Este trabalho apresentará um projeto cujo propósito foi definir um protocolo de avaliação para pacientes paraplégicos sob terapia, através do uso de estimulação elétrica neuromuscular, no ambulatório de ortopedia do Hospital das Clínicas da Universidade de Campinas. A análise proposta servirá tanto para o acompanhamento da evolução dos pacientes, quanto, principalmente, para avaliação dos sistemas de reabilitação desenvolvidos pelo laboratório de biocibernética e engenharia de reabilitação na Escola de Engenharia de São Carlos. Neste trabalho o protocolo foi aplicado especificamente para descrever a locomoção do paraplégico usando a estimulação padrão de 4 canais, que realiza a ativação dos quadríceps para extensão das pernas, necessária para o suporte do corpo, e a ativação do reflexo de retirada através da estimulação do nervo fibular para a flexão necessária para a fase de balanço. A análise usou como referência o conhecimento relacionado à descrição das fases e estratégias usadas pela locomoção do ser humano intacto. O protocolo de avaliação usou recursos do laboratório de biomecânica e reabilitação do aparelho locomotor, situado no hospital citado acima, que permitiram a descrição da cinemática dos membros superiores e inferiores, da atividade muscular realizada pelos membros superiores, e das forças de reação do solo. / This work present a case study on the use of the motion analysis laboratory resources (three-dimensional motion capture system, EMG, and force plate) with the purpose of improve the use of surface electrical stimulation to enable the locomotion in paraplegic subjects. Five trials for each of the five patients (thoracic complete spinal cord lesion) using a four channel electrical stimulator was done for synchronously acquisition of: 3D coordinates of 30 markers distributed on the whole body (to evaluate the stride\'s characteristics and three-dimensional measurements of angles of whole-body); EMG signal, on both sides, of triceps brachii long head, pectoralis major, middle deltoideus, extensor carpi radialis; and the vertical component of the ground reaction force. All data were normalized on the right gait cycle. The analysis was done braking the cycle in 11 events related with the swing phase in both sides, because it was focused firstly in the actions related with the swing limb and upper body advance, that represents a critical factor in locomotion aided by electrical stimulation. These events divided the gait cycle in 10 phases, which was used for associate the data evaluated with specifics tasks. The results showed temporal parameters similar to that reported by other authors, specific characteristics of the patient, the mechanism used by the patient for advance the body, and the periods of high activity of the muscles on the cycle.

Orientador: Claudio Alexandre Gobatto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-25T15:01:29Z (GMT). No. of bitstreams: 1 Scariot_PedroPauloMenezes_M.pdf: 1584888 bytes, checksum: 8356b3aa4fe31d35fcd7190b3ef7cbb2 (MD5) Previous issue date: 2014 / Resumo: A locomoção representa um comportamento extremamente importante e primordial para a vida animal. Diante disso, torna-se notório que o restrito confinamento imposto aos animais de laboratório pode causar negativas implicações fisiológicas, uma vez que diversos comportamentos locomotores naturais são suprimidos. Baseado nessa problemática, desejamos verificar se animais alojados em gaiolas convencionais possuem piores indicadores de desempenho ao exercício, quando comparados a animais expostos a condições aumentadas de espaço físico. Além disso, buscamos analisar se a característica do espaço físico das gaiolas representa um fator mais relevante que a própria aplicação do exercício, haja vista que protocolos de treinamento físico em modelos animais não conseguem promover melhoras expressivas da capacidade aeróbia ao longo da idade. Em outra temática, a locomoção também se apresenta intimamente relacionada a aspectos genéticos, uma vez que marcantes diferenças individuais são distinguidas quando rodas de atividades são disponibilizadas para animais de laboratório. Entendendo que o aspecto genético é de suma importância nesse contexto, nós supomos que animais mais ativos na gaiola, exibiriam maiores vantagens metabólicas e genéticas para a prática de exercício quando comparados a animais mais inativos. Diante disso, buscamos explorar se as atividades espontâneas e voluntárias dos animais já refletem propensões para melhores desempenhos físicos. Embora pareçam similares, tais atividades são consideradas distintas pela literatura, e carecem de serem relacionadas com a capacidade aeróbia, e com respostas moleculares envolvidas com a performance. Tendo em vista todos os temas abordados, o objetivo geral do presente projeto baseia-se em verificar a influência do espaço físico da gaiola, bem como sua interação com as duas principais intervenções experimentais científicas (treinamento físico ou livre acesso à roda de atividade) sobre respostas fisiológicas e