京都大学 / 新制・課程博士 / 博士(人間健康科学) / 甲第24095号 / 人健博第102号 / 新制||人健||7(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 市橋 則明, 教授 稲富 宏之, 教授 松田 秀一 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM

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Floor vibration serviceability is a primary design consideration for steel framed floors. Designers in North America typically use the AISC Design Guide 11 methods to check this limit state, but its methods are difficult to apply to atypical floor framing. Finite element analysis is a logical choice for predicting vibration response to walking, but simplified designer-friendly procedures are not available. Three relatively simple, experimentally verified methods of predicting low frequency floor vibration due to walking are presented in this dissertation. The methods are based on finite element analysis of the floor system, are applicable to a wide range of situations, and are intended to be no more complicated than is justified by the current ability to predict modal properties. The first method is to predict the acceleration response using response history analysis with individual footstep forces as the loading function. The second method also uses response history analysis to predict the acceleration waveform, but with a Fourier series representation of the load. The third method is a simplified frequency domain method in which the predicted accelerance frequency response function is used to predict the steady-state response to walking which is reduced to account for incomplete resonant build-up. A two year experimental program including three laboratory specimens, a four bay full-scale mockup, and two steel-framed building floors, was completed at Virginia Tech. These floor systems represent a wide cross-section of the steel framed floor systems used in North America. Modal tests were performed using an electrodynamic shaker and experimental modal analysis techniques were used to estimate the modal properties: natural frequencies, mode shapes, and damping ratios. Responses to walking excitation were measured several times in each tested bay for individuals walking at subharmonics of natural frequencies. During each test, the walker crossed the middle of the bay using a metronome to help maintain the intended cadence. The test with maximum response represents the maximum peak acceleration that can be reasonably expected to occur due to a single walker. The proposed methods were used, with measured damping ratios and walker weights, to predict the modal properties and responses to walking for comparison with measured values. The methods were found to be reasonably accurate, contain significant data dispersion, and be on the conservative side. The results of these comparisons were used to develop design recommendations, including reduction factors to account for the conservatism. The design methods were used to predict the modal properties and responses to walking in a "blind" manner using only information that would be available to a designer. Comparisons of measurements and predictions were used to determine the accuracy of the proposed prediction methods, which were found to be sufficiently accurate for design usage. / Ph. D.

O objetivo deste estudo é analisar a influência de dois modelos distintos de calçado esportivo falsificado (indoor e jogging) sobre características dinâmicas e eletromiográficas da locomoção humana. Oito voluntários participaram do estudo, dos quais cinco realizaram os testes com os calçados do modelo indoor e três realizaram os testes com os calçados do modelo jogging, testando a versão original e falsificada de seus respectivos modelos de calçado durante a marcha e a corrida. Foram coletados dados referentes à força de reação do solo (FRS) (esteira com plataformas de força - Sistema GAITWAY) e à atividade eletromiográfica (EMG 1000 Sistema Lynx). Os resultados mostram o aumento de Fy1, Imp50 e Imp75 durante a marcha, e o aumento de Fy1 e GC1 durante a corrida com o uso do calçado falsificado indoor, caracterizando situações de maior sobrecarga e influência negativa deste calçado. Ao usar-se o calçado falsificado indoor, observou-se também alteração no envoltório linear dos músculos tibial anterior, vasto lateral, bíceps femoral e reto femoral durante a marcha, aumento do valor RMS do m. vasto lateral e m. reto femoral durante a marcha e aumento do valor RMS do m. gastrocnêmio lateral durante a corrida, provavelmente em resposta ao aumento da carga externa. Por outro lado, o uso do calçado falsificado jogging não induziu a nenhuma alteração nos parâmetros de FRS e atividade muscular analisados, em nenhum dos movimentos estudados. Conclui-se que diferentes modelos de