Littérature scientifique sur le sujet « Video Kinematic Evaluation »
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Articles de revues sur le sujet "Video Kinematic Evaluation"
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Matsuzaki, Yukiko, Madison R. Heath, Julianne M. Khan, Elad Spitzer et Peter D. Fabricant. « Reliability of Two-Dimensional Video-Based Analysis in Adolescent Runners ». Orthopaedic Journal of Sports Medicine 9, no 7_suppl3 (1 juillet 2021) : 2325967121S0007. http://dx.doi.org/10.1177/2325967121s00072.
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Background: Running analysis is an essential component of evaluation of both injured runners and uninjured runners seeking advice on injury prevention. Reliability of two-dimensional (2D) video analysis has been reported in the adult running population. However, these findings may not apply to youth runners given their unique state during growth and development. The reliability of quantitative and qualitative video-based running gait analysis in the adolescent population is unknown. Purpose: The purpose of this study was to determine the intra-rater and inter-rater reliability of sagittal and frontal plane kinematics using 2D video analysis in healthy adolescent runners. Methods: High-definition videos were recorded of 10 healthy runners between 14-18 years old running on a treadmill at self-selected speed with markers attached to the thoracic spine, pelvis, and lower extremities. Kinematic variables in the sagittal and frontal planes were measured using Dartfish Motion Analysis Software™ (Fribourg, Switzerland) by three raters. Intra- and inter-rater reliability were calculated using Intraclass Correlation Coefficients (ICCs). Results: Of the 10 runners, 4 (40%) were male and the mean age was 16 ± 1.5 years. The intra-rater ICC for all kinematic variables ranged from 0.574 to 0.999 for the primary sports physical therapist, and 0.367 to 0.973 for the inexperienced research assistant. The inter-rater ICC for all raters ranged from -0.01 to 0.941. Eleven kinematic variables showed substantial agreement and 4 showed almost perfect agreement. Step width and foot progression showed fair and poor agreement, respectively. Conclusion: The results of this study demonstrate that a 2D video-based running analysis can be reliably performed in an adolescent population on all kinematic variables except for step width and foot progression. Inexperienced raters can be properly trained in the video analysis of running kinematics using Dartfish Software in order to consistently assess the same runner. [Table: see text][Table: see text]
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Geonea, Ionut Daniel, Nicolae Dumitru et Alexandru Margine. « Motion Evaluation Of A Wheelchair Prototype For Disabled People ». ACTA Universitatis Cibiniensis 67, no 1 (1 septembre 2015) : 44–50. http://dx.doi.org/10.1515/aucts-2015-0062.
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Abstract In this paper is presented the design solution and experimental prototype of a wheelchair for disabled people. Design solution proposed to be implemented uses two reduction gears motors and a mechanical transmission with chains. It’s developed a motion controller based on a PWM technology, which allows the user to control the wheelchair motion. The wheelchair has the ability of forward – backward motion and steering. The design solution is developed in Solid Works, and it’s implemented to a wheelchair prototype model. Wheelchair design and motion makes him suitable especially for indoor use. It is made a study of the wheelchair kinematics, first using a kinematic simulation in Adams. Are presented the wheelchair motion trajectory and kinematics parameters. The experimental prototype is tested with a motion analysis system based on ultra high speed video cameras recording. The obtained results from simulation and experimentally tests, demonstrate the efficiency of wheelchair proposed solution.
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Zahradka, Nicole, Khushboo Verma, Ahad Behboodi, Barry Bodt, Henry Wright et Samuel C. K. Lee. « An Evaluation of Three Kinematic Methods for Gait Event Detection Compared to the Kinetic-Based ‘Gold Standard’ ». Sensors 20, no 18 (15 septembre 2020) : 5272. http://dx.doi.org/10.3390/s20185272.
