Relevant bibliographies by topics / Biomechanické limity

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Biomechanické limity'

Author: Grafiati
Published: 4 June 2021
Last updated: 11 February 2022

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Journal articles on the topic "Biomechanické limity"

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Karzilov, A. I. "The respiratory system biomechanical homeostasis and its maintenance mechanisms in normal conditions and at obstructive pulmonary diseases." Bulletin of Siberian Medicine 6, no. 1 (March 30, 2007): 13–38. http://dx.doi.org/10.20538/1682-0363-2007-1-13-38.

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Parameters of breathing biomechanics in healthy persons (n = 20), patients with bronchial asthma (n = 30) and chronic obstruc-tive pulmonary disease (n = 30) are analyzed during electrical stimulation of the diaphragm. Methodology of homeostatic parame-ters searching and their classification is offered. Descriptive and comparative analyses are performed. Homeostatic parameters of biomechanics describing the condition of elastic and non -elastic properties of respiratory system, of respiratory muscles, of general pulmonary hysteresis, breathing regulation are differentiated. Basic homeostatic parameter is the ratio of inspiratory capacity to the lungs elastic recoil. The model of lungs with the biomechanical buffer and retractive-elastic- surfactant complex of lungs is offered. Biomechanical homeostasis idea of respiratory system as ability of an organism to support in dynamics balance normal and patho-logical conditions essentially important for preservation of respiratory system biomechanical parameters in admissible limits is for-mulated.
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Roe, Simon. "Understanding the Limits of Biomechanical Testing." Veterinary and Comparative Orthopaedics and Traumatology 31, no. 02 (February 2018): vi—vii. http://dx.doi.org/10.1055/s-0038-1637025.

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Al-Eisawi, Khaled W., Carter J. Kerk, and Jerome J. Congleton. "Wrist strength limitations to manual exertion capability." Occupational Ergonomics 1, no. 2 (April 1, 1998): 107–21. http://dx.doi.org/10.3233/oer-1998-1203.

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This study evaluated wrist strength limitations to manual exertion capability in two-dimensional static biomechanical modeling. The researchers hypothesized that wrist strength does not limit manual exertion capability - an assumption commonly made in many strength biomechanical models. An experiment was conducted on 15 right-handed males of college age. Isometric wrist flexion strength was measured at two elbow angles: 90 degree and 135 degree and in two wrist positions: neutral and 45 degree extended. Isometric wrist radial deviation strength was measured at the same two elbow angles and in two wrist positions: neutral and 30 degree ulnarly deviated. Minimum wrist strength limits for which wrist strength does not limit maximal moments about the elbow in manual hand exertions were calculated and compared to their corresponding measured wrist strength moments using paired t-tests. In general, wrist strength was non-limiting. However, wrist flexion strength in the 45 degree extended wrist posture was limiting. Weak-wrist subjects showed more wrist strength limitations than strong-wrist subjects.
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Leitner, Christoph, Pascal A. Hager, Harald Penasso, Markus Tilp, Luca Benini, Christian Peham, and Christian Baumgartner. "Ultrasound as a Tool to Study Muscle–Tendon Functions during Locomotion: A Systematic Review of Applications." Sensors 19, no. 19 (October 5, 2019): 4316. http://dx.doi.org/10.3390/s19194316.

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Movement science investigating muscle and tendon functions during locomotion utilizes commercial ultrasound imagers built for medical applications. These limit biomechanics research due to their form factor, range of view, and spatio-temporal resolution. This review systematically investigates the technical aspects of applying ultrasound as a research tool to investigate human and animal locomotion. It provides an overview on the ultrasound systems used and of their operating parameters. We present measured fascicle velocities and discuss the results with respect to operating frame rates during recording. Furthermore, we derive why muscle and tendon functions should be recorded with a frame rate of at least 150 Hz and a range of view of 250 mm. Moreover, we analyze why and how the development of better ultrasound observation devices at the hierarchical level of muscles and tendons can support biomechanics research. Additionally, we present recent technological advances and their possible application. We provide a list of recommendations for the development of a more advanced ultrasound sensor system class targeting biomechanical applications. Looking to the future, mobile, ultrafast ultrasound hardware technologies create immense opportunities to expand the existing knowledge of human and animal movement.
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Al-Eisawi, Khaled W., Carter J. Kerk, and Jerome J. Congleton. "Limitations of Wrist Strength to Manual Exertion Capability in 2D Biomechanical Modeling." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 38, no. 10 (October 1994): 559–63. http://dx.doi.org/10.1177/154193129403801004.

