Abstract Aim: To compare muscle function of knee extensors, gait parameters, and physical function in older women with and without knee osteoarthritis (KOA) and to associate these parameters to the KOA incidence in this population. Methods: Sixteen older women with KOA (66.9 ± 5.5 years; 74.9 ± 10.0 kg; 157.9 ± 0.9 cm; 30.2 ± 5.0 kg/m2) and fourteen healthy counterparts (control group: CG; 68.8 ± 5.8 years; 68.9 ± 10.5 kg; 158 ± 0.06 cm; 27.4 ± 4.0 kg/m2) participated in this study. Muscle function, physical function, and gait parameters were evaluated in both groups. The Western Ontario and McMaster Index (WOMAC) questionnaire was answered only by the KOA group. A correlation was performed to verify if KOA incidence was associated with muscle function, physical function, and gait parameters. Results: KOA group showed lower peak torque at 60°/s (30%; p = 0.003) and 180°/s (37%; p < 0.001), greater acceleration time at 60°/s (382%; p < 0.001), lower cadence (12.2%; p = 0.002), slower gait speed (19.5%; p < 0.001) and greater stride time (12.5%; p = 0.001) than CG group. However, there was no difference between groups in physical function (p < 0.0045). The KOA incidence presented a negative correlation with peak torque (rho = −0.602; p < 0.001), cadence (rho = −0.533; p = 0.002), gait speed (rho = −0.633; p < 0.001), stride length (rho = −0.517; p = 0.003) and a positive correlation with stride time (rho = 0.533; p = 0.002) and acceleration time (rho = 0.655; p < 0.001). Conclusion: Our findings suggest that knee osteoarthritis may impair the function of the knee extensors muscles and gait parameters. An association between the ability to produce force rapidly and gait speed with the KOA incidence in older women was also observed.

Abstract Aims: One of the common sequelae of chronic abuse of alcohol and/or illicit drugs is the impairment of body balance control, caused by long-term neurological damage. This study aimed to investigate the postural control of individuals hospitalized for the treatment of substance use disorder (initial phase) and to compare the results obtained by a control group. Method: For this, One-hundred fourteen individuals hospitalized for the treatment of substance use disorder and eighty-eight healthy controls, all males, were analyzed. Body mass, height, and waist circumference were measured. Were performed a balance test in a static upright position with feet side by side using a plantar pressure platform. Results: Individuals with substance use disorder have shown significantly lower results on body balance compared with controls. Individuals with chemical dependence showed balance results open-eyes, similar/lower than control subjects with close-eyes. Still, those who used only alcohol or alcohol combined with other illicit drugs presented worse results. Finally, impairments in body balance variables showed a significant correlation with age and substance time of use. Conclusion: Even in the early stage of treatment, substance use disorder considerably impairs the balance of the investigated men. The worst results were found in alcohol-dependents (alcohol alone or alcohol combined with other drugs).

Abstract Aims: This study tested whether performing exergames with and without additional external load could induce to different internal load demand for young adults. Methods: Fifteen young women (24.4 ± 4.06 years) participated in the study. Electromyography (EMG) activity, heart rate (HR) and overall and local rating of perceived exertion (RPE) were determined in “Just Dance” and “Ski” exergames without additional external load and with additional external load of 5% of body mass attached bilaterally to the ankles in “Just Dance” and using a weight vest in “Ski”. Results: EMG, HR and overall RPE presented similar responses between loads in both exergames (p>.05). However, local RPE differentiate internal load only in “Just Dance”, with higher values with additional load (with additional load: 11.2 ± 2.1 RPE; without additional load: 10.3 ± 1.4 RPE; p = .037). Conclusion: Therefore, performing exergames with an additional external load of 5% of young women body mass did not induce different internal load demand in “Just Dance” and “Ski” exergames compared to performing such games without external load. However, the greater local RPE in “Just Dance” exergame after adding the external load suggests that a higher amount of load (i.e., > 5% of body mass) to this population may generate different internal load demand.

