Efeitos do treino técnico na assimetria funcional dos membros inferiores de jovens futebolistas

Abstract

The functional asymmetry of the lower limbs has been considered an important factor in the performance of soccer players. In this sense, the purpose of this study was to examine the effects of specific technical training for non-preferred foot on its utilization rate during the game; and to investigate if interruption of a technical training programme for the non-preferred foot influences its utilization rate during the game. Fifty young soccer players were randomly divided into two groups: G1 (n=26, 9.50±1.04 years) and G2 (n=24, 9.58±1.02 years). At the beginning of the first 4 months, each player's use of both feet during the game was assessed. The study lasted eight months divided into two periods of four months. In the first training period G1 was subjected to a technical training programme directed to the non-preferred foot, while G2 had no constraints on the use of both feet. At the end of the 4th month the two groups were newly assessed. During the second training period G1 and G2 reversed the training programmes. After the 8 months of training the evaluation of the utilization rate of both feet during small-side games was again performed. The main conclusions of the study were: (i) the technical training of the non-preferred foot allowed significant increases in its utilization rate during small-sided games; (ii) the interruption of such training partially reversed this effect. Thus, technical training for the non-preferred foot should be systematically performed in order to maintain the positive effects induced over functional asymmetry.

Influence of technical training with an increased share of non-dominant leg exercises on reduction in lower limbs functional asymmetry in young soccer players

“…the significant reduction of asymmetry in short shots (passes) and reduction in the total level of asymmetry in all the evaluated skills (by 4.8%) suggests the effectiveness of the applied variant of movement symmetrization in the group of 11-year-old soccer players. A similar training program followed by younger athletes (mean age, 9.5 ± 1.0 years) also led to a reduction in functional asymmetry (number and effectiveness of technical actions with the ball) observed during the game (5v5 small-sided game) [17]. technical training with an increased share of NDL resulted in even bigger effects in older players (aged over 18 years).…”

“…Less effort seems to have been devoted to the asymmetry of other technical skills (e.g. ball handling, shooting with the medial part of the foot or with the internal instep) [13][14][15][16] and few studies have attempted to determine the asymmetry during the game (smallsided games) [1,17,18]. It seems that the level of asymmetry varies depending on a concrete technical ability and reduces as the player reaches the level of a champion.…”

“…In the part devoted to technical improvement (mostly this was 30-45 minutes of each training) in the first variant, the players used only NDL (100/0, i.e. they spent 100% of the time for the improvement of the NDL) [1,17,[19][20][21]. In the second variant, they performed exercises with the proportion of 75/25 to the benefit of the NDL (75% NDL, 25% DL) [2,22].…”

“…It should be emphasized that most experiments assumed the variant of training in which athletes used exclusively NDL (100/0). It turns out that this type of training is effective in reducing functional asymmetry of lower limbs, evaluated in both isolated technical tests [19,20] and in small-sided 5v5 games [1,17]. However, the training was mainly aimed to improve the abilities of NDL.…”

“…NDL) and, for the contrast, periodical performing the movement with the opposite limb (here: DL) is conducive to greater control, 'refreshes' the kinaesthetic sensations, reduces fatigue of the limb, consequently leading to improved technique [2,23,24]. In addition, performing the exercises with both NDL and DL leads to learning by one limb from the other (termed interlateral transfer), which is not observed when only one leg is used [1,17,20]. It should be emphasized that most studies in this field have evaluated players aged 12 and older (12-20 years of age) [1,2,[19][20][21][22].…”