This study involved a comparison of 5 kinematic-based algorithms to detect heel strike (HS) and toe-off (TO) events during human locomotion at different speeds. The objective was to assess how different running and walking speeds affect contact event determination during treadmill locomotion. Thirty male runners performed walking at 5 km/h and running at 9, 11, and 13 km/h on a treadmill. A kinematic system was used to capture the trajectories of 2 retroreflective markers placed at the subject’s right heel and second metatarsal. A footswitch device was used to determine the “true” times of HS and TO compared with 5 kinematic-based algorithms. The results of the current study illustrated that speed influences the HS error in the vertical position and horizontal velocity algorithms, and the TO error in the vertical position and horizontal velocity algorithms. This difference was found in the transition from walking to running; however, higher running speeds did not affect the error estimation. Higher accuracy was found with combined algorithms, namely, one using vertical acceleration and position and another using horizontal and vertical position with no influence from different locomotion speeds. Therefore, these algorithms are recommended in studies where speed is self-selected because they work well for a broad range of locomotion velocities.

ResumoContexto: A prática de esportes apresenta efeitos bené cos para o sistema cardiorrespiratório e muscular, para a função comportamental e para a saúde mental. Entretanto, não se sabe o papel do esporte de alto nível na construção de per s resilientes. Objetivos: O objetivo do presente estudo foi comparar resiliência, qualidade de vida e ansiedade de ex-atletas de alto rendimento de ginástica artística, de outros esportes e indivíduos não atletas. Métodos: Participaram do estudo ex-atletas de ginástica artística (n = 17), de outras modalidades (n = 15) e indivíduos não atletas (n = 30). AbstractBackground: e practice of sports has bene cial e ects on cardiorespiratory and muscle systems, behavioral function, and mental health. However, the inuence of elite sports on the development of resilience is not known. Objectives: e objective of the present study was to compare resilience, quality of life, and anxiety in ex-athletes of artistic gymnastic and other sports with non-athletic individuals. Methods: Ex-artistic gymnastics athletes (n = 17), ex-athletes of other sports (n = 15), and non-athletic individuals (n = 30) were recruited. Structured anamneses as well as depression, anxiety, resilience and quality of life scales were applied in all groups. Results: Signi cant di erence between groups were found in resilience (p = 0.001), anxiety (p = 0.049), general health status (p = 0.044), and emotional aspects of quality of life (p = 0.002). Ex-athletes showed greater resilience and better quality of life regarding to emotional aspects than non-athletes. Discussion: Sport seems to contribute to the development of a more resilient pro le and better quality of life.

Introduction: Obesity is a major global public health issue and approximately half of the population is classified as overweight. Many studies have investigated gait modification in obese people; however, no research has been carried out in overweight subject´s gait influence. Methods: The goal of this study was to identify biomechanical changes on gait in overweight subjects by the application of principal component analysis (PCA). Two groups of adults participated of this study: overweight (n = 9; 25.0 < Body Mass Index < 29.9 kg/m 2), and normal-weight (n = 15; 20.0 < Body Mass Index < 24.9 kg/m 2. Three-dimensional kinematics of the lower limb and ground reaction forces (GRF) were recorded during gait. PCA was performed on data. Results: PCA evidenced statistical differences at the first principal component (PC) of the sagittal ankle movement, anteroposterior and mediolateral GRF, as well as at the third PC of the sagittal hip movement and mediolateral GRF. Overweight subjects walked with reduced ankle plantarflexion at toe-off and reduced hip flexion at the heel strike and at mid swing, as well as a reduced hip extension during push off. Additionally, increased anteroposterior and mediolateral GRF on overweight subjects were observed. Conclusion: overweight individuals might adjust their gait characteristics in response to their increased weight to reduce overload lower limbs joints. These gait modifications pointed to a possible increase in the risk of musculoskeletal pathology in this population.

Synchrogram and iCP tools currently employed for measuring CLC are not appropriate because they indicate the occurrence of this phenomenon even among subjects who ran on different days and times of each other.