RESUMO Aproximadamente 21% das quedas em idosos ocorrem como consequência de tropeços ao caminhar. Há uma escassez de informações referentes à variabilidade e à confiabilidade dos parâmetros cinemáticos da marcha em diferentes dias de avaliação, sobretudo com idosos. Buscou-se analisar a variabilidade e a confiabilidade (intra e inter-dia) dos parâmetros espaço-temporais e angulares da marcha de idosos, após a indução de tropeço controlado. Oito idosas participaram do estudo. O tropeço foi induzido durante o início da fase de balanço da marcha. Foram analisados os dados cinemáticos das tentativas de marcha. A variabilidade e confiabilidade dos parâmetros espaço-temporais da marcha foram verificados através do coeficiente de variação (CV), do coeficiente de correlação intraclasse (ICC) e do erro padrão de medida (SEM). A variabilidade dos parâmetros espaço-temporais e angulares intra e inter-dia foi baixa para a maioria das variáveis, à exceção da flexão plantar. O SEM foi baixo para todos os parâmetros. A confiabilidade intra-dia foi moderada a alta para os parâmetros espaço-temporais e angulares; A confiabilidade inter-dia foi baixa a moderada para todos os parâmetros. As variáveis não diferiram entre instantes e dias. Apesar do padrão de marcha não ter alterado deve ser analisado com cautela em estudos que incluam intervenção, particularmente para os parâmetros angulares.

ABSTRACT Approximately 21% of the falls in older adults occur due to tripping, while walking. There is a paucity of information regarding the gait variability and reliability when a tripping is induced in different days mainly with elderly. It was aimed to analyze the variability and the reliability (intra- and inter-day) of spatiotemporal gait parameters and joint angles after controlled tripping in older adults. Eight healthy older women participated. The trip was induced during the early-mid swing phase on the transposing segment and the kinematic data was obtained from trials. The variability and reliability of spatiotemporal gait parameters and joint angles during the gait cycle were checked through the coefficient of variation (CV), the intraclass coefficient correlation (ICC) and the standard error of measurement (SEM). The variability of spatiotemporal and intra- and inter-day angular parameters was low for most variables, except for plantar flexion. The SEM was low for all parameters. Intra-day reliability was moderate to high for the spatiotemporal and angular parameters. Inter-day reliability was considered low to moderate for all parameters. The variables did not differ between instants and days. Experimental procedures demonstrate that the walking pattern did not change, but should be considered with caution in studies that include intervention, particularly for angular parameters during gait.

RESUMO O objetivo dessa revisão sistemática foi analisar os processos de adaptação transcultural e validação da Escala de Percepção Subjetiva de Esforço de Borg (6-20) e de suas instruções durante o exercício em adultos e idosos. A busca foi realizada nas bases de dados da área da saúde, esporte e psicologia (Pubmed, ScienceDirect, Bireme (BVS), PsycINFO, SportDiscus e Scopus) e os descritores em inglês e português foram padronizados para todas as bases de dados (“exercise”/”exercício”; “validity”/”validade”; “borg scale”/”escala de borg”; “perceived exertion”/”percepção de esforço”; e “validation”/”validação”). Entre os 1488 artigos encontrados, foram selecionados 14 artigos para análise. Os principais resultados encontrados foram que a adaptação transcultural (Cantonês e Japonês) foi reportada em apenas quatro artigos. Os critérios mais baixos de qualidade metodológica foram aqueles relacionados a definição de percepção de esforço, a instrução e familiarização com a Escala. Os resultados indicam que a maioria dos estudos não realizou o processo de adaptação transcultural e além disso, só a validade concorrente foi utilizada como método de validação. Portanto, é necessário realizar adaptação transcultural da Escala de Borg (6-20) principalmente na língua portuguesa, além dos diferentes tipos de validação para se obter resultados mais precisos.

ABSTRACT The aim of this systematic review was to analyze the cross-cultural adaptation and validation processes of Borg’s Rating of Perceived Exertion Scale (6-20) and its instructions during exercise in adults and the elderly. The study was conducted using databases that include the areas of health, sports and psychology (Pubmed, ScienceDirect, Bireme (BVS), PsycINFO, SportDiscus and Scopus), and descriptors in the English and Portuguese languages were standardized for all databases ("exercise" / "exercicio", "validity" / "validade", "borg scale" / "escala de borg"; "perceived exertion" / "percepção de esforço" and "validation" / "validação"). Among the 1,488 items found, 14 articles were selected for analysis. The main findings were that cross-cultural adaptation (Cantonese and Japanese) was reported in only four articles. The lowest-scored criteria for methodological quality were related to the concept of perceived exertion, and the instructions for use and familiarization with Borg’s scale. The results indicate that the majority of the studies did not apply the cross-cultural adaptation process and additionally, that concurrent validity was the only validation method reported. Therefore, it is necessary to carry out the cross-cultural adaptation of Borg’s Scale (6-20), mainly in the Portuguese language, in addition to other types of validation in order to ensure more accurate results.