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Video- and sensor-based gait analysis systems are rapidly emerging for use in ‘real world’ scenarios outside of typical instrumented motion analysis laboratories. Unlike laboratory systems, such systems do not use kinetic data from force plates, rather, gait events such as initial contact (IC) and terminal contact (TC) are estimated from video and sensor signals. There are, however, detection errors inherent in kinematic gait event detection methods (GEDM) and comparative study between classic laboratory and video/sensor-based systems is warranted. For this study, three kinematic methods: coordinate based treadmill algorithm (CBTA), shank angular velocity (SK), and foot velocity algorithm (FVA) were compared to ‘gold standard’ force plate methods (GS) for determining IC and TC in adults (n = 6), typically developing children (n = 5) and children with cerebral palsy (n = 6). The root mean square error (RMSE) values for CBTA, SK, and FVA were 27.22, 47.33, and 78.41 ms, respectively. On average, GED was detected earlier in CBTA and SK (CBTA: −9.54 ± 0.66 ms, SK: −33.41 ± 0.86 ms) and delayed in FVA (21.00 ± 1.96 ms). The statistical model demonstrated insensitivity to variations in group, side, and individuals. Out of three kinematic GEDMs, SK GEDM can best be used for sensor-based gait event detection.
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Hannah, Iain, Andy Harland, Dan Price, Heiko Schlarb et Tim Lucas. « Evaluation of a Kinematically-Driven Finite Element Footstrike Model ». Journal of Applied Biomechanics 32, no 3 (juin 2016) : 301–5. http://dx.doi.org/10.1123/jab.2015-0002.
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A dynamic finite element model of a shod running footstrike was developed and driven with 6 degree of freedom foot segment kinematics determined from a motion capture running trial. Quadratic tetrahedral elements were used to mesh the footwear components with material models determined from appropriate mechanical tests. Model outputs were compared with experimental high-speed video (HSV) footage, vertical ground reaction force (GRF), and center of pressure (COP) excursion to determine whether such an approach is appropriate for the development of athletic footwear. Although unquantified, good visual agreement to the HSV footage was observed but significant discrepancies were found between the model and experimental GRF and COP readings (9% and 61% of model readings outside of the mean experimental reading ± 2 standard deviations, respectively). Model output was also found to be highly sensitive to input kinematics with a 120% increase in maximum GRF observed when translating the force platform 2 mm vertically. While representing an alternative approach to existing dynamic finite element footstrike models, loading highly representative of an experimental trial was not found to be achievable when employing exclusively kinematic boundary conditions. This significantly limits the usefulness of employing such an approach in the footwear development process.
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Vladimir, Potop. « Improving Sports Technique of Jaeger Salto on Uneven Bars Based on Biomechanical Indicators ». New Trends and Issues Proceedings on Advances in Pure and Applied Sciences, no 8 (22 décembre 2017) : 83–91. http://dx.doi.org/10.18844/gjapas.v0i8.2820.
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This paper aims at improvement of key sports technique elements using kinematic and dynamic indicators of Jaeger salto on uneven bars during the training stages. The methods used in this research include analysis of the literature; evaluation of techniques of gymnastics exercises using algorithmic structural–systemic analysis of movement; video-computerised methods using ‘Pinnacle Studio’, ‘Kinovea’ and ‘Physics ToolKit’; movement postural orientation and evaluation of sports technique with complex coordination of movement structure; linear-branched programming of learning and improvement; and the ‘KyPlot’ program. Correlative analysis of the indicators of Jaeger salto and performances by 12–15-year-old gymnasts highlighted the connection between the kinematic and dynamic characteristics of sports techniques and the scores in competitions. Video-computerised methods, the method of movement postural orientation and algorithmic analysis of sports technique of Jaeger salto on uneven bars contributed to effective development of long-term learning programmes, improvement of technical execution and achievement of better performances. Keywords: Gymnastics, uneven bars, biomechanics, key elements, long-term programmes of learning, performance.
