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RESUMO O calçado é um elemento importante para a prática de corrida. As evidências sobre os impactos das características do calçado e de sua prescrição nas lesões de corredores são restritas. Dessa forma, os objetivos deste estudo foram investigar o processo de escolha do calçado por corredores e verificar se variáveis relacionadas ao calçado e seu processo de escolha estavam associadas à presença e recorrência de lesão no último ano. Foi realizado um estudo observacional com 254 corredores que responderam um questionário autoadministrado sobre características demográficas, a prática esportiva, o calçado e o processo de sua escolha, e lesões ocorridas nos últimos 12 meses. O teste qui-quadrado foi empregado para verificar se havia diferença na distribuição das respostas de cada questão, enquanto o teste de regressão logística para verificar se as variáveis relacionadas ao calçado e ao processo de escolha predizem a presença e recorrência de lesão no último ano. Os resultados indicaram que a maioria dos corredores possui tênis específico para a prática esportiva e considera algumas características ao adquiri-lo, como o amortecimento intermediário e a diferença na altura do solado entre a parte posterior e a anterior de aproximadamente 10mm. A maioria indica conhecer seu tipo de pisada, mas não a considera na escolha do calçado. Além disso, a maioria não usa palmilha e não recebeu orientação para a escolha do calçado. O modelo obtido com a regressão não foi significativo. Assim, apesar de os corredores considerarem as características do calçado ao adquiri-lo, essas características e o processo de escolha não foram associados à presença e recorrência de lesão nos últimos 12 meses.

RESUMEN El calzado es un elemento importante para la práctica deportiva de carrera. Sin embargo, es limitada la evidencia sobre los impactos de las características del calzado deportivo y su prescripción sobre las lesiones en los corredores. Por lo tanto, los objetivos de este estudio fueron investigar el proceso de elección de calzado por los corredores y verificar si las variables relacionadas con el calzado y su proceso de elección se asociaron con la presencia y recurrencia de lesiones en el último año. Se realizó un estudio observacional con 254 corredores que respondieron un cuestionario autoinformado sobre las características demográficas, la práctica deportiva, el calzado y el proceso de elección, y las lesiones que se llevaron a cabo en los últimos 12 meses. La prueba de chi-cuadrado se aplicó para verificar la existencia de diferencias en la distribución de respuestas para cada pregunta. Y se utilizó la prueba de regresión logística para determinar si las variables relacionadas con el calzado y su proceso de elección pueden predecir la presencia y recurrencia de lesiones en el último año. Los resultados indicaron que la mayoría de los corredores tienen zapatillas adecuadas para hacer deporte y consideran algunas características a la hora de adquirirlas, como una amortiguación intermedia y la diferencia de altura de la suela entre la parte delantera y la trasera de aproximadamente 10mm. La mayoría afirma conocer el tipo de paso, pero no lo considera a la hora de elegir el calzado. Además, la mayoría no utiliza plantillas y no recibe orientación sobre la elección del calzado. El modelo que se obtuvo con la regresión no fue significativo. Por lo tanto, aunque los corredores tienen en cuenta las características del calzado a la hora de adquirirlo, esas características y el proceso de elección no se asociaron con la presencia y recurrencia de lesión en los últimos 12 meses.

ABSTRACT Running shoes are an essential element for sports practice. Evidence on the effect of the shoe characteristics and prescription in running injuries are scarce. Thus, this study aimed to investigate runners's process of choosing running shoes and to verify whether the variables related to running shoes and their selection process are associated with the presence and recurrence of injuries in the previous year. An observational study was conducted with 254 runners who answered a self-reported questionnaire about demographics, sports practice, shoe characteristics and selection criteria, and injuries in the last 12 months. The chi-square test evaluated whether there was a difference in the distribution of answers to each question. The logistic regression evaluated whether the variables related to shoes and selection criteria predicted injury's presence and recurrence in the previous year. The results showed that most runners had specific shoes for sports practice and considered some characteristics of the shoes to choose them, including intermediate cushioning and a difference in the heel-to-toe drop of approximately 10mm. Most respondents indicated knowing their foot type but not considering it when choosing shoes. Besides, most individuals did not use foot orthotics and did not receive guidance to select their shoes. The model obtained with the regression was not significant. Therefore, despite considering shoe characteristics when choosing it, these features and the selection criteria were not associated with the presence and recurrence of injuries in the previous 12 months.

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The present study compared the effects of a footwear designed to enhance energy return (thermoplastic polyurethane, TPU) vs minimalist shoes on running economy (RE) and endurance performance. In this counterbalanced and crossover design study, 11 recreational male runners performed two submaximal constant-speed running tests and two 3-km time-trials with the two shoe models. Oxygen uptake was measured during submaximal constant-speed running tests in order to determine the RE at 12 km/h and oxygen cost of running (CTO2) at individual average speed sustained during the 3-km running time-trials wearing either of the two shoes. Our results revealed that RE was improved (2.4%) with TPU shoes compared with minimalist shoes (P=0.01). However, there was no significant difference for CTO2 (P=0.61) and running performance (P=0.52) comparing the TPU (710±60 s) and the minimalist (718±63 s) shoe models. These novel findings demonstrate that shoes with enhanced mechanical energy return (i.e. TPU) produced a lower energy cost of running at low (i.e., 12 km/h) but not at high speeds (i.e., average speed sustained during the 3-km running time-trial, ∼15 km/h), ultimately resulting in similar running performance compared to the minimalist shoe.

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The present study aimed to use a Support Vector Machine (SVM) algorithm to identify and classify shod and barefoot running as well as rearfoot and forefoot landings. Ten habitually shod runners ran at self-selected speed. Thigh and leg muscle surface electromyography (EMG) were recorded. Discrete Wavelet transformation (DWT) and Fast Fourier transformation (FFT) were used for the assembly of vectors for training and classification of a SVM. Using the FFT coefficients for the gastrocnemius and tibialis anterior muscles presented the best results for differentiating between rearfoot/forefoot running in the window before foot-floor contact possibly due to these muscles' critical role in determining which part of the foot will first touch the floor. The classification rate was 76% and 67% respectively, with a probability of being random of 0.5% and 4% respectively. For the same terms and conditions of classification, the DWT produced a reduction in the percentage of correctness of 60% and 53% with a probability of having reached these levels randomly of 15% and 35%. In conclusion, based on EMG signals, the use a FFT to train a SVM was a better option to differentiate running forefoot/rearfoot than to use the DWT. Shod/barefoot running could not be differentiated.