moleculares relacionadas com o metabolismo aeróbio e anaeróbio, composição corporal e estresse em ratos ao longo da idade (60, 90 e 150 dias). Além disso, verificar as relações entre a atividade espontânea e voluntária com parâmetros fisiológicos envolvidos com a performance no exercício / Abstract: Locomotion is extremely important and essential for animal life behavior. Thus, it becomes clear that the restricted confinement and therefore the suppression of many locomotors behaviors imposed to laboratory animals can cause negative physiological implications. Based on these problems, we verified if animals housed in conventional cages have worse exercise performance indicators when compared to animals exposed in increased housing space. Furthermore, we analyzed if the physical space of the cages is a more important factor than implementation of the exercise, given that physical training protocols in animal models fail to promote improvements in aerobic capacity over the age. On another topic, locomotion is closely related to genetic factors. We assumed that animals more active in the cage, exhibit higher metabolic and genetic advantages for the practice of exercise when compared to inactive animals. Therefore, we investigated whether the spontaneous and voluntary activities of animals already reflect propensities for better physical performance. Although they look similar, these activities are considered distinct in the literature. There is scarce information about the relationship of such with aerobic capacity and molecular responses involved with the performance. The overall goal of this project is based on checking the influence of the housing space of the cage as well as its interaction with the two main scientific experimental interventions (physical training or free access to activity wheel) on physiological and molecular responses related aerobic and anaerobic metabolism, body composition and stress in rats along age. In addition, to check the relationship between spontaneous and voluntary activity with physiological parameters involved with the exercise performance / Mestrado / Biodinâmica do Movimento Humano e Esporte / Mestre em Ciências da Nutrição e do Esporte e Metabolismo

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OBJECTIVES: Comparing electromyography and physiological measures while walking on various inclines in unstable and stable shoes. METHODS: Eleven healthy females walked on treadmill at +10%, 0% and -10% grade for five minutes each, at self-selected pace, in stable and unstable shoes. The two sessions were done 3weeks apart during which the subjects used unstable shoes for regular activities. Electromyography of lower limb muscles, absolute and relative oxygen consumption, perceived exertion rating and heart rate was calculated. RESULTS: Tibialis anterior activation varied significantly with shoe type, irrespective of grade. Soleus, vastus medialis, and biceps femoris showed activation differences in specific gait phases. There was a main effect for absolute and relative oxygen consumption, RPE and HR only with grade. Shoe type showed no effect. CONCLUSION: Though there is no difference in overall physiological variables, but changes in electromyography in specific phases highlight possible muscle toning benefits of unstable shoes. / Graduate / 0350 / 0354 / 0382 / avneetchatha@gmail.com

Master of Science / Department of Animal Sciences and Industry / Lindsey E. Hulbert / Stressors and stress responses are part of everyday life, for both humans and animals. Organisms evolved well-developed mechanisms to cope with most stressors, and to recover from stress responses. Nevertheless, severe acute stressors and chronic stressors lead to health problems. Traumatic brain injury (TBI) is defined as malfunctioning and pathology of the brain caused by external mechanical forces. This physical and psychological stressor may lead to long-term damage on both physiology and psychology mechanisms. Traumatic brain injury becomes a public health issue for millions of soldiers, veterans and general public, who suffer from its aftermath and reduced quality of life. To understand TBI, human patients and rodents models were extensively studied. In recent years, miniswine were utilized to research the histopathology of TBI. They serve as a better human brain model because their nervous system is more anatomically relevant than rodents, their brains have similar white:grey matter ratios as humans, and they have similar cognitive abilities as humans. Despite the progresses in pathology and histology work among miniswine models of TBI, there were not validated behavior tests for this new animal model. This thesis introduced two behavior-tests for Yucatan miniboar models. The first study was conducted to validate a modified human approach test (HAT) specifically designed for Yucatan miniboars for mild TBI experiments. This test was originally validated and widely used for commercial pigs. The current test was designed around the housing and animal care, with the