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Theoret, C. L., S. M. Barber, R. D. Curie et Hilary M. Clayton. « Effects of Carpal Synovectomy on Stride Kinematics of Trotting Horses ». Veterinary and Comparative Orthopaedics and Traumatology 11, no 02 (1998) : 80–84. http://dx.doi.org/10.1055/s-0038-1632615.
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SummaryA group of eight horses was used to study the effects of synovectomy of one antebrachiocarpal joint on stride kinematics of the trot. Two months after the operation, four of the horses started a progressive exercise program lasting two months. A standardised lameness evaluation and videographic gait analysis were performed on three occasions: two days before the operation, two days after the operation and four months after the operation when the exercise programme had been completed. There were no significant differences in clinical lameness score, amplitude of poll motion, maximal metacarpophalangeal angle, maximal carpal angle, or minimal carpal angle between the synovectomized limb and the unoperated limb on any of the three evaluation days. It is concluded that carpal synovectomy did not cause lameness in the immediate post-operative period, and that strenuous exercise can safely be commenced after a two month recovery period, unless underlying cartilaginous lesions dictate otherwise.Gait analysis was performed qualitatively using a standard clinical examination and quantitatively using videographic analysis to measure kinematic variables that have previously been associated with lameness. Following synovectomy of one antebrachiocarpal joint no signs of lameness were observed on clinical examination and there were no asymmetrics in the kinematic variables. A strenuous exercise program, which commenced 2 months after surgery and lasted for 2 months, was completed without the development of clinical or video-graphic signs of lameness.
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Litvinenko, Y. V., Tomasz Niznikowski et V. N. Boloban. « Evaluation of the kinematic structure of indicators key elements of sports equipment exercise by postural orientation movements ». Physical education of students 18, no 6 (28 décembre 2014) : 29–36. http://dx.doi.org/10.15561/20755279.2014.0606.
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Purpose : Examine the kinematic structure of indicators key elements of sports equipment exercise (difficult to coordinate). The method of postural orientation movements. Material : The study involved acrobats jumpers on the path of high qualification (n = 7). The method used video - computer recording the movements of the athlete. Results : Identified nodal elements of sports equipment double back somersault tuck. Exercise performed after rondat and double back flip and stretch after rondat - flick (coup ago). In the preparatory phase of motor actions acrobatic exercises isolated and studied central element of sports equipment - starting posture of the body; in the phase of the main motor action - animation poses of the body; in the final phase - the final body posture (stable landing). Conclusions : The method of video - computer registration allowed to perform a biomechanical analysis and evaluation of key elements of sports equipment double back somersault tuck and a double back flip and stretch. Also gain new knowledge about the mechanism of the phase structure of movements when performing double somersaults.
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POTOP, Vladimir, et Elena –. Diana SIMA. « Learning the Swimming Start by Students in Higher Education of other Profiles ». Revista Romaneasca pentru Educatie Multidimensionala 10, no 1 (2 avril 2018) : 109. http://dx.doi.org/10.18662/rrem/22.
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This paper aims to highlight how to use the computerized video analysis for learning the sports technique key elements of the start in swimming in the case of the students in higher education of other profiles. This scientific approach entailed the organization of an ascertaining experimental study, using the following research methods: bibliographic study of the specialized literature, video computerized method by means of Pinnacle Studio, Kinovea and Physics ToolKit programs, method of movement postural orientation, statistical-mathematical method which uses the KyPlot program and the method of graphical representation of results. The research was conducted from October 2017 to January 2018 and included 12 students (second-year - series no. 2) of the Faculty of General Medicine. The results of the study show the muscle strength development of arms, abdomen and legs of the students under research. The use of the video computerized method highlights and identifies the kinematic and dynamic characteristics of sports technique key elements used in swimming start regarding the launching posture, multiplication of body posture (flying through the air) and concluding body posture (entering the water). The propulsion and going out of water will be studied depending on the specific swimming style chosen by the students. The effective use of the computerized video analysis that deepens the understanding of sports technique phasic structure will allow the processing of the modern didactical programs for swimming learning. The modern research methods used in the video computerized analysis of sports technique of the start in swimming are an important help for the measurement, analysis and evaluation of the kinematic and dynamic structure of all swimming styles.
