Les flux d'air intérieurs, d'origine naturelle ou mécanique, participent de manière significative au transport de particules et aux transferts thermiques au sein des bâtiments. Que ce soit pour des raisons de santé et sécurité au travail, de confort thermique ou encore d'économie d'énergie, il est crucial de pouvoir les étudier sur place pour mieux les maîtriser. L'objectif de cette thèse aura été de développer une méthode permettant de mesurer sur site, la vitesse de flux d'air intérieurs sur de grands domaines d'observation (supérieurs au mètre carré). Pour cela, nous nous sommes tournés vers les techniques basées images qui consistent à suivre le mouvement de traceurs passifs introduits dans l'air pour en déduire une estimation de sa vitesse. Ce type de méthode est déjà largement utilisé en laboratoire de recherche pour étudier les écoulements dans des contextes bien maîtrisés. Cependant, le passage à la mesure sur le terrain et à l'observation grand champ nécessitent quelques adaptations. Ces adaptations concernent notamment le choix de nouveaux traceurs, l'éclairage ainsi que la méthode d'estimation de mouvement à partir de séquences d'images. Dans un premier temps, nous avons développé un algorithme d'estimation de mouvement permettant l'estimation de la vitesse aux grandes échelles à partir d'images de particules et d'images de scalaire. Nous avons ensuite éprouvé en soufflerie, sur des écoulements de couche de mélange et de sillage de cylindre, une méthode de mesure basée image grand champ n'utilisant qu'une seule caméra, un éclairage LED, des traceurs de type bulles ou fumée ainsi que l'algorithme évoqué plus haut. Nous avons confronté la mesure obtenue à une mesure réalisée par anémométrie à fil chaud. Les résultats de cette campagne de mesure ont montré la capacité de la méthode à mesurer les principales caractéristiques des écoulements considérés. Enfin, nous avons appliqué la méthode développée à une mesure sur site du flux d'aspiration d'une sorbonne de laboratoire en conditions réelles de fonctionnement. Cette mesure a permis de mettre en évidence des zones de forte turbulence et de recirculation, sources de fuites potentielles. / Whether for reasons of health and safety at work, thermal comfort or energy saving, it is crucial to study them on site to better control them. The objective of this thesis was to develop a method to measure on site, the speed of indoor air flows over large areas of observation (greater than a square meter). To this end, we turned to image-based techniques that consist in following the movement of passive tracers introduced into the air to infer an estimate of its velocity. This kind of method is already widely used in research laboratories to study flows in well-controlled contexts. However, the transition to on-site measurement and wide field of interest requires some adaptations. These adaptations concern, in particular, the choice of new tracers, the lighting system as well as the motion estimation method from image sequences. First, we developed a motion estimation algorithm that allows the estimation of large-scale velocities from particle images and scalar images. We then tested in our wind tunnel, on mixing layer and cylinder wake flows, a large-scale image-based measurement method using only one camera, a LED lighting system, bubbles or smoke tracers as well as the algorithm mentioned above. We compared the obtained measurement with a measurement carried out by hot-wire anemometry. The results of this measurement campaign showed the ability of the method to measure the main characteristics of the considered flows. Finally, we applied the developed method to an on-site measurement of the suction flow of a laboratory fume hood under real operating conditions. This measure has made it possible to highlight areas of high turbulence and recirculation, causing potential leakages.