experimental performing the test outside of pens where pigs were individually housed. Animals were treated with a single blast wave (BLAST) or anesthesia only (control, SHAM), and were tested 3 days before the treatment (baseline) and 3 consecutive days after the treatment. During the test, the spatial positions (Climb, Close, Mid and Far) and structural positions (Stand, Lie) were measured. Climb and Close were collectively named approach behaviors, and Mid and Far Move away behaviors. Results showed that this test had high reliability, and was sensitive to acute effects of TBI: BLAST-treated pigs showed decreased approach behaviors and increased move away behaviors following the treatment, compared to the baseline. The second experiment was conducted to develop automated data collection methods to monitor circadian active and inactive behaviors of miniboars. Using the same experimental design as described previously, Fitbit Zip, a commercially available accelerometer with an embedded algorithm (Fitbit, San Francisco, CA), was tested. When attached to ear tags, Fitbit Zip was validated to be recording head movements without locomotion, which were oral-nasal-facial (ONF) behaviors. Results showed that Fitbit Zips best-detected behavior changes following TBI at 2-hour observation intervals. BLAST animals showed decreased ONF behaviors during the day especially around the feeding time, which were also when the pigs were most active. Both behavior-tests were shown to be reliable and useful in measuring behavior changes following TBI in Yucatan miniboar models. Measures of behavior were shown to be a promising and valuable addition to the biomedical research utilizing large animal models. These advances in knowledge and technology could also benefit farm animal production.

One of the most striking things about many animals is that they can be defined by the ways in which they move. Moving costs metabolic energy and is a significant contributor to the daily energy balance of organisms and therefore fitness. Balancing energy needs is critically important to species inhabiting areas of limited resources. The metabolic cost of locomotion is influenced by physiological, morphological and behavioural factors that vary across species. The influence of these factors within species is less well understood. The objective of my PhD is to elucidate the potential for variation in locomotor performance, in particular the energy consumed and the biomechanics of locomotion within a species, in response to differences in season, sex, age and the nature of the terrain. The Svalbard ptarmigan (Lagopus muta hyperborea) is the only year-round avian resident of the Arctic archipelago of Svalbard. Svalbard is characterized by extreme photoperiodic and climatic conditions, with 24 hours of daylight in summer and continuous darkness in winter, when ice makes food unpredictable. As a result, ptarmigan annually gain significant fat stores, as much as doubling their body mass in winter. The consequences of such large gains in mass upon the metabolic cost and biomechanics of terrestrial locomotion are yet to be quantified. The Svalbard ptarmigan represents a unique opportunity to gain insight into avian adaptations.Using respirometry, I present evidence that winter birds are able to carry their fat stores at no metabolic cost. Using kinematic and force plate data, I show that acquiring fat results in reduced locomotor performance in terms of speed and take-off ability. As well as exhibiting phenotypic variation, male and female Svalbard ptarmigan are behaviourally very different. I present evidence that these behavioural differences are reflected in the metabolic cost of locomotion. In particular, males are both more efficient and faster than female birds during both summer and winter. I suggest that this results from sexual selection upon male locomotor performance. Furthermore, I present data demonstrating that sub-adult males experiencing their first winter possess the same metabolic and speed capabilities of adults. These data may indicate that selection for improved male locomotor performance may act upon sub-adult birds. Regardless of season, age or sex, Svalbard ptarmigan must locomote on a predominantly sloping terrain. The influence of inclines upon the metabolic cost of locomotion in birds is poorly understood. I provide evidence that at the same degree of incline, the cost of lifting 1 kg by 1 vertical metre is similar regardless of season and is therefore dictated by increased positive work. However, this cost varies according to the degree of incline and may be influenced by gait.The principal findings of the 5 first author papers presented are that behavioural, physiological and morphological variation within a species can have significant impacts upon the metabolic cost of locomotion and other aspects of locomotor performance. The potential for intraspecific differences should therefore be taken into account in future research regarding the patterns of energy expenditure in animals.

