Wheelchair manufacturers design their products to provide the best possible experience to their users. The user effort and wheelchair mechanical efficiency during motion are highly affected by rolling resistance, which is a resistive force depending on many factors such as vehicle speed, tire/floor materials and tire inflation pressure. The study of this force over several conditions could lead to improvements in wheelchair design. The Anatomical Model Propulsion System (AMPS) is a robotic device to test manual wheelchairs with better repeatability than human subjects, helping to identify the effect of resistive forces. It uses electric motors to apply torque directly to the rear wheel handrims. In this thesis, a control system is developed to achieve a specified wheelchair trajectory and velocity profile, by controlling the input torque to the system. A kinetic and dynamic model is used to estimate this necessary input. Data collected from different experiments allows to determine rolling resistance under various conditions. The results show that rolling resistance also varies with acceleration, affecting the overall mechanical efficiency of a wheelchair following different velocity profiles.

The aim of the Master's thesis is to compare and quantify the impact of the introduction of electronic toll collection system at the costs of the carrier's export transport of Prešov (SK) - Werlte (DE). Attention is devoted to a detailed analysis of the cost of toll truck emission standards Euro II, Euro III and Euro V. Analysis of the toll costs consists of quantifying the unit costs per kilometer, the total annual costs and transport costs in the period of the years 2003 and 2010.

O objetivo do presente estudo foi comparar o comportamento dos parâmetros mecânicos (Wext, Wint, Wtot, CP, FP), parâmetros energéticos (Pmet, C, Eff, Vótima) e do mecanismo pendular (R, Rint, %Cong) durante a caminhada com carga no plano (0%), nas inclinações (+7% e +15%) e em distintas velocidades de caminhada. A amostra foi composta por 10 homens jovens, saudáveis, fisicamente ativos e não adaptados ao transporte de carga em mochilas. Os sujeitos caminharam em uma esteira rolante durante 5 min, em cinco diferentes velocidades, sem e com carga (25% da MC) transportada em mochilas, e em três planos distintos de caminhada (0%, 7% e 15%). A análise de movimento 3D (quatro câmeras de vídeo) foi realizada simultaneamente à análise de VO2. Realizaram-se rotinas computacionais para o processamento de dados cinemáticos em Matlab®. Utilizou-se ANOVA de 3 fatores para medidas repetidas, com post hoc de Bonferroni (p < 0,05; SPSS 17.0). Os resultados dos parâmetros mecânicos indicam modificações devido à velocidade e ao plano de caminhada; a carga não modificou algumas das variáveis. Todas as variáveis mecânicas aumentaram com o incremento da velocidade, o Wint e a FP diminuíram a 7% e logo aumentaram a 15%, o Wext e Wtot aumentaram com a inclinação, e o CP diminuiu com o aumento da inclinação. A carga não afetou na maioria das situações o Wext e o Wtot, demonstrando que os parâmetros mecânicos são de modo geral, independentes da carga tanto no plano como nas inclinações. As variáveis energéticas da caminhada foram influenciadas pela velocidade, inclinação e a carga. A Pmet aumentou com o incremento da velocidade, da inclinação e da carga. O C diminuiu com o incremento da velocidade e logo aumentou, atingindo um mínimo nas velocidades intermediárias e, também aumentou com o incremento da inclinação e da carga. A Eff aumentou com a velocidade, diminuiu com o aumento da inclinação e a carga. A Vótima de caminhada foi reduzida com o incremento da inclinação. Constatou-se que o mecanismo pendular é modificado principalmente como decorrência da velocidade e da inclinação do terreno, e é independente da carga. O R e o Rint aumentam com o acréscimo da velocidade de caminhada, logo diminuem com o incremento da inclinação e ambos são independentes da carga. Conclui-se que as diferentes restrições impostas através da variação da carga e inclinações provocaram adaptações na mecânica e energética da locomoção humana, sustentando a Vótima e a reconversão das energias