ABSTRACT
PURPOSE/BACKGROUND: Strength asymmetries are related to knee injuries in intermittent sports players. The purpose of this study was to examine whether elite futsal players demonstrate strength asymmetries during knee isokinetic testing applying the Croisier et al.21 criteria. METHODS: Forty male elite (27.9 ± 6.5 years) Brazilian futsal players participated in the study. The testing protocol required players to perform concentric contractions of both quadriceps and hamstring muscles at angular velocities of 60 °·s-1 and 240 °·s-1 and eccentric contractions of hamstring at 30 °·s-1 and 120 °·s-1. Conventional (concentric:concentric) and mixed (eccentric:concentric) hamstrings/quadriceps (H/Q) ratios were calculated. Subjects were determined to have an imbalanced strength profile if an athlete had at least two parameters that were asymmetrical across speeds and conditions. Asymmetry was operationally defined as peak torque asymmetry greater than 15% in bilateral comparison, and H/Q ratio less than 0.47 for conventional and 0.80 for mixed conditions. RESULTS: Significant differences were observed between preferred and nonpreferred limbs in the concentric contractions of flexors at 240 °·s-1 and eccentric contractions of extensors and flexors at 30 °·s-1 and 120 °·s-1. However, these asymmetries did not exceed 15%. The conventional and mixed H/Q ratios were greater in the preferred than in nonpreferred limbs, but only the mixed hamstringsecc/quadricepsconc in the nonpreferred limbs showed values lower than recommended (<0.80). In addition, 50% of elite futsal players had preseason strength imbalances per the developed criteria. CONCLUSION: The studied elite futsal players had preseason strength imbalances, which may increase the risk of hamstring injuries. LEVEL OF EVIDENCE: 3.
ABSTRACT
As respostas fisiológicas e perceptuais verificadas durante a caminhada vêm sendo amplamente pesquisadas; contudo, poucas investigações buscaram comparar essas respostas em grupos de diferentes índices de massa corporal durante caminhada em ritmo autosselecionado. O objetivo do presente estudo foi comparar as respostas fisiológicas e perceptuais entre mulheres com peso normal (PN), sobrepeso (SP) e obesas (OB) durante a caminhada em ritmo autosselecionado. Participaram 66 mulheres sedentárias, com idade entre 20 e 45 anos, designadas em três grupos de acordo com o seu índice de massa corporal: (i) PN (18,5 - 24,9kg·m-2, n = 22); (ii) SP (25,0 - 29,9kg·m-2, n = 22); e (iii) OB (> 30,0kg·m-2, n = 22). Cada participante realizou uma sessão de familiarização e duas sessões experimentais (teste incremental máximo e teste de 20 minutos de caminhada em ritmo autosselecionado), a fim de determinar as respostas fisiológicas (frequência cardíaca, FC; e consumo de oxigênio, VO2) e perceptuais (percepção subjetiva de esforço, PSE) de cada sessão. A ANOVA one-way foi empregada para comparar as respostas fisiológicas e perceptuais obtidas durante a caminhada em ritmo autosselecionado entre os três protocolos experimentais, empregando-se o teste post hoc de Tukey com p < 0,05. Embora os sujeitos com obesidade tenham registrado menor velocidade de caminhada (1,30 ± 0,13m·s-1) comparativamente aos com peso normal e sobrepeso (1,69 ± 0,11 e 1,58 ± 0,22m·s-1, respectivamente) (p < 0,05), eles apresentaram similar resposta fisiológica (58,7 ± 8,6; 63,1 ± 12,6; 64,8 ± 11,1 por centoVO2 e 75,1 ± 7,8; 78,8 ± 8,5; 78,7 ± 7,2 por centoFCmax, para os grupos normal, sobrepeso e obeso, respectivamente). Além disso, as respostas perceptuais também não diferiram entre os grupos experimentais (11,6 ± 1,6; 11,7 ± 1,6; 12,2 ± 1,8, respectivamente). Desse modo, pode-se concluir que, independente do IMC, mulheres adultas apresentam respostas fisiológicas e perceptuais ...
Physiological and perceived responses verified during gait have been widely studied; however, few investigations have tried to compare these responses in groups of different body mass indices during gait in self-selected rhythm. The aim of the present study was to compare the physiological and perceived responses among normative (N), overweighed (OW) and obese (OB) women during gait in self-selected rhythm. Sixty-six sedentary women, aged between 20 and 45 years and divided in three groups according to their body mass indices participated in the study: (i) N (18.5 - 24.9kg·m-2, n = 22); (ii) OW (25.0 - 29.9kg·m-2, n = 22) and (iii) OB (> 30.0kg·m-2, n = 22). Each participant performed a familiarization session and two experimental sessions (maximal incremental test and 20m-walking test in self-selected rhythm) to determine the physiological (heart rate - HR and oxygen consumption - O2) and perceived responses (perceived exertion - PE) of each session. One-way ANOVA was applied to compare the physiological and perceived responses obtained during gait in self-selected rhythm among the three experimental protocols, applying the Tukey's post hoc test with p < 0.05. Although the obese subjects have registered lower walking velocity (1.30 ± 0.13m·s-1) compared with the normative and overweighed ones (1.69 ± 0.11 and 1.58 ± 0.22m·s-1, respectively) (p < 0.05), they presented similar physiological response ((58.7 ± 8.6; 63.1 ± 12.6; 64.8 ± 11.1 percentO2 and 75.1 ± 7.8; 78.8 ± 8.5; 78.7 ± 7.2 percentHRmax, for the normative, overweighed and obese groups, respectively). Moreover, the perceived responses did not differ between experimental groups (11.6 ± 1.6; 11.7 ± 1.6; 12.2 ± 1.8, respectively). Therefore, it can be concluded that regardless of the BMI, adult women present similar physiological and perceived responses during gait in self-selected rhythm even when walking in different velocities.