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The objective of this study is to evaluate the assumption in biomechanical models that wrist strength does not limit manual exertion capability. An experiment was designed and run on right-handed males to test isometric elbow flexion strength at two included elbow angles: 90° and 135° and in two forearm positions: supinated and mid between supination and pronation. Isometric wrist flexion strength was also measured at the same elbow angles and at two wrist positions in the flexion/extension plane: neutral and 45° extended. Isometric wrist radial deviation strength was measured at the same two elbow angles and at two wrist positions in the radial/ulnar deviation plane: neutral and 30° ulnarly deviated. An equation was developed to calculate the theoretical minimum wrist strength limits for which wrist strength does not limit maximal moments about the elbow. These calculated limits were compared to the corresponding measured wrist strength moments. In general, wrist strength was found to be non-limiting, but in some specific circumstances, it can be limiting. Among the posture/exertion combinations tested, only wrist flexion strength in the extended wrist posture was found to be limiting. There was some evidence that strong-wrist people show less wrist strength limitations than weak-wrist people in some postures. It was also found that the neutral wrist posture is not associated with the highest wrist strength.
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Bonnette, Scott, Christopher A. DiCesare, Adam W. Kiefer, Michael A. Riley, Kim D. Barber Foss, Staci Thomas, Katie Kitchen, Jed A. Diekfuss, and Gregory D. Myer. "Injury Risk Factors Integrated Into Self-Guided Real-Time Biofeedback Improves High-Risk Biomechanics." Journal of Sport Rehabilitation 28, no. 8 (November 1, 2019): 831–39. http://dx.doi.org/10.1123/jsr.2017-0391.

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Context:Existing anterior cruciate ligament (ACL) injury prevention programs have failed to reverse the high rate of ACL injuries in adolescent female athletes.Objective:This investigation attempts to overcome factors that limit efficacy with existing injury prevention programs through the use of a novel, objective, and real-time interactive visual feedback system designed to reduce the biomechanical risk factors associated with ACL injuries.Design:Cross-over study.Setting:Medical center laboratory.Participants:A total of 20 females (age = 19.7 [1.34] y; height = 1.74 [0.09] m; weight = 72.16 [12.45] kg) participated in this study.Methods:Participants performed sets of 10 bodyweight squats in each of 8 training blocks (ie, 4 real-time and 4 control blocks) and 3 testing blocks for a total of 110 squats. Feedback conditions were blocked and counterbalanced with half of participants randomly assigned to receive the real-time feedback block first and half receiving the control (sham) feedback first.Results:Heat map analysis revealed that during interaction with the real-time feedback, squat performance measured in terms of key biomechanical parameters was improved compared with performance when participants squatted with the sham stimulus.Conclusions:This study demonstrates that the interactive feedback system guided participants to significantly improve movement biomechanics during performance of a body weight squat, which is a fundamental exercise for a longer term ACL injury risk reduction intervention. A longer training and testing period is necessary to investigate the efficacy of this feedback approach to effect long-term adaptations in the biomechanical risk profile of athletes.
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Deban, Stephen M., Roi Holzman, and Ulrike K. Müller. "Suction Feeding by Small Organisms: Performance Limits in Larval Vertebrates and Carnivorous Plants." Integrative and Comparative Biology 60, no. 4 (July 13, 2020): 852–63. http://dx.doi.org/10.1093/icb/icaa105.

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Abstract Suction feeding has evolved independently in two highly disparate animal and plant systems, aquatic vertebrates and carnivorous bladderworts. We review the suction performance of animal and plant suction feeders to explore biomechanical performance limits for aquatic feeders based on morphology and kinematics, in the context of current knowledge of suction feeding. While vertebrates have the greatest diversity and size range of suction feeders, bladderworts are the smallest and fastest known suction feeders. Body size has profound effects on aquatic organismal function, including suction feeding, particularly in the intermediate flow regime that tiny organisms can experience. A minority of tiny organisms suction feed, consistent with model predictions that generating effective suction flow is less energetically efficient and also requires more flow-rate specific power at small size. Although the speed of suction flows generally increases with body and gape size, some specialized tiny plant and animal predators generate suction flows greater than those of suction feeders 100 times larger. Bladderworts generate rapid flow via high-energy and high-power elastic recoil and suction feed for nutrients (relying on photosynthesis for energy). Small animals may be limited by available muscle energy and power, although mouth protrusion can offset the performance cost of not generating high suction pressure. We hypothesize that both the high energetic costs and high power requirements of generating rapid suction flow shape the biomechanics of small suction feeders, and that plants and animals have arrived at different solutions due in part to their different energy budgets.
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JHOU, SHU-YU, KAO-SHANG SHIH, PO-SHENG HUANG, FANG-YU LIN, and CHING-CHI HSU. "BIOMECHANICAL ANALYSIS OF DIFFERENT SURGICAL STRATEGIES FOR THE TREATMENT OF ROTATIONALLY UNSTABLE PELVIC FRACTURE USING FINITE ELEMENT METHOD." Journal of Mechanics in Medicine and Biology 19, no. 02 (March 2019): 1940015. http://dx.doi.org/10.1142/s0219519419400153.

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A rotationally unstable pelvic fracture can lead to loss of function and limit moving ability. Immediate fracture fixation is needed for patients with the pelvic fractures. However, it may be difficult to evaluate different surgical strategies for the fracture treatments due to variations in patients’ anatomies and surgical techniques. Thus, the purpose of the present study was to analyze the biomechanical performances of the intact, injured, and treated pelvises based on different physiological movements of the spine using finite element method. Three-dimensional musculoskeletal finite element models of the spine-pelvis-femur complex were developed. The intact pelvis, the rotationally unstable pelvis, and six types of pelvic fixation techniques were analyzed. Additionally, seven types of physiological movements of the spine were also considered. The results showed that the posterior iliosacral screws combined with lower and anterior plate (PIS-LAP) had good fixation stability, lower plate stress, and lower pelvic stress. However, the PIS-LAP increased the stress of the posterior iliosacral screws. The right lateral bending, left lateral bending, and flexion significantly affect all the biomechanical performances compared to the other physiological movements of the spine. The present study can provide engineers and surgeons with the understanding of the biomechanics of various fixation techniques during different physiological movements for the treatment of rotationally unstable pelvic fractures.
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Byrd, Charisma, and MinHyuk Kwon. "The Effect of Hand-Held Technology on Thumb Biomechanics." Journal of Health, Sports, and Kinesiology 2, no. 1 (January 31, 2021): 7–8. http://dx.doi.org/10.47544/johsk.2021.2.1.7.

