que reconheçam, em tempo real, o modo de locomoção da interação sujeito-robot durante as atividades quotidianas. Assim, esta tese visa desenvolver duas estratégias de locomoção, as quais serão integradas no controlo de alto nível do Exo-H2, que corresponde ao RA desenvolvido no âmbito do projeto BioMot. A primeira estratégia de locomoção proposta e validada consiste na deteção online dos eventos e fases da marcha, usando exclusivamente a informação fornecida pelos sensores embebidos. Este conhecimento permitirá a determinação em tempo real dos parâmetros biomecânicos da marcha assistida, e por conseguinte permitirá avaliar o progresso da reabilitação. A validação da solução proposta em diferentes contextos de locomoção (marcha assistida por RA, marcha de um robot humanoide e a marcha de um sujeito saudável) revelou que esta constitui uma ferramenta robusta e geral para a deteção da marcha, sendo capaz de detetar mais eventos e fases da marcha comparativamente aos estudos apresentados na literatura. O reconhecimento do modo de locomoção é a segunda estratégia desenvolvida nesta tese, a qual permite o reconhecimento de diferentes modos de locomoção. Com base no exaustivo levantamento do estado da arte, foi delineado um procedimento robusto, que conduziu a uma ferramenta mais robusta e precisa. De acordo com os resultados alcançados para o cenário offline verificou- se que o desempenho desta estratégia de locomoção aumenta com a utilização de diferentes tipos de parâmetros biomecânicos, os quais devem ser previamente selecionados por meio de métodos estatísticos. Tanto a classificação binária, como a classificação de multi-classes, foram implementadas através do support vector machine (SVM). A implementação destes métodos conduziu a uma ferramenta precisa de reconhecimento dos modos de locomoção em offline. Além disso, também foi proposta a estratégia para o reconhecimento em tempo real. Como trabalho futuro propõe-se a aplicação destas estratégias de locomoção no ambiente em tempo real de reabilitação da marcha.