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Bartlett, Roger, Erich Müller, Stefan Lindinger, Fritz Brunner et Calvin Morriss. « Three-Dimensional Evaluation of the Kinematic Release Parameters for Javelin Throwers of Different Skill Levels ». Journal of Applied Biomechanics 12, no 1 (février 1996) : 58–71. http://dx.doi.org/10.1123/jab.12.1.58.
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This study compared three-dimensional release parameters and important features of the throwing technique for male javelin throwers of three different skill levels (elite, club, novice), recorded using three-dimensional cine or video. As expected, significant differences (p < .01) in throw distances and release speeds were found between all three groups. The only other release parameter for which a significant difference was found (between club and novice groups) was the yaw angle. The increase in release speed with increasing skill across the groups may be attributable in part to greater run-up speeds. Also important were significantly greater peak speeds of the throwing shoulder, elbow, and hand during the delivery stride for the elite group compared to the other groups. Significantly longer acceleration paths at the start of the delivery stride and a delay in elbow flexion until after final foot strike for the elite throwers were also important in generating greater release speeds.
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Russo, Caterina, Elena Puppo, Stefania Roati et Aurelio Somà. « Proposal of an Alpine Skiing Kinematic Analysis with the Aid of Miniaturized Monitoring Sensors, a Pilot Study ». Sensors 22, no 11 (4 juin 2022) : 4286. http://dx.doi.org/10.3390/s22114286.
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The recent growth and spread of smart sensor technologies make these connected devices suitable for diagnostic and monitoring in different fields. In particular, these sensors are useful in diagnostics for control of diseases or during rehabilitation. They are also extensively used in the monitoring field, both by non-expert and expert users, to monitor health status and progress during a sports activity. For athletes, these devices could be used to control and enhance their performance. This development has led to the realization of miniaturized sensors that are wearable during different sporting activities without interfering with the movements of the athlete. The use of these sensors, during training or racing, opens new frontiers for the understanding of motions and causes of injuries. This pilot study introduced a motion analysis system to monitor Alpine ski activities during training sessions. Through five inertial measurement units (IMUs), placed on five points of the athletes, it is possible to compute the angle of each joint and evaluate the ski run. Comparing the IMU data, firstly, with a video and then proposing them to an expert coach, it is possible to observe from the data the same mistakes visible in the camera. The aim of this work is to find a tool to support ski coaches during training sessions. Since the evaluation of athletes is now mainly developed with the support of video, we evaluate the use of IMUs to support the evaluation of the coach with more precise data.
Thèses sur le sujet "Video Kinematic Evaluation"
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Muzio, Francesco Paolo Lo. « Video Kinematic Evaluation : new insights on the cardiac mechanical function ». Doctoral thesis, 2022. http://hdl.handle.net/11562/1069146.
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The cardiac mechanical function plays a critical role in governing and regulating its performance under both normal and pathological conditions. The left ventricle has historically received more attention in both congenital and acquired heart diseases and was considered as the mainstay of normal hemodynamics. However, over the past few decades, there has been increasing recognition of the pivotal role of the right ventricle in determining functional performance status and prognosis in multiple conditions. Nonetheless, the ventricles should not be considered separately as they share the septum, are encircled with common myocardial fibers and are surrounded by the pericardium. Thus, changes in the filling of one ventricle may alter the mechanical function of its counterpart. This ventricular interdependence remains even after the removal of the pericardium because of constrictive pericarditis or during open chest surgery. Interestingly, during open chest surgery, only the right ventricle mechanical activity is visually checked by the surgeon and cardiologist due to the absence of an intraoperative imaging technique able to evaluate its complex function. Noteworthy, most of the imaging techniques available to clinicians are established for the assessment of the left ventricle, with the ejection fraction being the most used parameter. However, this value is a measure of global systolic function which comes short in identifying regional myocardial impairment and the mechanical contraction. Therefore, new approaches are needed to deeply investigate the mechanics of both ventricles and correctly assess the cardiac mechanical performance. In this thesis, I studied the mechanical function of the left ventricle through different modalities of cardiac magnetic resonance and employed an innovative imaging technique for the assessment of the right ventricle mechanical function during open chest surgery.