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The rise of portable units calls attention to the impact of device design and it challenges to biomechanical capabilities of the thumb and increased musculoskeletal discomfort. The purpose of this critiqued article, therefore, is to understand the significance of thumb biomechanics on hand-held technology and upper extremity pain. Healthy sixteen right-handed participants (21-40 years) performed a multitude of swiping gestures with the thumb of their right hand on 8’’ and 10’’ tablets (Samsung Galaxy III). The swiping gestures differed in swipe direction (outward v. inward), swipe orientation (horizontal v. vertical), swipe location (4 swipe zones), and swipe length (short v. long). Data was acquired using a custom Android application, thumb/wrist posture and forearm muscle activity was quantified using three-dimensional motion analysis and surface electromyograph, respectively. Data was analyzed using repeated measures of ANOVA. Self-reported perceived wrist and hand discomfort was measured using a visual analogue scale after each trial. Swiping actions closest to the palm rendered less pain, decreased forearm muscle activity, neutral thumb biomechanics and wrist posture. The left zones had greatest metacarpal (16) and carpometacarpal abduction (10) and topmost wrist movement, ulnar deviation (18) and extension (14) (Table 1), compared to the right zones. Regarding tablet orientation, portrait mode of both devices amassed more muscle activity related to landscape mode. The limits of upper extremities and thumb biomechanics can be seen in specific swipe locations of hand-held technology. The p-values for wrist extension (p < 0.01) and ulnar deviation (p < 0.03) on tablet size and orientation quantitatively illustrate the poor wrist posture commonly adopted by users under these conditions. Swipe zone results proved users had best performance and lower discomfort rates when gestures were performed near the palm. Carpometacarpal abduction data found high joint angles during trials on the left side of the tablet and no movement (0) on the right side. This constant biomechanical exertion to swipe in out-of-reach areas may lead to musculoskeletal disorders or pain. The results suggest tablet hardware and user interface design to allow for neutral thumb and wrist posture while accounting for decreased muscle demands. The purpose of the study was to identify the effect of hand-held technology on thumb biomechanics, thumb/wrist posture, and forearm muscle activity. The findings demonstrated increased user performance and lower musculoskeletal pain while performing gestures closer to the palm. The authors’ ability to pinpoint the specific location where users experienced greatest extension, abduction, pain, and forearm muscle activation (top left zone) was one of the articles supreme strengths. Nonetheless, the study should be considered within context of its limitations. A limitation within the experiment was the criteria to be a participant. The study did not inquire about the amount of time users usually spent on their device in a normal week, this may give evidence to the biomechanical loads their thumb and upper extremities are accustomed to. A suggestion for research design is to improve participant criterion. Users thumb strength can be quantified with the pinch test or examined through manual muscle tests to indicate a correlation between thumb strength and participant perception of fatigue post-trial(s).
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KAMAL, ZEINAB, and GHOLAMREZA ROUHI. "A PARAMETRIC INVESTIGATION OF THE EFFECTS OF CERVICAL DISC PROSTHESES WITH UPWARD AND DOWNWARD NUCLEI ON SPINE BIOMECHANICS." Journal of Mechanics in Medicine and Biology 16, no. 07 (November 2016): 1650092. http://dx.doi.org/10.1142/s0219519416500925.

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This work aimed at investigating the influence of Baguera and Discocerv cervical disc prostheses, with mobile downward center of rotation (COR) and fixed upward COR, respectively, on the biomechanical behavior of C4–C6 cervical spine. For this purpose, using computed tomography (CT) data, a parametric nonlinear finite element (FE) model of intact C4–C6 spinal segments was developed, and an artificial disc was implanted at C5–C6 level. To assess the influence of implants on the biomechanics of cervical spine, the FE models were analyzed in flexion, extension, lateral bending, and axial rotation, and the results were presented in the range of motion (ROM) curves, and torsional stiffness. Results of this study, in agreement with the literature, suggested that both Baguera and Discocerv implants might be able to preserve the motion, and limit the alteration of the biomechanics of adjacent levels. Except for the possible confliction of adjacent vertebrae at the implanted level with Baguera implant in lateral bending, results of this study also indicated that the movability and downward COR of Baguera disc prosthesis caused ROMs of the implanted segment to be more similar to the intact model than Discocerv implant. Moreover, the upward COR of Discocerv implant may result in over-distraction on facets in the maximal flexion, with the ratio of 1.22 versus 1.36, and consequently facet syndrome during extension for Bageura and Discocerv disc prostheses, respectively.
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Dissertations / Theses on the topic "Biomechanické limity"

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Kučera, Jonáš. "Normativní požadavky na činnost zádržných systémů vozidel." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-232513.