calçado falsificado influenciam de forma distinta a sobrecarga imposta ao aparelho locomotor e o comportamento muscular durante a locomoção / The purpose of this study is to analyze the influence of two different types of falsified running shoes (indoor and jogging) upon dynamic and electromyographic characteristics during human locomotion. Eight subjects had participated of this study: five of them tested the original and falsified indoor running shoe, while three of them tested the original and falsified jogging running shoe. All subjects tested their shoes during walking and running. Data from ground reaction force (GRF) were obtained by a treadmill with force plates (GAITWAY System), while electromyographic data was obtained by EMG-1000 (LYNX System). The results show an increase in Fy1, Imp50 and Imp75 during walking and an increase in Fy1 and LR1 during running when wearing the falsified indoor running shoe, indicating a considerable increment in the mechanical load and a negative influence from this shoe. When wearing the falsified indoor running shoe, it is possible to observe alterations in the muscular activation pattern for the muscles Tibialis Anterior, Vastus Lateralis, Biceps Femoris and Rectus Femoris during walking; a higher RMS for m. Vastus Lateralis and m. Rectus Femoris during walking; and an increase in RMS for m. Gastrocnemius Lateralis during running. Probably, these alterations occurred in response to the higher external forces. On the other hand, the falsified jogging running shoe has not shown any alteration for GRF and muscular activation parameters. Its possible to conclude that different types of falsified running shoe can influence the mechanical load and the muscular behavior in different ways during locomotion

Les signaux multicanaux sont des signaux captés à travers plusieurs canaux ou capteurs, portant chacun un mélange de sources, une partie desquelles est connue alors que le reste des sources reste inconnu. Les méthodes à l’aide desquelles l’isolement ou la séparation des sources est accomplie sont connues par les méthodes de séparation de sources en général, et si le degré d’inconnu est large, par la séparation aveugle des sources (SAS). Cependant, la SAS appliquée aux signaux multicanaux est en fait plus facile de point de vue mathématique que l’application de la SAS sur des signaux monocanaux, ou un seul capteur existe et tous les signaux arrivent au même point pour enfin produire un mélange de sources inconnues. Tel est le domaine de cette thèse. Nous avons développé une nouvelle technique de SAS : une combinaison de plusieurs méthodes de séparation et d’optimisation, basée sur la factorisation non-négative des matrices (NMF). Cette méthode peut être utilisée dans de nombreux domaines comme l’analyse des sons et de la parole, les variations de la bourse, et les séismographes. Néanmoins, ici, les signaux de force de réaction de terre verticaux (VGRF) monocanaux d’un groupe d’athlètes coureurs d’ultra-marathon sont analysés et séparés pour l’extraction du peak passif du peak actif d’une nouvelle manière adaptée à la nature de ces signaux. Les signaux VGRF sont des signaux cyclo-stationnaires caractérisés par des double-peaks, chacun étant très rapide et parcimonieux, indiquant les phases de course de l’athlète. L’analyse des peaks est extrêmement importante pour déterminer et prédire la condition du coureur : problème physiologique, problème anatomique, fatigue etc. De plus, un grand nombre de chercheurs ont prouvé que l’impact du pied postérieur avec la terre d’une manière brutale, l’analyse de ce phénomène peut nous ramener à une prédiction de blessure interne. Ils essayent même d’adopter une technique de course - Non-Heel-strike Running (NHS) - par laquelle ils obligent les coureurs à courir sur le pied-antérieur seulement. Afin d'étudier ce phénomène, la séparation du peak d’impact du VGRF permet d'isoler la source portant les informations patho-physiologiques et le degré de fatigue. Nous avons introduit de nouvelles méthodes de prétraitement et de traitement des signaux VGRF pour remplacer le filtrage de bruit traditionnel utilisé partout, et qui peut parfois détruire les peaks d’impact qui sont nos sources à séparer, base sur le concept de soustraction spectrale pour le filtrage, utilisée avec les signaux de parole, après l’application d’un algorithme d’échantillonnage intelligent et adaptatif qui décompose les signaux en pas isolés. Une analyse des signaux VGRF en fonction du temps a été faite pour la détection et la quantification de la fatigue des coureurs durant les 24 heures de course. Cette analyse a été accomplie au domaine fréquentiel/spectral où nous avons détecté un décalage clair du contenu