Die vorliegende Arbeit beschäftigt sich mit der Analyse des Volleyballangriffsschlages von der Position vier unter Wettkampfbedingungen. Der Angriffsschlag von dieser Position ist oft die spielentscheidende Einflußgröße, da die meisten Punkte von dieser Position aus erzielt werden. Es handelt sich um einen komplexen Bewegungsablauf und es gibt eine Vielzahl an Untersuchungen, die sich mit der bewegungsanalytischen Untersuchung des Angriffsschlages befassen. Eine Herausforderung der generellen Problemstellung liegt darin, den Bewegungsablauf adäquat zu parametrisieren. Verschiedene Studien beschäftigten sich beispielsweise ausschließllich mit der Armbewegung während der Schlagphase oder mit der Beinbewegung während der Absprungphase. Die Dissertation ist darauf ausgerichtet eine breite Datenbasis für die Analyse von Volleyballangriffsschlägen zu schaffen. Der innovative Charakter der Arbeit liegt dabei in drei wesentlichen Punkten: - Definition leistungsrelevanter Parameter - Analyse von Angriffsschlägen unter Wettkampfbedingungen . große Stichprobe Insbesondere die Analyse von Angriffsschlägen während internationaler Wettkämpfe stellt dabei eine Herausforderung dar und hebt diese Arbeit von anderen Studien in der Literatur ab. Einerseits bietet dieser Ansatz die Möglichkeit "reale" Bewegungsabläufe im Spiel zu betrachten, andererseits verringert sich dadurch die Standardisierbarkeit der Umgebungsbedingungen. Die methodische Innovation liegt darin, zu untersuchen, welche Bewegungsabläufe unter echten Wettkampfbedingungen ausgeführt werden. Die wissenschaftliche Innovation liegt in der Identifikation und Definition leistungsrelevanter Parameter, die den Bewegungsablauf quantifizieren können. Damit kann ein Einblick gewonnen werden, was unter Spielbedingungen einen erfolgreichen Angriffsschlag ausmacht.

It has been shown that the interface between the prosthetic socket and residual limb (S-RL) interface is an important factor in determining acceptance and outcomes of upper limb prostheses. [1] Among the most common complaint from amputees is that the prosthesis is uncomfortable due to developing skin irritation which is usually attributed to poor fit (Nielson 1990). In order to understand why skin irritations can and do occur it is imperative to examine the biomechanical properties of the S-RL interface. A primary reason behind the development of skin irritation is instability of the socket upon the residuum. Alley (2009) asserts that excess slip, axial rotation, and translation are the facets of instability that cause skin irritations due to friction and shear. Measuring the motion at the S-RL interface is not commonly done and therefore there is still no valid and reliable method to quantify the motion clinically. A licensed prosthesis fabricated a transhumeral residual limb model to fit within a typical, harness suspended transhumeral prosthesis. A custom testing apparatus was built to hold the residual limb model and prosthesis for testing. Eight infrared markers were placed on the prosthesis and residual limb model: Two each respectively on the "wrist", elbow axis, socket, and on the residual limb model. The model consists of 3 rigid segments, the forearm, socket, and residual limb. Pearson r correlations were done to see how strongly correlated the motion analysis calculated values were to the accepted values. All results were significant with a r < = .95 and p < .05.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20259号 / 医博第4218号 / 新制||医||1020(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邉 大, 教授 林 康紀, 教授 髙橋 良輔 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Femoroacetabular impingement syndrome (FAI) is a hip impairment, which is according to recent studies significant contributor to hip osteoarthritis. Current research is dedicated to evaluate movement patterns of hip, pelvis and spine in patients with FAI using a motion analysis capture system. Biomechanics and kinesiology relations between spino-pelvic complex and lower limb joints led us to choose the topic of this thesis. The goal of this study was to define the movements of ankle and foot in patients with FAI syndrome and to compare with asymptomatic control group. To measure the parameters during gait we used Qualisys motion capture system and then the data were processed in Qualisys Track Manager 2020.03. We assessed the movements of ankle, rearfoot and the progression foot angle during the stance phase of gait cycle. Moreover, we measured the step length, gait speed and passive range of motion of the hip in both exploratory groups. In total we examinated 30 subjects, 15 with FAI syndrome and 15 asymptomatic volunteers with physiologic hip condition. We demonstrated three significant between group changes in average ankle range of motion in sagittal plane, foot progression angle and passive range of motion of the hip.