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Rozzi, Giacomo. « VIDEO KINEMATIC EVALUATION OF THE HEART (VI.KI.E.) : AN IDEA, A PROJECT, A REALITY ». Doctoral thesis, 2020. http://hdl.handle.net/11562/1017185.
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Introduction: The technological development of the last 20 years pledges the intensity of efforts for implementing novel imaging contactless modalities that accelerate the translation from the research bench to the patient bedside, especially in the cardiac field. In this work, a novel intraoperative cardiac imaging approach, named Video Kinematic Evaluation (Vi.Ki.E.), is presented and explained in detail. This technology is able to monitor, contactless, the cardiac mechanics and deformation in-situ during heart surgery. Cardiac kinematics have been deeply evaluated ranging from the experimental animal approach to the human myocardial pathologies in both left and right ventricles. Methods: Vi.Ki.E. can be defined “as simple as innovative”. It only consists of a high-speed camera placed upon an exposed beating heart in-situ to record cardiac cycles. Afterwards a tracker software is used on the recorded video to follow the epicardial tissue movements. This tracker provides information about trajectories of the epicardium and, thanks to a custom-made algorithm, the technology supplies heart mechanical information such as: Force of contraction or cardiac fatigue, Energy expenditure, Contraction velocity, displacement of the marker and epicardial torsion. This approach has been tested on 21 rats (9 ischemia/reperfusion and/or for validation, 12 for the gender difference study) and on 37 patients who underwent different surgery between 2015 and 2019. In detail 10 patients underwent Coronary Artery Bypass Grafting, 12 underwent Valve Replacement after Tetralogy of Fallot correction surgery, 6 implanted a Left Ventricular Assist Device (1 is moved in the case study section), 6 patients with Hypoplastic Heart Syndrome underwent GLENN or FONTAN surgery, 2 patients underwent Heart Transplantation and finally 1 patient underwent double valve replacement (this patient is moved into case study section). Results: The patients’ results demonstrated that the Vi.Ki.E. technology was able to discriminate, with statistic potency, the kinematic differences before and after the surgery in real-time, suggesting possible clinical implications in the treatment of the patients before the chest closure and/or in the intensive care unit. As it concerns the experimental animals, the results are the basics of the validation technology. Some of them were used as accepted model in comparison with the Vi.Ki.E. results on patients. Conclusions: In conclusion, this study has shown that Vi.Ki.E. is a safe and contactless technology with promising possible clinical application. The ease in the evaluation and the algorithm-based approach makes Video Kinematic Evaluation a widespread technique from cellular level to human cases covering the entire experimental field with in-vivo evaluation and possibly Langendorff/Working Heart approaches.
Chapitres de livres sur le sujet "Video Kinematic Evaluation"
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Rohwedder, Thomas. « Biomechanics of the Canine Elbow Joint ». Dans Veterinary Medicine and Science. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99569.