fréquentiel avec la progression de la course indiquant la progression de la fatigue. Nous avons défini les signaux cyclosparse au domaine temporel, puis traduit cette définition à son équivalent au domaine temps-fréquence utilisant la transformée Fourier a court-temps (STFT). Cette représentation a été décomposée à travers une nouvelle méthode que l’on a appelé Cyclosparse Non-negative Matrix Factorisation (Cyclosparse-NMF), basée sur l’optimisation de la minimisation de la divergence Kullback-Leibler (KL) avec pénalisation liée à la périodicité et la parcimonie des sources, ayant comme but final d’extraire les sources cyclosparse du mélange monocanal appliquée aux signaux VGRF monocanaux. La méthode a été testée sur des signaux analytiques afin de prouver l’efficacité de l’algorithme. Les résultats se sont avéré satisfaisants, et le peak impact a été séparé du mélange VGRF monocanal. / The purpose of the presented work is to develop a customized Single-channel Blind Source Separation technique that aims to separate cyclostationary and transient pulse-like patterns/sources from a linear instantaneous mixture of unknown sources. For that endeavor, synthetic signals of the mentioned characteristic were created to confirm the separation success, in addition to real life signals acquired throughout an experiment in which experienced athletes were asked to participate in a 24-hour ultra-marathon in a lab environment on an instrumented treadmill through which their VGRF, which carries a cyclosparse Impact Peak, is continuously recorded with very short discontinuities during which blood is drawn for in-run testing, short enough not to provide rest to the athletes. The synthetic and VGRF signals were then pre-processed, processed for Impact Pattern extraction via a customized Single-channel Blind Source Separation technique that we termed Cyclo-sparse Non-negative Matrix Factorization and analyzed for fatigue assessment. As a result, the Impact Patterns for all of the participating athletes were extracted at 10 different time intervals indicating the progression of the ultra-marathon for 24 hours, and further analysis and comparison of the resulting signals proved major significance in the field of fatigue assessment; the Impact Pattern power monotonically increased for 90% of the subjects by an average of 24.4 15% with the progression of the ultra-marathon during the 24-hour period. Upon computation of the Impact Pattern separation algorithm, fatigue progression showed to be manifested by an increase in reliance on heel-strike impact to push to the bodyweight as a compensation for the decrease in muscle power during propulsion at toe-off. This study among other presented work in the field of VGRF processing forms methods that could be implemented in wearable devices to assess and track runners’ gait as a part of sports performance analysis, rehabilitation phase tracking and classification of healthy vs. unhealthy gait.

O objetivo deste estudo é analisar a influência de dois modelos distintos de calçado esportivo falsificado (indoor e jogging) sobre características dinâmicas e eletromiográficas da locomoção humana. Oito voluntários participaram do estudo, dos quais cinco realizaram os testes com os calçados do modelo indoor e três realizaram os testes com os calçados do modelo jogging, testando a versão original e falsificada de seus respectivos modelos de calçado durante a marcha e a corrida. Foram coletados dados referentes à força de reação do solo (FRS) (esteira com plataformas de força - Sistema GAITWAY) e à atividade eletromiográfica (EMG 1000 Sistema Lynx). Os resultados mostram o aumento de Fy1, Imp50 e Imp75 durante a marcha, e o aumento de Fy1 e GC1 durante a corrida com o uso do calçado falsificado indoor, caracterizando situações de maior sobrecarga e influência negativa deste calçado. Ao usar-se o calçado falsificado indoor, observou-se também alteração no envoltório linear dos músculos tibial anterior, vasto lateral, bíceps femoral e reto femoral durante a marcha, aumento do valor RMS do m. vasto lateral e m. reto femoral durante a marcha e aumento do valor RMS do m. gastrocnêmio lateral durante a corrida, provavelmente em resposta ao aumento da carga externa. Por outro lado, o uso do calçado falsificado jogging não induziu a nenhuma alteração nos parâmetros de FRS e atividade muscular analisados, em nenhum dos movimentos estudados. Conclui-se que diferentes modelos de calçado falsificado influenciam de forma distinta a sobrecarga imposta ao aparelho locomotor e o comportamento muscular durante a locomoção / The purpose of this study is to analyze the influence of two different types of falsified running shoes (indoor and jogging) upon