In the long distance running community there is currently controversy as a result of the release of Advanced Footwear Technology (AFT) type of shoes. The AFT shoes with performance enhancing mechanical properties are currently used with great success. All of the current world records in long distance running have been set by athletes wearing the novel type of shoes. The new type of shoes have been shown to reduce energetic cost of running but the exact mechanisms of the reduced energetic cost are still unclear. In the research community several hypotheses of mechanisms and performance enhancing features exist. In this thesis the focus was on investigating the performance enhancing feature, energy return and the effect it has on the biomechanical variables, ground reaction force, joint moments and joint power.  For this thesis five male subelite to elite runners were recruited. The participants ran over two force platforms with a controlled running velocity while motion data was recorded with a marker based motion analysis system. The curves from the contact of the foot with the force platform were analysed with the motion analysis software, Visual 3D and the SPM1D statistical package in Matlab.  The results suggest that energy return properties of AFT shoes do affect lower extremity loading. Significant differences in the biomechanical variables GRF, ankle moment and ankle power were seen between high energy return shoes and low energy return shoes. In addition the number of significantly different intervals show a tendency of a pattern, where shoes share the largest amount of significantly different intervals with shoes that are furthest away on the energy return list. However, shoe #4 did not behave according to the energy return ranking. This means that a sole dependency on energy return characteristics was not found.    The knowledge gained from this thesis does not reduce the controversy surrounding the shoes. It does however establish a base for further research in the area of AFT. From that base, further research could create a solid scientific understanding of the shoes, which can be used to justify regulation changes. Regulations with a solid scientific backing would reduce the controversy. / Inom långdistanslöpning finns det för närvarande en kontrovers till följd av lanseringen av skor av typen Advanced Footwear Technology. Advanced Footwear Technology-skor med prestandaförbättrande mekaniska egenskaper används för närvarande med stor framgång. Alla nuvarande världsrekord i långdistanslöpning har satts av idrottare som bär den nya typen av skor. Det har visat sig att den nya typen av skor minskar den energetiska kostnaden för löpning, men de exakta mekanismerna för den minskade energetiska kostnaden är fortfarande oklara. Inom forskarvärlden finns flera hypoteser om mekanismer och prestationshöjande egenskaper. I den här uppsatsen låg fokus på att undersöka den prestationshöjande egenskapen, energiåtergivning, och vilken effekt den har på de biomekaniska variablerna markreaktionskraft, ledmoment och ledeffekt.  För denna uppsats rekryterades fem manliga subelit- till elitlöpare. Deltagarna sprang över två kraftplattformar med en kontrollerad löphastighet medan rörelsedata registrerades med ett markörbaserat rörelseanalyssystem. Kurvorna från fotens kontakt med kraftplattformen analyserades med rörelseanalys-programmet Visual 3D och statistikpaketet SPM1D i Matlab.  Resultaten tyder på att AFT-skor har egenskaper som ger energiåtergivning och som påverkar belastningen på nedre extremiteterna. Signifikanta skillnader i de biomekaniska variablerna GRF, fotledsmoment och fotledskraft sågs i resultaten. Dessutom visar antalet signifikant olika intervall en tendens till ett mönster, där skor delar det största antalet signifikant olika intervall med skor som ligger längst bort på listan över energiåtergivning. Sko #4 uppförde sig dock inte i enlighet med rangordningen för energiåtergivning. Detta innebär att man inte har funnit något beroende av egenskaperna för energiåtervändning.    Den kunskap som erhållits genom denna uppsats minskar inte kontroverserna kring skorna. Den skapar dock en grund för ytterligare forskning inom området Advanced Footwear Technology. Utifrån denna grund kan ytterligare forskning skapa en solid vetenskaplig förståelse för skorna, som kan användas för att motivera ändringar av regler. Ett regelverk med ett gediget vetenskapligt stöd skulle minska kontroverserna.

The objectives of this study were to 1) calculate participant-specific segment inertial parameters using dual energy X-ray absorptiometry (DXA) data (referred to as full DXA-driven parameters) and compare the pitching arm kinetic predictions using full DXA-driven inverse dynamics vs scaled, DXA mass-driven (using DXA masses but scaled centers of mass and radii of gyration), and DXA scaled inverse dynamics(ID) (using the full DXA-driven inertial parameters averaged across all participants), 2) examine associations between full DXA-driven kinetics and body mass index (BMI) and 3) examine associations between full DXA-driven kinetics and segment mass index (SMI). Eighteen 10- to 11- year-olds pitched 10 fastballs. DXA scans were conducted and examined to obtain 3D inertial parameters of the upper arm, forearm, and hand. Full DXA-driven and scaled inertial parameters were compared using paired t-tests. Pitching arm kinetic predictions calculated with the four methods (i.e. scaled ID, DXA mass-driven ID, full DXA-driven ID, and DXA scaled ID) were compared using a repeated measures ANOVA with Tukey post-hoc tests. The major results were that 1) full DXA-driven participant specific inertial parameters differed from scaled inertial parameters 2) kinetic predictions significantly varied by method and 3) full DXA-driven ID predictions for shoulder compression force and shoulder internal rotation torque were significantly associated with BMI and/or SMI.