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The canine elbow joint is a complex joint, whose musculoskeletal anatomy is well investigated. During the last 30 years kinematic analysis has gained importance in veterinary research and kinematics of the healthy and medial coronoid disease affected canine elbow joint are progressively investigated. Video-kinematographic analysis represents the most commonly used technique and multiple studies have investigated the range of motion, angular velocity, duration of swing and stance phase, stride length and other kinematic parameters, mostly in the sagittal plane only. However, this technique is more error-prone and data gained by video-kinematography represent the kinematics of the whole limb including the soft tissue envelope. A more precise evaluation of the in vivo bone and joint movement can only been achieved using fluoroscopic kinematography. Based on recent studies significant differences in the motion pattern between healthy joints and elbows with medial coronoid disease could be detected. Thereby not only adaptive changes, caused by pain and lameness, could be described, but primary changes in the micromotion of the joint forming bones could be found, which potentially represent new factors in the pathogenesis of medial coronoid disease. This chapter gives a review of current literature on elbow joint kinematics, with particular focus onto pathologic biomechanics in dysplastic canine elbows.
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Annett, Michelle, Fraser Anderson et Walter F. Bischof. « Activities and Evaluations for Technology-Based Upper Extremity Rehabilitation ». Dans Advances in Medical Technologies and Clinical Practice, 307–38. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9740-9.ch015.
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Recent advances in projection and sensing have resulted in an increased adoption of virtual reality, video games, and interactive interfaces to improve patient compliance with rehabilitation programs. In this chapter, we describe the application of multi-touch tabletop surfaces to physical and occupational rehabilitation programs that are focused on the upper extremities. First, we detail the participatory design processes undertaken with local physical and occupational therapists to design and integrate a ‘patient-friendly' multi-touch tabletop system in their workplace. We then explore the design considerations that informed the development of a suite of sixteen multi-touch interactive activities. The design considerations highlighted the need for customization and flexibility in the software, as well as the importance of supporting a variety of activity types. We then detail the laboratory-based methods that were used to evaluate the efficacy of the activity interventions as well as our deployment of the system in a local rehabilitation hospital. Our evaluation, which employed both qualitative and quantitative components (i.e., the Intrinsic Motivation Inventory, semi-structured interviews, kinetics and kinematics recorded from motion trackers and an electromyogram recorder), determined that it is the design of activities, rather than the utilization of technology itself, that impacts the success of technology-assisted rehabilitation. The chapter concludes with a discussion of the implications of our system and its deployment.
Actes de conférences sur le sujet "Video Kinematic Evaluation"
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Sandlund, Marlene, Helena Grip, Charlotte Hager, Erik Domellof et Louise Ronnqvist. « Low-cost motion interactive video games in home training for children with cerebral palsy : A kinematic evaluation ». Dans 2011 International Conference on Virtual Rehabilitation (ICVR). IEEE, 2011. http://dx.doi.org/10.1109/icvr.2011.5971854.
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Dimitrova, Nikolina, Anna Nikolova et Hristo Pavlov. « BIOMECHANICAL EVALUATION OF MOTOR ACTIONS AT THE GRIP “SHOULDER THROW” IN THE SPORT OF WRESTLING ». Dans INTERNATIONAL SCIENTIFIC CONGRESS “APPLIED SPORTS SCIENCES”. Scientific Publishing House NSA Press, 2022. http://dx.doi.org/10.37393/icass2022/85.
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ABSTRACT An “active” experiment was performed for kinematic and dynamographic analysis of the motor actions at one of the main wrestling grips “shoulder throw”. The general principles of ensuring the success of the grip as well as the individual features demonstrated in the performances of elite athletes are traced. The purpose of this study is to explore and perform a biomechanical analysis of the grip “Shoulder throw”. The kinematic characteristics are assessed quantitatively by using a video-computer methodology, and the dynamic ones by measuring the support reactions on a dynamo platform. The object of the study are fighters for whom “shoulder throw” is the main grip. Both general biomechanical regularities and significant individual features in sports and technical mastery have been experimentally derived. The obtained results raise questions before the training process regarding the measure between the standardization and individualization of sports and technical mastery. In our opinion, these results are of great interest as they reveal a new and sensitive indicator for the coordination abilities and respectively for the sports and technical mastery of the athletes.