mecânicas (R) nas inclinações. Deste modo, ainda que em menor proporção, a estratégia de minimização de energia por via pendular ainda persiste nestas condições. / The purpose of the present study was to compare the behavior of the mechanical parameters (Wext, Wint, Wtot, SF, SL), the energetic parameters (Metabolic Power, C, Eff, optimal speed) and the pendular mechanism (R, Rint, %congruity) during walking with load on level (0%) and gradients (7% and 15%) and at different walking speeds. Ten young men, healthy, physically active and not adapted to walking loaded in backpacks participated in the study. The subjects walked in a treadmill for five minutes, under five different speeds, without and with load (25% of bM) carried in backpacks and in three different gradients of walking (0%, 7% e 15%). The analysis of the 3D movement was registered (four video cameras), as well as the VO2 analysis. Computational routines for the processing of kinematic data were done in Matlab®. The results were analyzed using repeated measures ANOVA (factors: speed, gradients, load) with the Bonferroni correction for post-hoc comparisons (p < 0.05) (SPSS 17.0). The results of the mechanical parameters indicate modifications due to speed and gradients of the walking; the load did not modify some of the variables. All of the mechanical variables increased with the raise in speed, the Wint and the SF decreased at 7% and right away increased at 15%, the Wext and Wtot increased with the gradient, and the SL decreased with the raising gradient. The load did not affect most of the situations, the Wext and Wtot, decreasing with the loaded situation, showing that the mechanical parameters are, in general, independent of the load on level and gradients. The energetic parameters of the walking were influenced by the speed, the gradient and the load. The metabolic power increased with the raise in speed, in gradient and in load. The cost of transport decreased with raise in speed and increased right away, influencing the minimum cost at intermediate speeds and it also increased with the raise of the slope and the load. The efficiency increased with speed and decreased with the raise of gradient and load. The optimal speed of walking was reduced with increasing of gradient. It was verified that the pendular mechanism is mainly modified as a consequence of speed and the gradient, and is independent of load. The R and Rint increase with the raise of speed, and decrease with the raise of gradient, also there are independent of the load. The conclusion is that the different restrictions imposed through the load variation and gradients cause adaptations in the mechanics and energetic of the human locomotion, sustaining the optimal speed and reconversion of the mechanical energies in gradients. In this way, but in a smaller proportion, the strategy of minimizing the energy through the pendular mechanism still persists in these conditions.

O objetivo do presente estudo foi comparar o comportamento dos parâmetros mecânicos (Wext, Wint, Wtot, CP, FP), parâmetros energéticos (Pmet, C, Eff, Vótima) e do mecanismo pendular (R, Rint, %Cong) durante a caminhada com carga no plano (0%), nas inclinações (+7% e +15%) e em distintas velocidades de caminhada. A amostra foi composta por 10 homens jovens, saudáveis, fisicamente ativos e não adaptados ao transporte de carga em mochilas. Os sujeitos caminharam em uma esteira rolante durante 5 min, em cinco diferentes velocidades, sem e com carga (25% da MC) transportada em mochilas, e em três planos distintos de caminhada (0%, 7% e 15%). A análise de movimento 3D (quatro câmeras de vídeo) foi realizada simultaneamente à análise de VO2. Realizaram-se rotinas computacionais para o processamento de dados cinemáticos em Matlab®. Utilizou-se ANOVA de 3 fatores para medidas repetidas, com post hoc de Bonferroni (p < 0,05; SPSS 17.0). Os resultados dos parâmetros mecânicos indicam modificações devido à velocidade e ao plano de caminhada; a carga não modificou algumas das variáveis. Todas as variáveis mecânicas aumentaram com o incremento da velocidade, o Wint e a FP diminuíram a 7% e logo aumentaram a 15%, o Wext e Wtot aumentaram com