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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.
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Reinert, Senia Smoot. "Enhancing Posturography Stabilization Analysis and Limits of Stability Assessment." University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1470227622.

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Bowtell, Mark Vincent. "Biomechanical limits to running speed in humans." Thesis, Royal Veterinary College (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519517.

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Capo-Lugo, Carmen Enid. "Neuromechanical Factors That Limit Walking Speed in Individuals with Post-Stroke Hemiparesis." Thesis, Northwestern University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3626475.

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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.

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Mettler, Jeff H. "THE EFFECTS OF A HIP FLEXOR STRETCHING PROGRAM ON RUNNING KINEMATICS IN INDIVIDUALS WITH LIMITED PASSIVE HIP EXTENSION." UKnowledge, 2016. http://uknowledge.uky.edu/khp_etds/35.

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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.
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Davies, Nocole J. "Advancing problem solving at the limits of animal locomotion : rules, tools and the clarification of the biomechanics of the extinct Thecodontosaurus antiquus." Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441313.

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Azevedo, Fábio Micolis de. "Avaliação do sinal eletromiográfico como parâmetro para determinação do limiar de fadiga muscular." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/39/39132/tde-08082008-163407/.

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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
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Filipowicz, Dean. "A Biomechanical Comparison of 3.5 Locking Compression Plate Fixation to 3.5 Limited Contact Dynamic Compression Plate Fixation in a Canine Cadaveric Distal Humeral Metaphyseal Gap Model." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/33558.

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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
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Steinmann, Thomas. "Métrologie optique en dynamique des fluides appliquées à l'écologie physique des insectes." Thesis, Tours, 2017. http://www.theses.fr/2017TOUR4050/document.

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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
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Chen, Jade Ashley. "The Effects of Worker Age on Lifting: Psychophysical Estimates of Acceptable Loads and their Link to Biomechanics." Thesis, 2012. http://hdl.handle.net/10012/7051.

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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.
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Books on the topic "Biomechanické limity"

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Gasser, T. Christian. Physical processes in the vessel. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198755777.003.0003.

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Evolution has developed a complex cardiovascular system, the analysis of which involves many physical disciplines. Specifically, cardiovascular function critically depends on the proper interaction between blood and the vessel wall, such that haemodynamics-based biomechanical factors are a common denominator of cardiovascular pathologies. This chapter reviews biomechanics-related physical processes in the vessel. Specifically, mechanical load transition mechanisms in blood and the vessel wall, blood-wall interaction phenomena, as well as simple analytical solutions to Newton’s second law of mechanics are discussed. Albeit that such simple analytical relations are very useful when exploring physical processes in the vasculature, their application is limited and cardiovascular analysis often requires more advanced computational methods so as to draw conclusions from Newton’s law. Most important, the proper application of either simple or more advanced physical models requires close interaction between engineering and medical disciplines.
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Young, Brian A., Phillip S. Sizer, and Miles Day. Thoracic Facet Dysfunction/Costotransverse Joint Pathology. Edited by Mehul J. Desai. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199350940.003.0010.

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The thoracic facet and costotransverse joints are often implicated as the source of thoracic pain, yet definitive diagnostic and treatment guidance is significantly limited. This chapter reviews the anatomy, innervation, and biomechanics of these joints, as well as associated pathology. Definitive innervation of the posterior primary rami has yet to be established, and significant pain pattern overlap between the thoracic facet joint, costotransverse joints, and visceral referral patterns, as well as the limitations of current biomechanics, challenge the clinician’s ability to examine pain of suspected thoracic origin. The use of clinical reasoning in the absence of definitive diagnostic and treatment approaches is necessary to optimize outcomes in patients with pain of suspected thoracic musculoskeletal origin. A progression from noninvasive to minimally invasive to interventional techniques may be warranted based on the patient’s response to treatment.
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Lories, Rik J., and Georg Schett. Pathology: bone. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780198734444.003.0010.

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Axial spondyloarthritis is associated with different types of skeletal damage. Inflammation at the affected sites is linked with both loss of trabecular bone and new bone formation on the cortical side, potentially leading to joint or spine ankylosis. Both aspects of the disease can result in a significant burden for the patient. Bone loss is directly linked to proinflammatory cytokines and activation of osteoclasts. Control of inflammation is therefore the best strategy to prevent loss of bone. The nature of the new bone formation process is less defined. A prominent role for developmental signalling pathways has been proposed. Current therapies have limited or no impact on this process. However, emerging data suggest that early control of disease activity may be part of a window of opportunity to prevent structural damage, as biomechanical factors and instability following inflammation may also play a role.
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Treiber, Kyle. Biosocial Criminology and Models of Criminal Decision Making. Edited by Wim Bernasco, Jean-Louis van Gelder, and Henk Elffers. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199338801.013.4.

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This chapter explores how integrating the science of criminal decision making and contemporary biosocial criminology can benefit our understanding of why people make criminal action decisions and the role of biological factors. It reviews relevant biosocial findings but argues that efforts to link them to criminal decision making are limited by the lack of a strong model of the action process. It then compares how key components of this process—motivation, perception, and choice—are portrayed in models of criminal decision making with what is currently known about their biomechanics. It concludes that models of criminal decision making would benefit from the integration of evidence from the biological sciences and that some common assumptions may need to be reconsidered. It argues that biosocial criminology would benefit from a stronger, more biologically informed model of criminal decision making, which could better explain the role of biological factors in crime causation.
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Arena, Ross, Dejana Popovic, Marco Guazzi, Amy McNeil, and Michael Sagner. Cardiovascular response to exercise. Edited by Guido Grassi. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0026.