Human motion capture technology is a powerful tool for advancing the understanding of human motion biomechanics (Andriacchi and Alexander, 2000). This is most readily accomplished by applying retroreflective markers to a participant’s skin and tracking the position of the markers during motion. Skin and adipose tissue move independently of the underlying bone during motion creating error known as soft tissue artifact (STA), the primary source of error in human motion capture (Leardini et al., 2005). (Solav et al., 2014) proposed and (Solav et al., 2015) expanded the triangular Cosserat point element (TCPE) method to reduce the effect of STA on derived kinematics through application of a marker cluster analyzed as a set of triangular Cosserat point elements. This method also provides metrics for three different modes of STA. Here the updated TCPE method (Solav et al., 2015) was compared to the established point cluster (PC) method of (Andriacchi et al., 1998) and the marker position error minimizing Procrustes solution (PS) method of (Söderkvist and Wedin, 1993) in two implant-based simulations, providing quantitative measures of error, and standard gait analysis, providing qualitative comparisons of each method’s determined kinematics. Both of these experiments allowed the TCPE method to generate observed STA parameters, informing the efficacy of the simulation. The TCPE method’s performance was similar to the PS method’s in the implant simulations and in standard gait. The PC method’s results seemed to be affected by numerical instability: simulation trial errors were larger and standard gait results were only similar to the other methods’ in general terms. While the PS and TCPE results were comparable, the TCPE method’s physiological basis provided the added benefit of non-rigid behavior quantization through its STA parameters. In this study, these parameters were on the same order of v magnitude between the standard gait experiments and the simulations, suggesting that implant simulations could be valuable substitutes when invasive methods are not available.

Biomechanics research investigating gait and balance of ultimate frisbee players is an unexplored topic. Ultimate requires a wide range of motions that could improve balance and is also a sport prone to frequent injury. This study explores the impact of playing ultimate on gait parameters associated with balance and knee angles associated with joint injury. Gait trials were conducted on 8 ultimate players and 8 control participants between the ages of 18 and 23 to obtain total double support time, stance phase time, single support time, load response time, abduction-adduction (AA) angles, internal-external (IE) rotation angles, and flexion angles of the dominant leg’s knee. Knee angles were obtained through the application of a Triangular Cosserat Point Element (TCPE) analysis for Soft-Tissue Artifact (STA) correction of knee kinematics. The gait parameters and knee angles were compared between ultimate players and control group participants using two-sample t tests. The results indicated that (1) playing ultimate may be used to improve balance, and (2) playing ultimate may reduce the range of IE rotation angles.

Non-contact injuries can occur when athletes use poor or inconsistent mechanics during typical sport-related movements like landing from a jump. Anterior cruciate ligament (ACL) injuries are especially devastating, and certain populations like female athletes and athletes with a previous ACL reconstruction (ACLR) are at greater risk of suffering an ACL injury, with altered biomechanical strategies being one proposed reason. Asymmetric landings where one limb experiences greater landing force can decrease joint stability and place the overloaded limb at greater risk for ACL injury. Additionally, a stiff landing, characterized by increased ground reaction force (GRF), extended joints at initial ground contact, and decreased joint flexion throughout the landing, has been proposed to increase ACL injury risk. While load distribution between limbs is a common landing assessment to determine injury risk, it is unclear what role limb stiffness plays in the likelihood of experiencing an ACL injury. Limb stiffness is simply the deformation of the limb in response to the downward force applied to the lower limb during ground contact, which can be approximated using GRF. Limb stiffness has been commonly used to assess performance in running, hopping, and jumping, however, its relationship with injury risk during landings is relatively unexplored. Past research has revealed that the ACL experiences peak strain prior to initial ground contact when the knee is at or near full extension. Additionally, expert video analyses have determined that ACL injuries most likely occur within 50 milliseconds of ground contact. It is possible that limb stiffness and limb stiffness asymmetry can be used during the early impact phase of landings to reveal ACLR- and sex-specific landing mechanics differences when the ACL appears to be most vulnerable. Moreover, game-like, sport-specific landing tasks with a greater horizontal component that load the ACL and those that divert attention away from landing strategies may uncover differences that do not appear in standard, controlled laboratory tasks. The overall goal of this project was to use limb stiffness, limb stiffness asymmetry, and related measures to analyze the early landing phase mechanics