a inclinação, e o CP diminuiu com o aumento da inclinação. A carga não afetou na maioria das situações o Wext e o Wtot, demonstrando que os parâmetros mecânicos são de modo geral, independentes da carga tanto no plano como nas inclinações. As variáveis energéticas da caminhada foram influenciadas pela velocidade, inclinação e a carga. A Pmet aumentou com o incremento da velocidade, da inclinação e da carga. O C diminuiu com o incremento da velocidade e logo aumentou, atingindo um mínimo nas velocidades intermediárias e, também aumentou com o incremento da inclinação e da carga. A Eff aumentou com a velocidade, diminuiu com o aumento da inclinação e a carga. A Vótima de caminhada foi reduzida com o incremento da inclinação. Constatou-se que o mecanismo pendular é modificado principalmente como decorrência da velocidade e da inclinação do terreno, e é independente da carga. O R e o Rint aumentam com o acréscimo da velocidade de caminhada, logo diminuem com o incremento da inclinação e ambos são independentes da carga. Conclui-se que as diferentes restrições impostas através da variação da carga e inclinações provocaram adaptações na mecânica e energética da locomoção humana, sustentando a Vótima e a reconversão das energias mecânicas (R) nas inclinações. Deste modo, ainda que em menor proporção, a estratégia de minimização de energia por via pendular ainda persiste nestas condições. / The purpose of the present study was to compare the behavior of the mechanical parameters (Wext, Wint, Wtot, SF, SL), the energetic parameters (Metabolic Power, C, Eff, optimal speed) and the pendular mechanism (R, Rint, %congruity) during walking with load on level (0%) and gradients (7% and 15%) and at different walking speeds. Ten young men, healthy, physically active and not adapted to walking loaded in backpacks participated in the study. The subjects walked in a treadmill for five minutes, under five different speeds, without and with load (25% of bM) carried in backpacks and in three different gradients of walking (0%, 7% e 15%). The analysis of the 3D movement was registered (four video cameras), as well as the VO2 analysis. Computational routines for the processing of kinematic data were done in Matlab®. The results were analyzed using repeated measures ANOVA (factors: speed, gradients, load) with the Bonferroni correction for post-hoc comparisons (p < 0.05) (SPSS 17.0). The results of the mechanical parameters indicate modifications due to speed and gradients of the walking; the load did not modify some of the variables. All of the mechanical variables increased with the raise in speed, the Wint and the SF decreased at 7% and right away increased at 15%, the Wext and Wtot increased with the gradient, and the SL decreased with the raising gradient. The load did not affect most of the situations, the Wext and Wtot, decreasing with the loaded situation, showing that the mechanical parameters are, in general, independent of the load on level and gradients. The energetic parameters of the walking were influenced by the speed, the gradient and the load. The metabolic power increased with the raise in speed, in gradient and in load. The cost of transport decreased with raise in speed and increased right away, influencing the minimum cost at intermediate speeds and it also increased with the raise of the slope and the load. The efficiency increased with speed and decreased with the raise of gradient and load. The optimal speed of walking was reduced with increasing of gradient. It was verified that the pendular mechanism is mainly modified as a consequence of speed and the gradient, and is independent of load. The R and Rint increase with the raise of speed, and decrease with the raise of gradient, also there are independent of the load. The conclusion is that the different restrictions imposed through the load variation and gradients cause adaptations in the mechanics and energetic of the human locomotion, sustaining the optimal speed and reconversion of the mechanical energies in gradients. In this way, but in a smaller proportion, the strategy of minimizing the energy through the pendular mechanism still persists in these conditions.