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The body’s response to an exertional stimulus, if performed adequately to meet the imposed demand, is an orchestrated response predominantly among the cardiovascular, pulmonary, and skeletal systems. These physiological systems work together to ensure that up-titrated energy and force production demands are met. The magnitude of the exertional stimulus these systems are able to respond to, when an individual is in a true state of physiological health, is influenced by multiple factors including age, sex, biomechanics, genomics, and exercise training history. When one or more of these systems suffers from dysfunction, as is the case when an individual is at risk for (i.e. unhealthy lifestyle history) or diagnosed with a chronic disease, the response to a physical stimulus ultimately fails and exertional capacity is limited. There is a clear and well-established clinical relevance to the cardiovascular response to an exertional stimulus, commonly assessed through a graded aerobic exercise test on a treadmill or cycle ergometer. In fact, aerobic capacity has been referred to a key vital sign. We are also gaining an appreciation of how communication and presentation of information between health professionals and individuals receiving care significantly impacts comprehension and adherence to a plan of care. This chapter addresses these areas, beginning with a brief granular description of exertional cardiovascular physiology, transitioning to practical clinical implications of this information for health professionals, and ending with how the individuals seeking healthcare receive, process, and comprehend this information with the ultimate goal being real-world application and improved health outcomes.
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Book chapters on the topic "Biomechanické limity"

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Cordey, J. R., and S. M. Perren. "Limits of Plate on Bone Friction in Internal Fixation of Fractures." In Biomechanics: Basic and Applied Research, 393–98. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3355-2_53.

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Mummolo, Carlotta, and Giulia Vicentini. "Limits of Dynamic Postural Stability with a Segmented Foot Model." In Lecture Notes in Computational Vision and Biomechanics, 256–70. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-43195-2_21.

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Erverdi, Nejat, Mustafa Burhan Ateş, and Melih Motro. "Expanding the Limits for Esthetic Strategies by Skeletal Anchorage." In Esthetics and Biomechanics in Orthodontics, 391–410. Elsevier, 2015. http://dx.doi.org/10.1016/b978-1-4557-5085-6.00019-9.

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Saltzman, W. Mark. "Cell and Tissue Mechanics." In Tissue Engineering. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195141306.003.0010.

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Mechanics is the branch of physics that is concerned with the action of forces on matter. Tissue engineers can encounter mechanics in various settings. Often, the mechanical properties of replacement biological materials must replicate the normal tissue: for example, there is limited use for a tissue-engineered bone that cannot support the load encountered by its natural counterpart. In addition, the mechanical properties of cells and cell–cell adhesions can determine the architecture of a tissue during development. This phenomenon can sometimes be exploited, since the final form of engineered tissues depends on the forces encountered during assembly and maturation. Finally, the mechanics of individual cells—and the molecular interactions that restrain cells—are important determinants of cell growth, movement, and function within an organism. This chapter introduces the basic elements of mechanics applied to biological systems. Some examples of biomechanical principles that appear to be important for tissue engineering are also provided. For further reading, comprehensive treatments of various aspects of biomechanics are also available. Consider an elongated object—for example, a segment of a biological tissue or a synthetic biomaterial—that is fixed at one end and suddenly exposed to a constant applied load. The material will change or deform in response to the load. For some materials, the deformation is instantaneous and, under conditions of low loading, deformation varies linearly with the magnitude of the applied force: . . . σ[≡F/A]= Eε (5-1) . . . where σ is the applied stress and ε is the resulting strain. This relationship is called Hooke’s law, after the British physicist Robert Hooke, and it describes the behavior of many elastic materials, such as springs, which deform linearly upon loading and recover their original shape upon removal of the load. The Young’s modulus or tensile elastic modulus, E, is a property of the material; some typical values are provided in Table 5.1. Not all elastic materials obey Hooke’s law (for example, rubber does not); some materials will recover their original shape, but strain is not linearly related to stress. Fortunately, many interesting materials do follow Equation 5-1, particularly if the deformations are small.
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del Pilar, Maria, A. M. Rodriguez, and C. Gomes. "Modelling of the Human Skull Including Loading, Determination of the Limit Load and Fracture Prediction." In Computer Methods in Biomechanics & Biomedical Engineering – 2, 753–60. CRC Press, 2020. http://dx.doi.org/10.1201/9781003078289-100.

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"Figure 12.5 Schematic of the trauma shown in Figures 12.2 and 12.3. The spine starts in a neutral position (NP). The 50 to 75 ms time period illustrates the neck forming an S-shaped curvature (Phase I). During this phase, the lower cervical spine intervertebral joints exhibit hyper-extension, exceeding their physiological limits. In the later phase (Phase II), the spine transforms to a C-shape with complete extension. This phase is associated with a lesser degree of the lower level hyper-extension, and thus a lesser potential for injury." In Biomechanics in Ergonomics, 277–84. CRC Press, 1999. http://dx.doi.org/10.4324/9780203016268-66.