Abstract The aim of this study was to determine if rating of perceived exertion (RPE) could be used to monitor the internal load during compounded circuit training (CCT) sessions in women. Thirteen young adults women performed three sessions of CCT varying the intensity according to participants' maximum heart rate (50, 70 and 90%HRmax). Throughout the main part of CCT (35min), HR and RPE were measured. Both variables were significantly different among the exercise intensities. However, HR and RPE were not correlated. Probably because HR at the end of exercise was similar to the beginning at 90% and 70% of HRmax intensities, and lower than the beginning instant at 50% of HRmax intensity, whereas RPE increased from the beginning instant to the end of exercise for all intensities. Therefore, RPE is suitable to monitor the internal load during CCT sessions in women due to its possibility to detect the (in)tolerance to exercise, despite of the lack of correlation with HR.

"Fadiga em salto vertical não afeta a coordenação intersegmental e contribuição segmental." O objetivo deste estudo foi descrever a coordenação entre segmentos e suas contribuições durante saltos verticais intervalados realizados até a fadiga. Sete indivíduos visitaram o laboratório em duas ocasiões: 1) foi determinada a altura máxima do salto vertical e realizada familiarização com saltos verticais; 2) participantes realizaram saltos verticais em contramovimento até a fadiga. Foram coletadas variáveis cinemáticas e cinéticas. A altura do salto vertical reduziu 5,5% e duração do movimento aumentou 10%. O ângulo da coxa no instante de reversão do movimento aumentou durante o exercício. A fadiga na sinergia do movimento não influenciou na coordenação intersegmental. Acima de 90% da coordenação entre segmentos foi explicada por um padrão coordenativo. A rotação da coxa foi o que mais contribuiu com o padrão coordenativo, seguido pelo tronco e perna. Portanto, em saltos verticais realizados até a fadiga, a coordenação intersegmental é mantida e a rotação da coxa tem maior contribuição na altura do salto.

The aim of this study was to describe the intersegmental coordination and segmental contribution during intermittent vertical jumps performed until fatigue. Seven male visited the laboratory on two occasions: 1) the maximum vertical jump height was determined followed by vertical jumps habituation; 2) participants performed intermittent countermovement jumps until fatigue. Kinematic and kinetic variables were recorded. The overall reduction in vertical jump height was 5,5%, while the movement duration increased 10% during the test. The thigh segment angle at movement reversal significantly increased as the exercise progressed. Non-significant effect of fatigue on movement synergy was found for the intersegmental coordination pattern. More than 90% of the intersegmental coordination was explained by one coordination pattern. Thigh rotation contributed the most to the intersegmental coordination pattern, with the trunk second and the shank the least. Therefore, one intersegmental coordination pattern is followed throughout the vertical jumps until fatigue and thigh rotation contributes the most to jump height.

"Fatiga salto vertical no afecta a la coordinación entre segmentos y la contribución segmentaria." El objetivo fue describir la coordinación entre los segmentos y sus contribuciones durante los saltos verticales realizadas hasta la fatiga. Siete sujetos visitaron laboratorio dos ocasiones: 1) determinó la máxima altura en el salto vertical y amistad con los saltos verticales; 2) participantes completaron saltos verticales contramovimento la fatiga. Se recogieron las variables cinemáticas y cinéticas. La altura del salto vertical disminuyó 5,5% y la duración del movimiento se incrementó 10%. El ángulo del muslo en instante de inversión del movimiento aumentó durante ejercicio. No hubo efecto de fatiga en sinergia de movimiento para la coordinación de movimientos. Más del 90% de coordinación entre sectores ha sido explicado por un patrón coordinativo. La rotación del muslo fue mayor contribuyente la coordinación de movimientos, seguido por tronco y piernas. En los saltos verticales realizados hasta la fatiga se mantiene coordinación entre segmentos y rotación del muslo tiene mayor contribución en altura del tacón.