O objetivo do presente estudo foi comparar o comportamento dos parâmetros mecânicos (Wext, Wint, Wtot, CP, FP), parâmetros energéticos (Pmet, C, Eff, Vótima) e do mecanismo pendular (R, Rint, %Cong) durante a caminhada com carga no plano (0%), nas inclinações (+7% e +15%) e em distintas velocidades de caminhada. A amostra foi composta por 10 homens jovens, saudáveis, fisicamente ativos e não adaptados ao transporte de carga em mochilas. Os sujeitos caminharam em uma esteira rolante durante 5 min, em cinco diferentes velocidades, sem e com carga (25% da MC) transportada em mochilas, e em três planos distintos de caminhada (0%, 7% e 15%). A análise de movimento 3D (quatro câmeras de vídeo) foi realizada simultaneamente à análise de VO2. Realizaram-se rotinas computacionais para o processamento de dados cinemáticos em Matlab®. Utilizou-se ANOVA de 3 fatores para medidas repetidas, com post hoc de Bonferroni (p < 0,05; SPSS 17.0). Os resultados dos parâmetros mecânicos indicam modificações devido à velocidade e ao plano de caminhada; a carga não modificou algumas das variáveis. Todas as variáveis mecânicas aumentaram com o incremento da velocidade, o Wint e a FP diminuíram a 7% e logo aumentaram a 15%, o Wext e Wtot aumentaram com a inclinação, e o CP diminuiu com o aumento da inclinação. A carga não afetou na maioria das situações o Wext e o Wtot, demonstrando que os parâmetros mecânicos são de modo geral, independentes da carga tanto no plano como nas inclinações. As variáveis energéticas da caminhada foram influenciadas pela velocidade, inclinação e a carga. A Pmet aumentou com o incremento da velocidade, da inclinação e da carga. O C diminuiu com o incremento da velocidade e logo aumentou, atingindo um mínimo nas velocidades intermediárias e, também aumentou com o incremento da inclinação e da carga. A Eff aumentou com a velocidade, diminuiu com o aumento da inclinação e a carga. A Vótima de caminhada foi reduzida com o incremento da inclinação. Constatou-se que o mecanismo pendular é modificado principalmente como decorrência da velocidade e da inclinação do terreno, e é independente da carga. O R e o Rint aumentam com o acréscimo da velocidade de caminhada, logo diminuem com o incremento da inclinação e ambos são independentes da carga. Conclui-se que as diferentes restrições impostas através da variação da carga e inclinações provocaram adaptações na mecânica e energética da locomoção humana, sustentando a Vótima e a reconversão das energias mecânicas (R) nas inclinações. Deste modo, ainda que em menor proporção, a estratégia de minimização de energia por via pendular ainda persiste nestas condições. / The purpose of the present study was to compare the behavior of the mechanical parameters (Wext, Wint, Wtot, SF, SL), the energetic parameters (Metabolic Power, C, Eff, optimal speed) and the pendular mechanism (R, Rint, %congruity) during walking with load on level (0%) and gradients (7% and 15%) and at different walking speeds. Ten young men, healthy, physically active and not adapted to walking loaded in backpacks participated in the study. The subjects walked in a treadmill for five minutes, under five different speeds, without and with load (25% of bM) carried in backpacks and in three different gradients of walking (0%, 7% e 15%). The analysis of the 3D movement was registered (four video cameras), as well as the VO2 analysis. Computational routines for the processing of kinematic data were done in Matlab®. The results were analyzed using repeated measures ANOVA (factors: speed, gradients, load) with the Bonferroni correction for post-hoc comparisons (p < 0.05) (SPSS 17.0). The results of the mechanical parameters indicate modifications due to speed and gradients of the walking; the load did not modify some of the variables. All of the mechanical variables increased with the raise in speed, the Wint and the SF decreased at 7% and right away increased at 15%, the Wext and Wtot increased with the gradient, and the SL decreased with the raising gradient. The load did not affect most of the situations, the Wext and Wtot, decreasing with the loaded situation, showing that the mechanical parameters are, in general, independent of the load on level and gradients. The energetic parameters of the walking were influenced by the speed, the gradient and the load. The metabolic power increased with the raise in speed, in gradient and in load. The cost of transport decreased with raise in speed and increased right away, influencing the minimum cost at intermediate speeds and it also increased with the raise of the slope and the load. The efficiency increased with speed and decreased with the raise of gradient and load. The optimal speed of walking was reduced with increasing of gradient. It was verified that the pendular mechanism is mainly modified as a consequence of speed and the gradient, and is independent of load. The R and Rint increase with the raise of speed, and decrease with the raise of gradient, also there are independent of the load. The conclusion is that the different restrictions imposed through the load variation and gradients cause adaptations in the mechanics and energetic of the human locomotion, sustaining the optimal speed and reconversion of the mechanical energies in gradients. In this way, but in a smaller proportion, the strategy of minimizing the energy through the pendular mechanism still persists in these conditions.