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Leite, Larissa de Oliveira Matia, Alexandre Minoru Sasaki, Rosimeire Sedrez Bitencourt, Maria Lucia Miyake Okumura, and Osiris Canciglieri Junior. "Humanization and Macroergonomics: An Analysis in the Billing Sector of a University Hospital in Paraná." In Advances in Transdisciplinary Engineering. IOS Press, 2020. http://dx.doi.org/10.3233/atde200078.

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The humanization of organizations is a trend in companies that have a vision of the future aligned with the needs of the market. In the health area, this humanization should not be limited to its users, but include the employees involved in the work system. The human aspect and its relations with the work system is a focus of studying ergonomics, which in its macroergomic approach aims at integrating organization-man-machine systems into a sociotechnical and participatory context. This study aims to apply the macroergonomic approach with health workers in order to propose and implement improvements; evidencing the importance of their involvement in better acceptance of the proposed improvements generating greater satisfaction. To this end, a study was conducted in the Billing sector of a Brazilian Hospital. Ergonomic demands were identified in a participatory way through the Macroergonomic Analysis of Work (MAW) method, proposed in [1]. The results were tabulated and divided into constructs: Environment, Biomechanical, Cognitive, Work Organization, Risk, Company and Discomfort/Pain. After one year, a new macroergonomic evaluation was carried out and the improvements implemented included the concept of the sociotechnical system, which were: i) acquisition of new computers; ii) implementation of a new computational system and; iii) implementation of changes in the form of sector management. The results showed an increase of up to 40% in satisfaction with the improvements implemented in the Biomechanical and Organizational constructs, indicating that the application of participatory ergonomics and macroergonomics was fundamental for the changes made to increase satisfaction in aspects of the work performed by them. Finally, this research highlights the importance of employee involvement in sociotechnical analysis for the humanization of organizations and it is suggested for future studies the proposition of improvements related to the Environment and Cognitive constructs and pain/discomforts.
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Gosman, James H., David A. Raichlen, and Timothy M. Ryan. "Human Transitions." In Children and Childhood in Bioarchaeology, 206–38. University Press of Florida, 2018. http://dx.doi.org/10.5744/florida/9780813056807.003.0007.

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The analysis of cortical and trabecular bone development morphology offers a lens through which general biological processes of skeletal ontogeny can be viewed. These, in turn, establish a foundation upon which biocultural reconstructions of childhood can proceed. In this chapter, the authors draw on skeletal data generated by their systematic cortical and trabecular bone research agenda from a Norris Farms’ archaeological skeletal collection using high resolution microCT imaging combined with new, age-segmented, gait data from extant children. The age-related changes in bone structure, geometry, and architecture are linked to the development of biomechanical competence over the course of three significant transitions in a human’s life course. This chapter identifies transitions and variations in human skeletal biology, skeletal morphology, and bipedal gait as dynamic records of development. These types of ontogenetic studies provide empirical data, which function as a portal to address fundamental issues of interest to anthropologists. Examples of the types of anthropological interests include, but are not limited to, reconstructing past health and behavior; understanding the dynamics of bone growth, size, and shape; interpreting skeletal variation; and providing insight into the fossil record.
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Ozemek, Cemal, Ross Arena, Dejana Popovic, Marco Guazzi, Amy McNeil, and Michael Sagner. "Cardiovascular response to exercise." In ESC CardioMed, edited by Guido Grassi, 139–43. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0026_update_001.

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The body’s response to an exertional stimulus, if performed adequately to meet the imposed demand, is an orchestrated response predominantly among the cardiovascular, pulmonary, and skeletal systems. These physiological systems work together to ensure that up-titrated energy and force production demands are met. The magnitude of the exertional stimulus these systems are able to respond to, when an individual is in a true state of physiological health, is influenced by multiple factors including age, sex, biomechanics, genomics, and exercise training history. When one or more of these systems suffers from dysfunction, as is the case when an individual is at risk for (i.e. unhealthy lifestyle history) or diagnosed with a chronic disease, the response to a physical stimulus ultimately fails and exertional capacity is limited. There is a clear and well-established clinical relevance to the cardiovascular response to an exertional stimulus, commonly assessed through a graded aerobic exercise test on a treadmill or cycle ergometer. In fact, aerobic capacity has been referred to a key vital sign. We are also gaining an appreciation of how communication and presentation of information between health professionals and individuals receiving care significantly impacts comprehension and adherence to a plan of care. This chapter addresses these areas, beginning with a brief granular description of exertional cardiovascular physiology, transitioning to practical clinical implications of this information for health professionals, and ending with how the individuals seeking healthcare receive, process, and comprehend this information with the ultimate goal being real-world application and improved health outcomes.
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Scano, Alessandro, Marco Caimmi, Andrea Chiavenna, Matteo Malosio, and Lorenzo Molinari Tosatti. "A Kinect-Based Biomechanical Assessment of Neurological Patients' Motor Performances for Domestic Rehabilitation." In Advances in Medical Technologies and Clinical Practice, 252–79. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9740-9.ch013.

