Relationship of muscle imbalances in football players: a cross-current study

Abstract

Aim: To get information about isokinetic knee muscle strength imbalance of Brazilian athletes from elite football in the Under17, Under20 and adult professional categories and to explore relationships with their playing positions. Materials and Methods: The sample composed by 105 athletes. They were divided into three categories by age: Under17, Under20 and Professional. The playing positions were established as follows: Goalkeeper, External Defender, Defender, Defensive Midfielder, Midfielder and Forward. All subjects were submitted to isokinetic strength test, performed for the quadriceps and isquiosurais musculature, at 60º / s with five maximum repetitions. Results: After descriptive analysis, it was observed that 49% of athletes have imbalance. After analyzing the categories, 40% of Under17 athletes showed imbalance, 37.1% of Under20 athletes and 38.2% of professional athletes presented imbalance. Regarding the bilateral imbalance, it was noted that 20% of Under17 athletes, 28.6% of SUB-20 athletes and 32.4% of professionals had imbalance. It was also observed that 66.7% of the goalkeepers had unilateral imbalance and 33.3% bilateral. However, 70.6% of the forwards show some kind of imbalance (uniateral or bilateral). Conclusions: Therefore, almost half of the evaluated athletes presents muscle imbalance, and athletes Under17 and Under20 are not physically suitable to train at the level of professional players, given that they have greater level of muscle imbalance and hence potentially increased risk of injury. Furthermore, the Forward position stands for the highest degree of muscle imbalance between the six positions analyzed.