Respostas neuromusculares de atletas profissionais de futebol durante pré-temporada: Parâmetros para a prevenção de lesões

Abstract

The pre-season in football is the period with the greatest workload as it is relatively short (between 4 to 6 weeks). This period is characterized by physiological adaptations to the training load, but this improvement may not be enough to deal with the intensity and stress associated with competitive football, leading to an increased risk of injuries. The purpose of this investigation was to assess the muscular strength of the knee extensors and flexors muscles, agility and functionality between dominant leg (DL) vs. non-dominant leg (NDL) of elite soccer players during pre-season. Twenty-two healthy male elite soccer players (25.1 ± 3.8 years; 182.1 ± 5.9 cm; 79.3 ± 5.4 kg; body fat 14.6 ± 3.8%) from a club of the Brazilian second-division soccer league participated in this study. All soccer players underwent three tests to assess strength, power, and physical performance with an interval of 48 hours inter-sessions. During the first assessment session, isokinetic tests were performed in which athletes performed maximal isokinetic concentric and eccentric contractions, as well as maximal isometric contractions. In the second and third assessment sessions, single leg step down and agility tests were performed, respectively. Maximum voluntary isometric contraction (MVIC) results showed a significant difference (p<0.04) between DL compared to the NDL for absolute and relative values. However, the isokinetic variables of knee extensors at 60°·s-1 (total work and power) were significantly higher (p <.03) in NDL. Pearson's correlation was found to be significant between MVIC and single leg step down (SLSD) test for DL (r = 0.70, p = .0001) and NDL (r = 0.58; p = .002). The results confirm that DL shows greater isometric strength than NDL. However, NDL revealed an increase in the total work and power output in elite soccer players. Furthermore, the SLSD test is recommended because it proved to be a good method for evaluating muscle strength by a positive correlation with MVIC.