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Silva, Miguel, et Jorge Ambro´sio. « Gait Analysis Using Multibody Simulation Tools and Inverse Dynamics Procedures ». Dans ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-84839.
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The use of inverse dynamics methodologies for the evaluation of intersegmental reaction forces and the moments-of-force at the anatomical joints, in the framework of gait analysis, not only requires that appropriate biomechanical models are used but also that kinematic and kinetic data sets are available. This paper discusses the quality of the results of the inverse dynamics analysis with respect to the filtering procedures used and the kinematic consistency of the position, velocity and acceleration data. A three-dimensional whole body response biomechanical model based on a multibody formulation with natural coordinates is used. The model has 16 anatomical segments that are described using 33 rigid bodies in a total of 44 degrees-of-freedom. In biomechanical applications, one of the advantages of the current formulation is that the set of anatomical points used to reconstruct the spatial motion of the subject is also used to construct the set of natural coordinates that describe the biomechanical model itself. Based on the images collected by four synchronized video cameras, the three-dimensional trajectories of the anatomical points are reconstructed using standard photogrammetry techniques and Direct Linear Transformations. The trajectories obtained are then filtered in order to reduce the noise levels introduced during the reconstruction procedure using 2nd order Butterworth low-pass filters with properly chosen cut-off frequencies. The filtered data is used in the inverse dynamics analysis either directly or after being modified in order to ensure its consistency with the biomechanical model’s kinematic constraints. It is also shown that the use of velocities and accelerations consistent with the kinematic constraints or those obtained through the time derivatives of the spline interpolation curves of the reconstructed trajectories lead to similar results.
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Meyer, Steven E., Brian Herbst, Stephen Forrest, Anthony Sances et Srirangam Kumaresan. « Design and Evaluation of a System for Testing and Analysis of Rollovers With Narrow Objects ». Dans ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43104.
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Recent statistics highlight the significant risk of serious and fatal injuries to occupants involved in rollover collisions due to excessive roof crush. The government has reported that in 2002, Sports Utility Vehicle rollover related fatalities increased by 14% to more than 2400 annually. 61% of all SUV fatalities included rollovers. [1] Rollover crashes rely primarily upon the roof structures to maintain occupant survival space. Frequently these crashes occur off the travel lanes of the roadway and, therefore, can include impacts with various types of narrow objects such as light poles, utility poles and/or trees. A test device and methodology is presented which allows for dynamic, repeatable rollover impact evaluation of complete vehicle roof structures with such narrow objects. These tests allow for the incorporation of Anthropomorphic Test Dummies (ATDs) which can be instrumented to measure accelerations, forces and moments to evaluate injury potential. High-speed video allows for detailed analysis of occupant kinematics and evaluation of injury causation. Criteria such as restraint performance, injury potential, survival space and the effect of roof crush associated with various types of design alternatives, countermeasures and impact circumstances can also be evaluated. In addition to presentation of the methodology, two representative vehicle crash tests are also reported. Results indicated that the reinforced roof structure significantly reduced the roof deformation compared to the production roof structure.
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Quercetti, Thomas, Andre Musolff et Karsten Mu¨ller. « Instrumented Measurements on Radioactive Waste Disposal Containers During Experimental Drop Testing ». Dans ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59142.
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In context with disposal container safety assessment of containers for radioactive waste the German Federal Institute for Materials Research and Testing (BAM) performed numerous drop tests in the last years. The tests were accompanied by extensive and various measurement techniques especially by instrumented measurements with strain gages and accelerometers. The instrumentation of a specimen is an important tool to evaluate its mechanical behavior during impact. Test results as deceleration-time and strain-time functions constitute a main basis for the validation of assumptions in the safety analysis and for the evaluation of calculations based on finite-element methods. Strain gauges are useful to determine the time dependent magnitude of any deformation and the associated stresses. Accelerometers are widely used for the measuring of motion i.e. speed or the displacement of the rigid cask body, vibration and shock events. In addition high-speed video technique can be used to visualize and analyze the kinematical impact scenario by motion analysis. The paper describes some selected aspects on instrumented measurements and motion analysis in context with low level radioactive waste (LLW) container drop testing.