A caminhada humana é um movimento importante utilizado pelo homem, porém extremamente complexo em relação aos mecanismos energéticos e mecânicos que geram este movimento. O custo energético é maior na caminhada de amputados quando comparada a caminhada de indivíduos sem restrições físicas. Variáveis mecânicas e energéticas de amputados não foram extensivamente estudadas. Nosso objetivo foi avaliar a influência de diferentes velocidades, no recovery, no custo de transporte (C), na eficiência mecânica (Eff), na transdução pendular (Rint), trabalho mecânico, na estabilidade dinâmica, bem como verificar a associação entre a estabilidade dinâmica com recovery, custo de transporte e eficiência mecânica. Participaram do estudo 10 indivíduos amputados transfemurais (com joelho hidráulico e pé em fibra de carbono). Foi realizada cinemetria 3D (quatro câmeras de vídeo) e simultaneamente a análise do consumo de oxigênio. Foram determinadas cinco velocidades de caminhada, após definir a velocidade auto selecionada. Além da velocidade auto selecionada foram definidas duas velocidades acima e abaixo das VAS. Para os dados de Recovery, custo de transporte, eficiência mecânica, transdução pendular, trabalho total, trabalho externo, travalho vertical, trabalho horizontal, trabalho interno e estabilidade dinâmica foram utilizadas rotinas desenvolvidas em Matlab®. A velocidade influencia nos parâmetros mecânicos e energéticos da caminhada de amputados transfemurais. Os maiores valores para: economia de caminhada, Recovery, transdução pendular, eficiência mecânica, trabalho mecânico interno e vertical, e estabilidade dinâmica foram obtidos na máxima velocidade de caminhada dos sujeitos. As correlações entre o coeficiente de variação do comprimento da passada e Recovery, custo de transporte e potência metabólica foram moderadas. Esses resultados são de grande relevância para a área clínica e ponderados durante o processo de reabilitação desses indivíduos. / The human walking is an important movement used by man, but extremely complex in relation to the energetic and mechanical mechanisms that generate this movement. The energy cost of gait is greater in amputees than in normal subjects. Mechanical and energetics variables in amputees have not been extensively studied. Our objective was to assess the influence of speed in recovery, cost of transport (C), mechanical efficiency (Eff), pendular transduction (Rint), mechanic parameters, dynamical stability, well as to verify agreement between dynamical stability with recovery, C, Eff and metabolic power. Materials and Methods: ten transfemoral amputees (with hydraulic knee and carbon fiber foot) were selected in the study. Simultaneously three-dimensional (3D) kinematics data (four cameras) and oxygen consumption were collected at five speeds, two above and two below self-select one. The Recovery, C, Eff, Rint, dynamical stability, were processed using Matlab software. Mechanics and energetics of amputee walking were influenced by speed. In maximal speed of amputee walking were reported greatest values, like: recovery, cost of transport (C), mechanical efficiency (Eff), pendular transduction (Rint), internal and vertical mechanical work and dynamical stability. Pearson correlation between dynamical stability and Recovery, C, Eff and metabolic power were moderate. These results are clinical relevance and should be considered during the rehabilitation of these individuals.