Legged locomotion has several interesting challenges that need to be addressed, such as the ability of dynamically walk over rough terrain like stairs or stepping stones, as well as the ability to adapt to unexpected changes in the environment and the dynamic model of the robot. This thesis is driven towards solving these challenges and makes contributions on theoretical and experimental aspects to address: dynamic walking, model uncertainty, and rough terrain. On the theoretical front, we introduce and develop a unified robust and adaptive control framework that enables the ability to enforce stability and safety-critical constraints arising from robotic motion tasks under a high level of model uncertainty. We also present a novel method of walking gait optimization and gait library to address the challenge of dynamic robotic walking over stochastically generated stepping stones with significant variations in step length and step height, and where the robot has knowledge about the location of the next discrete foothold only one step ahead. On the experimental front, our proposed methods are successfully validated on ATRIAS, an underactuated, human-scale bipedal robot. In particular, experimental demonstrations illustrate our controller being able to dynamically walk at 0.6 m/s over terrain with step length variation of 23 to 78 cm, as well as simultaneous variation in step length and step height of 35 to 60cm and -22 to 22cm respectively. In addition to that, we also successfully implemented our proposed adaptive controller on the robot, which enables the ability to carry an unknown load up to 68 lb (31 kg) while maintaining very small tracking errors of about 0.01 deg (0.0017 rad) at all joints. To be more specific, we firstly develop robust control Lyapunov function based quadratic program (CLFQP) controller and L1 adaptive control to handle model uncertainty for bipedal robots. An application is dynamic walking while carrying an unknown load. The robust CLF-QP controller can guarantee robustness via a quadratic program that can be extended further to achieve robust safety-critical control. The L1 adaptive control can estimate and adapt to the presence of model uncertainty in the system dynamics. We then present a novel methodology to achieve dynamic walking for underactuated and hybrid dynamcal bipedal robots subject to safety-critical constraints. The proposed controller is based on the combination of control Barrier functions (CBFs) and control Lyapunov functions (CLFs) implemented as a state-based online quadratic program to achieve stability under input and state constraints. The main contribution of this work is the control design to enable stable dynamical bipedal walking subject to strict safety constraints that arise due to walking over a terrain with randomly generated discrete footholds. We next introduce Exponential Control Barrier Functions (ECBFs) as means to enforce high relativedegree safety constraints for nonlinear systems. We also develop a systematic design method that enables creating the Exponential CBFs for nonlinear systems making use of tools from linear control theory. Our method creates a smooth boundary for the safety set via an exponential function, therefore is called Exponential CBFs. Similar to exponential stability and linear control, the exponential boundary of our proposed method helps to have smoother control inputs and guarantee the robustness under model uncertainty. The proposed control design is numerically validated on a relative degree 4 nonlinear system (the two-link pendulum with elastic actuators and experimentally validated on a relative degree 6 linear system (the serial cart-spring system). Thanks to these advantages of Exponential CBFs, we then can apply the method to the problem of 3D dynamic walking with varied step length and step width as well as dynamic walking on time-varying stepping stones. For the work of using CBF for stepping stones, we use only one nominal walking gait. Therefore the range of step length variation is limited ([25 : 60](cm)). In order to improve the performance, we incorporate CBF with gait library and increase the step length range significantly ([10 : 100](cm)). While handling physical constraints and step transition via CBFs appears to work well, these constraints often become active at step switching. In order to resolve this issue, we introduce the approach of 2-step periodic walking. This method not only gives better step transitions but also offers a solution for the problem of changing both step length and step height. Experimental validation on the real robot was also successful for the problem of dynamic walking on stepping stones with step lengths varied within [23 : 78](cm) and average walking speed of 0:6(m=s). In order to address the