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Stroke is one of the main causes of disability in Western countries. Damaged brain areas are not able to provide the fine-tuned muscular control typical of human upper-limbs, resulting in many symptoms that affect consistently patients' daily-life activities. Neurological rehabilitation is a multifactorial process that aims at partially restoring the functional properties of the impaired limbs, taking advantage of neuroplasticity, i.e. the capability of re-aggregating neural networks in order to repair and substitute the damaged neural circuits. Recently, many virtual reality-based, robotic and exoskeleton approaches have been developed to exploit neuroplasticity and help conventional therapies in clinic. The effectiveness of such methods is only partly demonstrated. Patients' performances and clinical courses are assessed via a variety of complex and expensive sensors and time-consuming techniques: motion capture systems, EMG, EEG, MRI, interaction forces with the devices, clinical scales. Evidences show that benefits are proportional to treatment duration and intensity. Clinics can provide intensive assistance just for a limited amount of time. Thus, in order to preserve the benefits and increase them in time, the rehabilitative process should be continued at home. Simplicity, easiness of use, affordability, reliability and capability of storing logs of the rehabilitative sessions are the most important requirements in developing devices to allow and facilitate domestic rehabilitation. Tracking systems are the primary sources of information to assess patients' motor performances. While expensive and sophisticated techniques can investigate neuroplasticity, neural activation (fMRI) and muscle stimulation patterns (EMG), the kinematic assessment is fundamental to provide basic but essential quantitative evaluations as range of motion, motor control quality and measurements of motion abilities. Microsoft Kinect and Kinect One are programmable and affordable tracking sensors enabling the measurement of the positions of human articular centers. They are widely used in rehabilitation, mainly for interacting with virtual environments and videogames, or training motor primitives and single joints. In this paper, the authors propose a novel use of the Kinect and Kinect One sensors in a medical protocol specifically developed to assess the motor control quality of neurologically impaired people. It is based on the evaluation of clinically meaningful synthetic performance indexes, derived from previously developed experiences in upper-limb robotic treatments. The protocol provides evaluations taking into account kinematics (articular clinical angles, velocities, accelerations), dynamics (shoulder torque and shoulder effort index), motor and postural control quantities (normalized jerk of the wrist, coefficient of periodicity, center of mass displacement). The Kinect-based platform performance evaluation was off-line compared with the measurements obtained with a marker-based motion tracking system during the execution of reaching tasks against gravity. Preliminary results based on the Kinect sensor suggest its efficacy in clustering healthy subjects and patients according to their motor performances, despite the less sensibility in respect to the marker-based system used for comparison. A software library to evaluate motor performances has been developed by the authors, implemented in different programming languages and is available for on-line use during training/evaluation sessions (Figure 1). The Kinect sensor coupled with the developed computational library is proposed as an assessment technology during domestic rehabilitation therapies with on-line feedback, enabled by an application featuring tracking, graphical representation and data logging. An experimental campaign is under development on post-stroke patients with the Kinect-One sensor. Preliminary results on patients with different residual functioning and level of impairment indicate the capability of the whole system in discriminating motor performances.
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Conference papers on the topic "Biomechanické limity"

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DeVries, Nicole A., Anup A. Gandhi, Douglas C. Fredericks, Joseph D. Smucker, and Nicole M. Grosland. "In Vitro Study of the C2-C7 Sheep Cervical Spine." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53167.

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Due to the limited availability of human cadaveric specimens, animal models are often utilized for in vitro studies of various spinal disorders and surgical techniques. Sheep spines have similar geometry, disc space, and lordosis as compared to humans [1,2]. Several studies have identified the geometrical similarities between the sheep and human spine; however these studies have been limited to quantifying the anatomic dimensions as opposed to the biomechanical responses [2–3]. Although anatomical similarities are important, biomechanical correspondence is imperative to understand the effects of disorders, surgical techniques, and implant designs. Some studies [3–5] have focused on experimental biomechanics of the sheep cervical functional spinal units (FSUs). Szotek and colleagues [1] studied the biomechanics of compression and impure flexion-extension for the C2-C7 intact sheep spine. However, to date, there is no comparison of the sheep spine using pure flexion-extension, lateral bending, or axial rotation moments for multilevel specimen. Therefore, the purpose of this study was to conduct in vitro testing of the intact C2-C7 sheep cervical spine.
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Maikos, Jason, Ragi Elias, Zhen Qian, Dimitris Metaxas, and David Shreiber. "In Vivo Tissue-Level Thresholds for Spinal Cord Injury." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176670.

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Traumatic loading conditions, such as those experienced during car accidents or falls, can lead to spinal cord injury (SCI), resulting in permanent functional damage [1]. A better understanding of the biomechanical causes of SCI and knowledge of the tolerance of spinal cord tissue to mechanical loading is critical in understanding how mechanisms of injury lead to neurologic deficits, as well as designing methods to prevent SCI. Finite element analysis (FEA) has become an important and cost effective tool to investigate the biomechanics of trauma. FEA has been used to study a variety of biomechanical analyses of trauma, including brain injury and spine injury biomechanics, but there have been limited analyses on spinal cord injury (SCI) [2–5]. In fact, despite the prevalence of small animal models in the neuroscience community used to study SCI, there have been no published analyses of in vivo models of SCI.
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Miller, Ross H., Brian R. Umberger, Joseph Hamill, and Graham E. Caldwell. "Dynamic Optimization of Maximum-Effort Human Sprinting." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-205781.