Although artificially selected goldfish exhibit swimming performance decrements, with the most derived morphotypes more affected, they can be utilized to explore functional design and movement pattern principles in aquatic vertebrates. Drag, steady swimming kinematics (tailbeat frequency, amplitude, stride length), energetics (standard and active metabolic rate), fast-start performance (average and maximum velocity and acceleration), stability in yaw and roll and propulsive muscle ultrastructural characteristics (mitochondrial volume density and spacing, myofibril diameter and capillary to fibre ratio in red and white muscle) were measured for four morphotypes: common, comet, fantail and eggfish, of comparable length (≈ 5 cm). A performance “pairing” (common and comet; fantail and eggfish) was a recurrent theme for most performance parameters. Vertebral numbers (30), segment lengths (≈ 0.85 mm) and standard metabolic rates (≈ 140 mg O2 kg-1 hr-1) are exceptions where values are the same. Fantail and eggfish drag and drag coefficients (referenced to frontally projected area ≈ 0.6 - 0.9) were higher (requiring more thrust at any given velocity) than those for the more streamlined common and comet (≈ 0.3 - 0.6; P < 0.05). This is reflected in kinematics; tailbeat frequency and stride length at any given velocity for the common and comet are lower and higher respectively than that of the fantail and eggfish (P < 0.05). Common and comet fatigue times are not significantly different from that of their ancestor, Crucian carp (P > 0.05), and are lower than those of the fantail and eggfish (P < 0.05). The cost of transport of the common and comet (≈ 0.6 mg O2 kg-1 m-1) is accurately predicted from the mass scaling relationship for fish (P > 0.05), but values for the fantail and eggfish (≈ 1.3 mg O2 kg-1 m-1) are not (P < 0.05). Eggfish steady swimming (dorsal fin absent) was characterized by rolling and yawing motions associated with significant energy losses. Common and comet fast-start performance (average velocity ≈ 0.45 m s-1, maximum velocity ≈ 1.2 m s-1, average acceleration ≈ 7.5 m s-2, maximum acceleration ≈ 35 m s-2) was similar to that of other locomotor generalists (e.g. trout). Eggfish maximum acceleration (≈ 5 m s-2) is poor due to the absence of inertial and lifting contributions to thrust from the dorsal fin and energy wasting rolling motions. Artificially selected fish can bear upon fitness related adaptations associated with form and movement, providing insights into the “performance envelope” of natural systems subject to ecological speciation.

Although artificially selected goldfish exhibit swimming performance decrements, with the most derived morphotypes more affected, they can be utilized to explore functional design and movement pattern principles in aquatic vertebrates. Drag, steady swimming kinematics (tailbeat frequency, amplitude, stride length), energetics (standard and active metabolic rate), fast-start performance (average and maximum velocity and acceleration), stability in yaw and roll and propulsive muscle ultrastructural characteristics (mitochondrial volume density and spacing, myofibril diameter and capillary to fibre ratio in red and white muscle) were measured for four morphotypes: common, comet, fantail and eggfish, of comparable length (≈ 5 cm). A performance “pairing” (common and comet; fantail and eggfish) was a recurrent theme for most performance parameters. Vertebral numbers (30), segment lengths (≈ 0.85 mm) and standard metabolic rates (≈ 140 mg O2 kg-1 hr-1) are exceptions where values are the same. Fantail and eggfish drag and drag coefficients (referenced to frontally projected area ≈ 0.6 - 0.9) were higher (requiring more thrust at any given velocity) than those for the more streamlined common and comet (≈ 0.3 - 0.6; P < 0.05). This is reflected in kinematics; tailbeat frequency and stride length at any given velocity for the common and comet are lower and higher respectively than that of the fantail and eggfish (P < 0.05). Common and comet fatigue times are not significantly different from that of their ancestor, Crucian carp (P > 0.05), and are lower than those of the fantail and eggfish (P < 0.05). The cost of transport of the common and comet (≈ 0.6 mg O2 kg-1 m-1) is accurately predicted from the mass scaling relationship for fish (P > 0.05), but values for the fantail and eggfish (≈ 1.3 mg O2 kg-1 m-1) are not (P < 0.05). Eggfish steady swimming (dorsal fin absent) was characterized by rolling and yawing motions associated with significant energy losses. Common and comet fast-start performance (average velocity ≈ 0.45 m s-1, maximum velocity ≈ 1.2 m s-1, average acceleration ≈ 7.5 m s-2, maximum acceleration ≈ 35 m s-2) was similar to that of other locomotor generalists (e.g. trout). Eggfish maximum acceleration (≈ 5 m s-2) is poor due to the absence of inertial and lifting contributions to thrust from the dorsal fin and energy wasting rolling motions. Artificially selected fish can bear upon fitness related adaptations associated with form and movement, providing insights into the “performance envelope” of natural systems subject to ecological speciation.