problems of robust control and safety-critical control in a unified control framework, we present a novel method of optimal robust control through a quadratic program that offers tracking stability while subject to input and state-based constraints as well as safety-critical constraints for nonlinear dynamical robotic systems under significant model uncertainty. The proposed method formulates robust control Lyapunov and barrier functions to provide guarantees of stability and safety in the presence of model uncertainty. We evaluate our proposed control design on different applications ranging from a single-link pendulum to dynamic walking of bipedal robot subject to contact force constraints as well as safety-critical precise foot placements on stepping stones, all while subject to significant model uncertainty. We conduct preliminary experimental validation of the proposed controller on a rectilinear spring-cart system under different types of model uncertainty and perturbations. To solve this problem, we also present another solution of adaptive CBF-CLF controller, that enables the ability to adapt to the effect of model uncertainty to maintain both stability and safety. In comparison with the robust CBF-CLF controller, this method not only can handle a higher level of model uncertainty but is also less aggressive if there is no model uncertainty presented in the system.

Navigating to a previously seen target without vision was unaffected by a 30-sec delay period at the beginning of the walking task. This study investigated whether a 60-sec delay, with or without a cognitive task, would modify the accuracy of reaching an 8-meter target. Thirty young adults participated. The delay, located at 0, 4, or 7 meters, was either to wait, or to count backwards. Kinematic data of distance travelled, distance-to-target, angular deviation, and body rotation from participants’ final position were recorded with a 3-D motion analysis system. Navigation precision was not significantly different with or without a delay, and whether or not the delays contained a cognitive task. However, comparisons among delays revealed a significant effect of delay position with larger distance errors occurring at the 0-meter delay in the 16 participants who walked at least 7 meters, suggesting that a delay at the beginning was more disruptive for navigation accuracy than when it occurred closer to the target.

The stopping of an earlier intended action is best explained in a race between a go process and a stop process (Logan & Cowan, 1984). The finish line, to which each process races, has been likened to a point of no return, specifically one that marks the onset of a final ballistic (unstoppable) process. Of note is the typical relation of reduced go probabilities and faster go latencies at shorter signal onset asynchronies (SOAs). (The SOA is the time interval between presentation of the go signal and presentation of the stop signal.) We report, in some cases, sub-maximal surface electromyograms (EMGs) at onset when trying to stop a maximal speeded action. These data indicate reduced synaptic drive to reach the motor pools as a result of earlier stopping effects and, as such, hold important implications for a theory of control. First, we interpret these data to suggest that the point of no return is phantom. Sub-maximal EMGs indicate a point in the control stream beyond which some EMG will be later observed but, importantly, they fail to mark the onset of a final ballistic process if, once breached, the same process remains subject to further effects of stopping. The alternative interpretation, however, that of a final ballistic process that receives sub-maximal input which results in sub-maximal output (i.e., EMG onset) cannot be ruled out from these data. We used the Hoffmann (H) reflex to probe further the mechanism of control for stopping a voluntary action. The H-reflex, an involuntary reflex that is taken as an index of spinal control, is relevant to the control of stopping because it is typically facilitated a short time before EMG onset. In other words, it provides a window of control within which a final ballistic process would otherwise be expected to locate. Thus, we interpret the effects of stopping on the H-reflex before EMG onset as strong evidence against a final ballistic process. Second, while the race model can explain the relation between the go probabilities, the go latencies and the SOAs, it fails to explain the sub-maximal EMG onsets that describe that same action in some cases. We submit a mechanism of excitatory-inhibitory interaction at all times up to the motor pool to explain both sets of empirical data. The viability of this theory is demonstrated using computer analyses. / Education, Faculty of / Kinesiology, School of / Graduate