of groups at greater risk for ACL injury during game-like, sport-specific landings. First, in an ACLR cohort, greater knee power and knee work asymmetries were found when compared to healthy recreational athletes, supporting previous literature that found that athletes with an ACLR land unevenly by offloading their surgical limb. However, limb stiffness asymmetry was not different between groups, implying that the groups may have modulated limb stiffness differently between limbs. Second, minimal sex-by-task interactions were determined for landings that varied by horizontal approach prior to initial ground contact. Significant differences were found for most measures across tasks overall, however, male and female athletes displayed similar landing mechanics, indicating that expected sex-specific differences may not exist during the immediate landing phase when ACL injuries are thought to occur. Last a landing task that mimicked a ball in mid-air and diverted attention away from landing mechanics produced a sex-by-task interaction for peak impact force but no other measure. When comparing each sex-task pairing, a trend for greater peak impact force by female athletes during the distracted landing (p=0.098) was found which may indicate that future tasks with additional external focuses or another game-like component will reveal anticipated sex-specific differences. Increased time between limbs for initial ground contact for female athletes also revealed that a time-synchronized assessment of between-limb coordination may be beneficial for future research. / Doctor of Philosophy / Non-contact injuries can occur when athletes use poor or inconsistent mechanics during typical sport-related movements like landing from a jump. Anterior cruciate ligament (ACL) injuries are especially tough, and certain populations like female athletes and athletes with a previous ACL reconstruction surgery (ACLR) are at greater risk of suffering an ACL injury, with different movement techniques being one proposed reason. Uneven landings where one limb has greater landing forces can decrease joint posture and place the overloaded limb at greater risk for ACL injury. Additionally, a stiff landing, defined by larger ground reaction force (GRF), extended joints at initial ground contact, and decreased joint flexion throughout the landing, is thought to increase ACL injury risk. While landing force distribution between limbs is a common way of evaluating landings to determine injury risk, it is unclear what role limb stiffness plays in the likelihood of experiencing an ACL injury. Limb stiffness is simply the deformation of the limb in response to the downward force applied on the lower limb during ground contact, which can be estimated using GRF. Limb stiffness has been commonly used to assess performance in running, hopping, and jumping, however, its relationship with injury risk during landings is pretty limited. Past research has revealed that the ACL experiences maximum stretch prior to initial ground contact when the knee is or is almost completely straight. Additionally, expert video investigations have determined that ACL injuries most likely occur within 50 milliseconds of ground contact. It is possible that limb stiffness and limb stiffness asymmetry can be used during the early impact phase of landings to reveal sex- and ACLR-specific landing mechanics differences when the ACL appears to be most in danger. Additionally, game-like, sport-specific landing tasks with a greater horizontal element that load the ACL and those that redirect attention away from landing strategies may show differences that do not appear in basic laboratory tasks. The overall goal of this project was to use limb stiffness, limb stiffness asymmetry, and related measures to examine the early landing phase techniques of groups at greater risk for ACL injury during game-like, sport-specific landings. First, in a group of athletes with a previous ACLR, greater knee storage differences between limbs were found when compared to healthy recreational athletes, supporting previous research studies that found that athletes with an ACLR land unevenly by offloading their surgical limb. However, limb stiffness asymmetry was not different between groups, implying that the groups may have regulated limb stiffness differently between limbs. Second, only a couple measures were significantly affected by the combined effect of sex and task during landings that were different due to their horizontal element. Significant differences were found for most measures across tasks overall, however, male and female athletes had similar landing techniques, showing that the expected differences between sexes may not happen very early in the landing phase when ACL injuries are thought to happen. Last, a landing task that imitated a ball in mid-air and redirected attention away from landing mechanics produced a larger sex-specific difference for peak impact force compared to a basic landing task. When comparing each sex-task pairing, a trend for greater peak impact force by female athletes during the distracted landing (p=0.098) was found which may show that future tasks with additional distractions or another game-like element will reveal expected differences between sexes. Increased time between limbs for initial ground contact for female athletes also revealed that looking at the coordination of both limbs on the same timescale may be useful for future research.