O acidente vascular encefálico (AVE) do tipo isquêmico representa 80% dos casos de AVE no Brasil; este é resultante da interrupção do suprimento sanguíneo ao tecido cerebral. Uma sequela decorrente da lesão do neurônio motor superior é a hemiparesia, estado caracterizado pela perda parcial da força muscular de um lado do corpo. Por sua vez, a locomoção hemiparética é característica comum após o episódio de AVE. Clinicamente os pacientes apresentam alterações no controle motor, excessiva co-ativação muscular e espasticidade, assim como mudanças nas propriedades passivas dos músculos. Além disso, os padrões cinemáticos alterados acarretam em diminuição da amplitude de movimento e consequentemente redução na velocidade de caminhada e maior dispêndio energético. Dessa maneira, um melhor entendimento de como os acometimentos segmentares afetam o trabalho mecânico total (Wtot) e o custo de transporte (C) da caminhada de indivíduos com AVE pode auxiliar na avaliação da eficácia das intervenções terapêuticas. Assim, este estudo tem como objetivo mensurar e comparar o Wtot e o C em cinco diferentes velocidades de caminhada entre sujeitos hemiparéticos crônicos decorrente do AVE e sujeitos saudáveis. A amostra foi composta por 6 pacientes com diagnóstico clínico de AVE do tipo isquêmico e 10 sujeitos saudáveis (grupo controle). Foi utilizada a cinemetria tridimensional e um sistema de análise metabólica para aquisição dos dados. Os resultados indicaram que os pacientes com AVE apresentaram Wtot e C significativamente maior em relação aos sujeitos do grupo controle. O aumento no Wtot se deve principalmente ao maior trabalho mecânico vertical (Wv) e trabalho mecânico interno (Wint), e.g., Wint rotacional do membro não acometido teve contribuição de até 50% para o resultado de Wint. Os pacientes AVE apresentaram C significativamente maior nas baixas velocidades de caminhada; enquanto nas demais velocidades os grupos foram similares. Pode-se concluir que em reposta ao prejuízo para o sistema de movimento em decorrência ao AVE, os pacientes adaptam a marcha e realizam compensações com o objetivo de minimizar os déficits funcionais. / Ischemic stroke represents 80% of stroke cases in Brazil, and it is result of a blood flow interruption into brain tissue. This upper motor neuron injury leads to hemiparesis, state characterized by partial loss of muscle strength at one side of the body. Hemiparetic gait is a common feature after stroke episode. Clinically, patients present alterations in motor control, excessive co-activation and muscle spasticity, as well as changes in passive properties of muscles. Moreover, kinematic deviations lead to a decreased range of motion and consequently a reduction in walking speed and a higher energy expenditure. Thus, a better understanding of how segmentar impairments affect total mechanical work (Wtot) and cost of transport (C) in stroke patients allows verifying the efficacy of therapeutic interventions. Therefore, this study aims to measure and compare Wtot and C at five different walking speeds between hemiparetic post-stroke patients and healthy subjects. Six patients with clinical diagnostic of ischemic stroke and ten healthy subjects (control group) participated in the present study. Three-dimensional motion analysis system and metabolic analysis system were employed for data acquisition. Results indicated that stroke group showed significantly higher Wtot and C than control group. The increased Wtot is mainly due to higher vertical mechanical work (Wv) and internal mechanical work (Wint), i.e., higher Wint rotational of uninvolved limb; accounted for a 50% contribution to Wint results. The stroke group had significantly higher C at lower speeds, while for other speeds both groups were similar. In conclusion the stroke group showed a compensatory response in the neuromuscular system, on which stroke patients adapted their gait mechanics in order to minimize functional deficits.