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Maximum speed is an important parameter for sprinting humans, particularly in athletic competitions. While the biomechanics of sprinting have been well-studied [1–3], our understanding of biomechanical limits to maximum speed is still in its infancy. Previous studies have suggested a speed-limiting role for the force-velocity relationship of skeletal muscle [2], but these theories are difficult to verify experimentally due to the difficulty in observing and manipulating human muscle dynamics in vivo.
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DeVries, Nicole A., Nicole A. Kallemeyn, Kiran H. Shivanna, and Nicole M. Grosland. "A Finite Element Analysis of the C2-C7 Sheep Spine." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19301.

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Due to the limited availability of human cadaveric specimens, sheep are often utilized for in vitro studies of various spinal disorders and surgical techniques. Understanding the similarities and differences between the human and sheep spine is crucial for constructing a valuable study and interpreting the results. Several studies have identified the anatomical similarities between the sheep and human spine; however these studies have been limited to quantifying the anatomic dimensions as opposed to the biomechanical responses [1–2]. Although anatomical similarities are important, biomechanical correspondence is imperative for studying the effects of disorders, surgical techniques, and implant designs. Studies by Wilke and colleagues [3] and Clarke et al. [4] have focused on experimental biomechanics of the sheep cervical functional spinal units (FSUs).
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Messner, Lukas, Hubert Gattringer, and Hartmut Bremer. "Generating Speed, Torque and Jerk Limited Trajectories along Specified Geometric Paths in Realtime." In Biomechanics / Robotics. Calgary,AB,Canada: ACTAPRESS, 2011. http://dx.doi.org/10.2316/p.2011.752-046.

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Messner, Lukas, Hubert Gattringer, and Hartmut Bremer. "Generating Speed, Torque and Jerk Limited Trajectories along Specified Geometric Paths in Realtime." In Biomechanics / Robotics. Calgary,AB,Canada: ACTAPRESS, 2012. http://dx.doi.org/10.2316/p.2012.752-046.

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Jun, Bong Jae, Joo Han Oh, Michelle H. McGarry, Akash Gupta, Kyung Chil Chung, James Hwang, and Thay Q. Lee. "Restoration of Shoulder Biomechanics in the Massive Rotator Cuff Tear According to Degree of Repair Completion." In ASME 2010 5th Frontiers in Biomedical Devices Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/biomed2010-32049.

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The development of new instruments and surgical techniques has improved the outcome of rotator cuff repair even with massive tears. Based on cuff integrity or amount of retraction with massive cuff tears a complete repair may not be possible allowing for only partial repair. The ability to mobilize the cuff to the footprint can affect the degree of partial repair that can be performed. Partial repair may lead to abnormal biomechanics that may predispose patients to limited function and subsequent pathology following rotator cuff repair. Therefore, the purpose of this study is to compare the biomechanical characteristics of massive rotator cuff repair according to the degree of repair completion and to determine a minimum degree of repair required to restore normal biomechanics.
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Cornejo, S. L., J. F. Rodriguez, A. A. Valencia, A. M. Guzman, and E. A. Finol. "Flow-Induced Wall Mechanics of Patient-Specific Aneurysmal Cerebral Arteries: Nonlinear Isotropic vs. Anisotropic Wall Stress." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-192626.

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There are several biomechanical factors involved in the formation, growth, remodeling, and eventual rupture of intracranial aneurysms. In particular, hemodynamic forces have a decisive role in the biomechanical environment of the aneurysmal cerebral vasculature. Most of the previous studies on vascular mechanics assessment of intracranial aneurysms are based on idealized geometries, where it has been suggested [1] that it is highly unlikely that saccular aneurysms expand due to a limit point instability. In addition, it has been reported [2] that some saccular aneurysms with non-spherical initial shape tend to become spherical when subjected to uniform pressure, because a spherical geometry is optimal to resist the pressure load, yielding a homogenous wall stress. In the present work, we present a comparison between anisotropic and isotropic constitutive models, which allows us to analyze the biomechanics of patient-specific cerebral aneurysmal arteries subjected to flow-induced pulsatile pressure. The results describe the effects of material anisotropy in the resulting wall mechanics of the intracranial vasculature geometries.
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Careme, L. M. M. "Biomechanical Tolerance Limits of the Cranio-Cervical Junction in Side Impacts." In SAE International Congress and Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1989. http://dx.doi.org/10.4271/890383.

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Schofield, Jonathon S., Samer M. Adeeb, and Eric C. Parent. "An Assistive Knee-Ankle-Foot-Orthosis and Sit-to-Stand Biomechanics." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80268.

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Knee-Ankle-Foot-Orthoses (KAFOs) are leg braces designed to assist in standing for patients with limited lower extremity function. The brace holds the knee extended and the ankle in a neutral position, thereby controlling balance and joint alignment. KAFOs have a variety of applications from skeletal complications to muscular weakness and paralysis (1). Patients experiencing such conditions are often dependant on the use of a wheelchair. Standing, therefore, becomes an important physiological function with benefits including pressures relief, spasticity reduction, bowel-and-bladder management, among others (2). However, since a KAFO limits knee and ankle motion, rising from a chair becomes a significant challenge as it requires substantial upper body strength to hoist oneself from seated position. Consequently, many KAFO users are unable to achieve sit-to-stand (STS) independently.
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