A B S T R A C T ObjectiveTo assess the influence of carbohydrate and added pea protein concentrate supplementation on muscle recovery after a military operation called Leader's Reaction Test. MethodsTwenty-four soldiers from the Brazilian Army were divided into three equal groups (n=8). They received either carbohydrate (0.8.g/kg body weight/h), carbohydrate+carbohydrate (1.0.g/kg body weight/h), or carbohydrate+protein (0.8 g/kg body weight/h of carbohydrate + 0.2 g/kg body weight/h of protein), immediately, 60, and 120 minutes after the Leader's Reaction Test. Prior, immediately after and 24 hours after the Leader's Reaction Test, maximal isometric strength and body composition were assessed. Blood samples were also collected for later analysis of concentrations of lactate dehydrogenase and creatine kinase. ResultsTwenty-four hours after the Leader's Reaction Test, maximal creatine kinase levels were significantly lower than its levels immediately after (501.00 ± 422.09 versus 275.29 ± 242.08 U/L (carbohydrate); 616.88 ± 291.45

Introduction and objective: Delta efficiency (DE) and oxygen uptake kinetics (K O 2 ) are influenced by muscle metabolic parameters and oxygen transport. The aim of this study was to determine the difference in DE and K O 2 in three effort intensities in both genders. Methods: Fifty-six subjects (26 women) were submitted to a graded maximal exercise test (GXT) on cycle ergometer to determine the maximum oxygen uptake ( O 2max ), maximal power output (W max ), anaerobic threshold (AT) and respiratory compensation point (RCP). The AT and RCP were determined using the V-slope and E / O 2 methods; the RCP using the relationship O 2 versus E both by two investigators. The DE and K O 2 have been considered as a slope between O 2 versus Watts and O 2 versus time (s), respectively, from the beginning of test until AT (S 1 ), from AT to RCP (S 2 ) and from RCP to O 2max (S 3 ), determined by linear regression analysis. Results: Regarding DE, significant differences were observed between S 1 versus S 2 (p = 0.001), S 1 versus S 3 (p = 0.001) and S 2 versus S 3 (p = 0.006). There was no significant difference (p = 0.060) or interaction (p = 0.062) between men and women. For K O 2 , significant differences were observed between S 1 versus S 3 (p = 0.001) and S 2 versus S 3 (p = 0.001) in both genders. Significant differences (p = 0.001) and interaction (p = 0.006) were observed between men and women, in the last parameter. Conclusions: DE decreases with increasing intensity of power output, but there are no differences when comparing men and women. On the other hand, women present faster K O 2 than men.

RESuMoIntrodução: A reprodutibilidade da atividade eletromiográfica de superfície (EMG) é mais estudada em protocolos que envolvem contrações isométricas. Alguns fatores relacionados às contrações dinâmicas podem contribuir para a instabilidade do sinal mioelétrico e dificultar a reprodutibilidade da medida da EMG. Objetivo: Determinar a reprodutibilidade teste-reteste e quantificar o erro téc-nico da medida da frequência mediana (FM) e da amplitude (root mean square, RMS) da EMG, em contrações dinâmicas e estáticas. Métodos: Dez sujeitos foram testados em dois dias, sendo a atividade EMG registrada na maior porção do bíceps braquial. No primeiro dia foi feito o teste de uma repetição máxima (1RM) e de contração voluntária máxima (CVM). No segundo dia foram realizadas duas séries de 10 contrações dos flexores do cotovelo com 75% de 1RM, entremeadas por 1 h em repouso. Antes de cada série foi realizada uma CVM. Resultados: Para a FM e RMS foi observado alto coeficiente de correlação intraclasse para o sinal do bíceps braquial (CCI = 0,90-0,98 para a FM; CCI = 0,89-0,94 para o RMS) e de baixo para moderado coeficiente de variação (CV = 2,5-6,2% para a FM; CV = 14,6-16,3% para o RMS) em ambos os testes. Não foi observada diferença significativa entre teste e reteste (p > 0,05). Conclusão: A FM e o RMS apresentam alta confiabilidade e baixo a moderado erro em contrações estáticas e dinâmicas, possibilitando o uso da EMG para investigação da fadiga e de desordens neuromusculares.Descritores: músculo esquelético, fadiga muscular, análise espectral, eletromiografia. for RMS) and low to moderate coefficient of variation ABStRAct Introduction: Reproducibility of electromyographic activity (EMG) is the most studied in protocols involving isometric contractions. Some factors related to dynamic contractions may contribute to the instability of the myoelectric signal and affect the reproducibility of the measurement of EMG. Objective: To determine the test-retest reproducibility and quantify the technical error of the measurement of the median frequency (MF) and amplitude (root mean square, RMS) of the surface EMG in static and dynamic contractions. Methods: Ten subjects were tested in two days with the EMG activity recorded for the greatest portion of the biceps brachii tendon. In the first day the subjects did one test of maximum repetition (1MR) and maximal voluntary contraction (MVC

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