A caminhada humana é um movimento importante utilizado pelo homem, porém extremamente complexo em relação aos mecanismos energéticos e mecânicos que geram este movimento. O custo energético é maior na caminhada de amputados quando comparada a caminhada de indivíduos sem restrições físicas. Variáveis mecânicas e energéticas de amputados não foram extensivamente estudadas. Nosso objetivo foi avaliar a influência de diferentes velocidades, no recovery, no custo de transporte (C), na eficiência mecânica (Eff), na transdução pendular (Rint), trabalho mecânico, na estabilidade dinâmica, bem como verificar a associação entre a estabilidade dinâmica com recovery, custo de transporte e eficiência mecânica. Participaram do estudo 10 indivíduos amputados transfemurais (com joelho hidráulico e pé em fibra de carbono). Foi realizada cinemetria 3D (quatro câmeras de vídeo) e simultaneamente a análise do consumo de oxigênio. Foram determinadas cinco velocidades de caminhada, após definir a velocidade auto selecionada. Além da velocidade auto selecionada foram definidas duas velocidades acima e abaixo das VAS. Para os dados de Recovery, custo de transporte, eficiência mecânica, transdução pendular, trabalho total, trabalho externo, travalho vertical, trabalho horizontal, trabalho interno e estabilidade dinâmica foram utilizadas rotinas desenvolvidas em Matlab®. A velocidade influencia nos parâmetros mecânicos e energéticos da caminhada de amputados transfemurais. Os maiores valores para: economia de caminhada, Recovery, transdução pendular, eficiência mecânica, trabalho mecânico interno e vertical, e estabilidade dinâmica foram obtidos na máxima velocidade de caminhada dos sujeitos. As correlações entre o coeficiente de variação do comprimento da passada e Recovery, custo de transporte e potência metabólica foram moderadas. Esses resultados são de grande relevância para a área clínica e ponderados durante o processo de reabilitação desses indivíduos. / The human walking is an important movement used by man, but extremely complex in relation to the energetic and mechanical mechanisms that generate this movement. The energy cost of gait is greater in amputees than in normal subjects. Mechanical and energetics variables in amputees have not been extensively studied. Our objective was to assess the influence of speed in recovery, cost of transport (C), mechanical efficiency (Eff), pendular transduction (Rint), mechanic parameters, dynamical stability, well as to verify agreement between dynamical stability with recovery, C, Eff and metabolic power. Materials and Methods: ten transfemoral amputees (with hydraulic knee and carbon fiber foot) were selected in the study. Simultaneously three-dimensional (3D) kinematics data (four cameras) and oxygen consumption were collected at five speeds, two above and two below self-select one. The Recovery, C, Eff, Rint, dynamical stability, were processed using Matlab software. Mechanics and energetics of amputee walking were influenced by speed. In maximal speed of amputee walking were reported greatest values, like: recovery, cost of transport (C), mechanical efficiency (Eff), pendular transduction (Rint), internal and vertical mechanical work and dynamical stability. Pearson correlation between dynamical stability and Recovery, C, Eff and metabolic power were moderate. These results are clinical relevance and should be considered during the rehabilitation of these individuals.