dynamic and electromyographic characteristics during human locomotion. Eight subjects had participated of this study: five of them tested the original and falsified indoor running shoe, while three of them tested the original and falsified jogging running shoe. All subjects tested their shoes during walking and running. Data from ground reaction force (GRF) were obtained by a treadmill with force plates (GAITWAY System), while electromyographic data was obtained by EMG-1000 (LYNX System). The results show an increase in Fy1, Imp50 and Imp75 during walking and an increase in Fy1 and LR1 during running when wearing the falsified indoor running shoe, indicating a considerable increment in the mechanical load and a negative influence from this shoe. When wearing the falsified indoor running shoe, it is possible to observe alterations in the muscular activation pattern for the muscles Tibialis Anterior, Vastus Lateralis, Biceps Femoris and Rectus Femoris during walking; a higher RMS for m. Vastus Lateralis and m. Rectus Femoris during walking; and an increase in RMS for m. Gastrocnemius Lateralis during running. Probably, these alterations occurred in response to the higher external forces. On the other hand, the falsified jogging running shoe has not shown any alteration for GRF and muscular activation parameters. Its possible to conclude that different types of falsified running shoe can influence the mechanical load and the muscular behavior in different ways during locomotion

Ground reaction force (GRF) data collected and synchronized with film data to determine peak GRF and calculate moments about ankle and knee during rope skipping. Two, five minute conditions were analyzed for 10 subjects. Condition 1 was set rate and style. Condition 2 was subjects' own rate and style. Means and standard deviations were reported for peak GRF, ankle and knee moments. One way ANOVAs reported no significant difference between conditions for variables measured. Efficiency and nature of well phased impacts during rope skipping may be determined by combination of GRF, similarities in magnitude and direction of joint moments, and sequencing of segmental movements. Technique and even distribution of force across articulations appear more important than magnitudes of force produced by given styles.

<p>  </p> <p>Falls mostly occur when people are walking. Investigations of control of gait stability have focused primarily on the single stance phase. My dissertation focused on the double support phase of gait because (1) responses to perturbations occur during the double support (2) the portion of the gait cycle spent in double support is increased with old age, and, more importantly, (3) since both feet can push off the ground simultaneously, there are more kinetic degrees of freedom (DoF) and therefore greater control authority over body motion during this phase. However, how these kinetic DoFs are coordinated during the double support phase is not fully understood. Thus, the goal of this dissertation was to identify the inter-leg coordination to stabilize whole-body motion and quantify how the inter-leg coordination is affected by intrinsic and extrinsic factors. Specifically, Study 1 focused on healthy aging (an intrinsic factor) and varying task demands (an extrinsic factor that changed while curb ascent versus curb descent). Study 2 investigated another extrinsic factor of future uncertain environmental demands (fixed versus uncertain foot targeting demand for the step after descending a curb). Using the uncontrolled manifold analysis, I identified ground reaction variable (GRV) synergies, i.e., synergistic covariations between the ground reaction forces and moments under the two feet that stabilize whole-body linear and angular motions. Furthermore, I found that GRV synergies were modulated by extrinsic factors: GRV synergies were sensitive to current fixed environmental demands (Study 1), whereas they were robust to future environmental demands on foot placement (Study 2). Lastly, I found that GRV synergies were not changed by the intrinsic factor of age, despite the physiological declines with aging (Study 1). The absence of an age effect on GRV synergies indicates that older adults have the preserved ability to exploit the control authority during the double support phase to maintain stability while negotiating a curb. The work extends the current body of literature on gait stability mechanisms and improves our understanding of changes in stability control as a function of different environmental demands.</p>