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Lall, Pradeep, Dhananjay Panchagade, Prakriti Choudhary, Jeff Suhling et Sameep Gupte. « Models for Shock and Vibration Survivability of Electronic and MEMS Packaging ». Dans ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73427.
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Product level assessment of drop and shock reliability relies heavily on experimental test methods. Prediction of drop and shock survivability is largely beyond the state-of-art. However, the use of experimental approach to test out every possible design variation, and identify the one that gives the maximum design margin is often not feasible because of product development cycle time and cost constraints. Presently, one of the primary methodologies for evaluating shock and vibration survivability of electronic packaging is the JEDEC drop test method, JESD22-B111 which tests board-level reliability of packaging. However, packages in electronic products may be subjected to a wide-array of boundary conditions beyond those targeted in the test method. In this paper, a failure-envelope approach based on wavelet transforms and damage proxies has been developed to model drop and shock survivability of electronic packaging. Data on damage progression under transient-shock and vibration in both 95.5Sn4.0Ag0.5Cu and 63Sn37Pb ball-grid arrays has been presented. Component types examined include — flex-substrate and rigid substrate ball-grid arrays. Dynamic measurements like acceleration, strain and resistance are measured and analyzed using high-speed data acquisition system capable of capturing in-situ strain, continuity and acceleration data in excess of 5 million samples per second. Ultra high-speed video at 150,000 fps per second has been used to capture the deformation kinematics. The concept of relative damage index has been used to both evaluate and predict damage progression during transient shock. The failure-envelope provides a fundamental basis for development of component integration guidelines to ensure survivability in shock and vibration environments at a user-specified confidence level. The approach is scalable to application at system-level. Explicit finite-element models have been developed for prediction of shock survivability based on the failure envelope. Model predictions have been correlated with experimental data for both leaded and leadfree ball-grid arrays.
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Lall, Pradeep, Dhananjay Panchagade, Prakriti Choudhary, Jeff Suhling et Sameep Gupte. « Shock and Vibration Survivability Prediction Using Failure Envelopes for Electronic and MEMS Packaging ». Dans ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-82612.
Texte intégralRésumé :
Product level assessment of drop and shock reliability relies heavily on experimental test methods. Prediction of drop and shock survivability is largely beyond the state-of-art. However, the use of experimental approach to test out every possible design variation, and identify the one that gives the maximum design margin is often not feasible because of product development cycle time and cost constraints. Presently, one of the primary methodologies for evaluating shock and vibration survivability of electronic packaging is the JEDEC drop test method, JESD22-B111 which tests board-level reliability of packaging. However, packages in electronic products may be subjected to a wide-array of boundary conditions beyond those targeted in the test method. In this paper, a failure-envelope approach based on wavelet transforms and damage proxies has been developed to model drop and shock survivability of electronic packaging. Data on damage progression under transient-shock and vibration in both 95.5Sn4.0Ag0.5Cu and 63Sn37Pb ball-grid arrays has been presented. Component types examined include — flex-substrate and rigid substrate ball-grid arrays. Dynamic measurements like acceleration, strain and resistance are measured and analyzed using high-speed data acquisition system capable of capturing in-situ strain, continuity and acceleration data in excess of 5 million samples per second. Ultra high-speed video at 150,000 fps per second has been used to capture the deformation kinematics. The concept of relative damage index has been used to both evaluate and predict damage progression during transient shock. The failure-envelope provides a fundamental basis for development of component integration guidelines to ensure survivability in shock and vibration environments at a user-specified confidence level. The approach is scalable to application at system-level. Explicit finite-element models have been developed for prediction of shock survivability based on the failure envelope. Model predictions have been correlated with experimental data for both leaded and leadfree ball-grid arrays.