Os mecanismos e conceitos da percepção de esforço têm mudado ao longo do tempo. Assim, este artigo de revisão de literatura tem por objetivos: i) investigar as revisões de literatura publicadas a partir de 1982, descrevendo os mecanismos causais de geração da percepção de esforço relatados e; ii) verificar se os conceitos da percepção de esforço acompanharam as mudanças que ocorreram acerca dos seus mecanismos causais. Foram realizadas buscas nas bases de dados PubMed, Science Direct e Scielo com os termos "rate perceivedexertionandreview" e "perceivedexertionandreview". No total, foram incluídos 18 artigos, que tiveram como objetivo principal a percepção geral de esforço em exercício físico. Apesar da antiga existência da teoria do Disparo corolário para explicar os mecanismos causais da percepção de esforço, verifica-se que, após as proposições de Borg, a maior parte da literatura descreve a percepção de esforço através do mecanismo de Feedback aferente, baseada em estudos correlacionais. Apenas em 2009, a teoria original do Disparo corolário reaparece. Quanto aos conceitos, a maioria deles remete ao mecanismo de feedback aferente, utilizando-se de constructos como respostas fisiológicas, estresse, desconforto e dor, que são incongruentes com a teoria do Disparo corolário e apresentam mecanismos distintos aos da percepção de esforço. Portanto, verificou-se que os estudos de Borg influenciaram nos mecanismos e conceitos contemporâneos da percepção de esforço. Com o passar do tempo, houve incorporação de constructos no conceito original de Borg, porém, sempre embasado na teoria do Feedback aferente.

The mechanisms and concepts of perceived exertion have changed over the years. Thus, the objectives of the present literature review were i) to investigate the literature reviews that have been published since 1982 and to describe the proposed causal mechanisms of perceived exertion, and ii) to determine whether the concepts of perceived exertion have accompanied the changes of its proposed mechanisms. Searches were performed in PubMed, Science Direct and Scielo using the terms 'rating of perceived exertion and review' and 'perceived exertion and review'. Eighteen papers whose main objective was to determine the overall perceived exertion during physical exercise were included in the present study. It was observed that, despite the existence of the early corollary discharge theory, after Borg's propositions most of the literature has explained perceived exertion using the afferent feedback theory based on correlational studies. It was only in 2009 that there was a resurgence of the original corollary discharge theory in perceived exertion papers. Most of the perceived exertion concepts are related to the afferent feedback mechanism, using constructs such as physiological responses, stress, discomfort and pain. However, these constructs are incongruent with the corollary discharge theory, presenting physiological mechanisms that differ from those of perceived exertion. Therefore, Borg's studies have influenced contemporary views of the mechanisms and concepts of perceived exertion. Over the years, additional constructs have been incorporated into the original Borg's concept, although always on the basis of the afferent feedback theory.

Os mecanismos que explicam fadiga e exaustão, controle da intensidade e (in)tolerância ao exercício de resistência cardiorrespiratória têm sido estudados há mais de um século. Apesar de diversas teorias científicas atualmente disponíveis, nos últimos cinco anos um novo modelo chamado de Psicobiológico tem sido proposto. Este modelo dá maior importância aos fatores perceptuais e motivacionais em relação aos seus antecessores, bem como a respectiva influência destes fatores no processo consciente de tomada de decisão e controle comportamental. Nesta revisão, nós apresentamos evidências experimentais e sintetizamos os pontos chaves do modelo Psicobiológico que explicam o controle da intensidade e (in)tolerância ao exercício de resistência cardiorrespiratória. Adicionalmente, nós discutimos como o modelo explica as adaptações ao treinamento relacionadas à melhora no desempenho, as manipulações experimentais e suas predições. Ao final, propomos futuras direções para esta área investigativa. O modelo Psicobiológico pode proporcionar uma nova perspectiva aos resultados anteriormente publicados na literatura, ajudando os cientistas a entenderem melhor seus problemas de pesquisa, assim como analisar e interpretar novas evidências mais precisamente.

The mechanisms underpinning fatigue and exhaustion, and the specific sources of exercise-endurance intensity regulation and (in)tolerance have been investigated for over a century. Although several scientific theories are currently available, over the past five years a new framework called Psychobiological model has been proposed. This model gives greater attention to perceptual and motivational factors than its antecedents, and their respective influence on the conscious process of decision-making and behavioral regulation. In this review we present experimental evidences and summarize the key points of the Psychobiological model to explain intensity regulation and (in)tolerance in endurance exercise. Still, we discuss how the Psychobiological model explains training-induced adaptations related to improvements in performance, experimental manipulations, its predictions, and propose future directions for this investigative area. The Psychobiological model may give a new perspective to the results already published in the literature, helping scientists to better guide their research problems, as well as to analyze and interpret new findings more accurately.