Context: Knee pain is a common symptom in knee pathology and is associated with alterations in quadriceps activation and movement patterns. Reducing pain through intervention may help reestablish neuromuscular function. The independent effects of knee pain are difficult to examine and unclear. Objective: To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on quadriceps activation and vertical ground reaction force (VGRF) during walking. Design: Crossover. Setting: Laboratory. Subjects: 15 in the TENS group (10M and 5F, 23.5 ± 2.8 yrs, 70.5 ± 12.5 kg, 178.1 ± 7.4 cm), and 15 in the sham group (10M and 5F, 22.5 ± 2.0 yrs, 72.1 ± 13.7 kg, 177.5 ± 9.3 cm). Interventions: Subjects underwent three experimental conditions (pain, sham, and control). Measurements were recorded across four time points (preinfusion, infusion, treatment, and posttreatment). Hypertonic or isotonic saline, respectively, was infused into the infrapatellar fat pad for 48 minutes (total 7.7 mL). The TENS group received a 20-minute treatment. A sham treatment was administered to the sham group. Main Outcome Measures: Perceived knee pain on a 10-cm visual analog scale, knee extension maximum voluntary isometric contraction (MVIC) normalized to body mass, knee extension central activation ratio (CAR), and VGRF. Results: Knee pain peaked at 4 cm during infusion and remained consistent across time in the sham group (F2,28 = 49.90, P < 0.0001), while knee pain gradually decreased to 1.5 cm following TENS treatment (F2,28 = 23.11, P < 0.0001). A group x condition x time interaction was detected for both the MVIC (F6,168 = 2.92, P < 0.01) and CAR (F6,168 = 3.03, P < 0.008) measurements. Post hoc analysis revealed that the infusion of hypertonic saline reduced knee extension MVIC by 29% in the TENS group, and by 26% in the sham group (P < 0.05). However, while the MVIC remained depressed by 26% following sham treatment, the MVIC was found to improve by 12% following TENS treatment (P < 0.05). Similarly, a 10% decrease in CAR was detected in both sham and TENS groups prior to treatment. This 10% deficit held, with a 9% deficit following sham treatment, while the deficit of CAR was improved by 4% following TENS treatment (P < 0.05). For the TENS group, infusion of hypertonic saline changed VGRF at initial loading, midstance, and push-off phase. VGRF was only different at initial loading and push-off phase following TENS treatment. For the sham group however, sham treatment did not restore VGRF, showing alterations in initial loading, midstance, and push-off phase (α = 0.05). Conclusions: Infusion of hypertonic saline increased perceived knee pain, reduced knee extension MVIC, reduced CAR, and altered VGRF over some of stance phase. TENS lessened the deficits in MVIC, CAR, and VGRF, suggesting decreased muscle inhibition and improved movement function.

Polypterus senegalus, an extant member of the ray-finned fishes, can both swim in water and walk overland. Both environments impose different locomotor requirements on Polypterus fins. In an aquatic environment, forward propulsion is largely generated through oscillations of the pectoral fins working in sync with each other. On land, the pectoral fins are engaged in a contralateral gait, and are involved in lifting the body off the ground while simultaneously balancing the body. Polypterus have been shown to undergo behavioural, anatomical, and physiological changes during both short- and long-term exposure to land. Differences in force environments and locomotor behaviour between aquatic and terrestrial environments are hypothesized to be the cause of these plastic changes observed in the musculoskeletal tissues of Polypterus. Despite these observable changes, it is unclear exactly how the pectoral fins are experiencing ground reaction forces (GRF) during terrestrial locomotion. By measuring and quantifying force production during walking in Polypterus, this thesis provides a first look at the relationship between GRFs produced and experienced during walking and the pectoral fins of the amphibious fish, Polypterus. The kinematics of the pectoral fins and fore body were analyzed during terrestrial locomotion, and strategic points across both pectoral fins and body were digitized. Kinematics were compared with GRFs in the thrust (X), stabilizing (Y) and lifting (Z) planes to understand how impact forces travel through the fin tissues. Further analysis, using inverse dynamics, is required to determine how these impact forces travel through the musculature of the pectoral fins, perhaps providing potential hypotheses as to the effects of GRFs and their role in not only how terrestrial locomotion affects the behavioural, anatomical, and physiological plasticity observed in Polypterus, but also the limbs of tetrapods during the evolutionary transition from aquatic to terrestrial environments.