The incidence of eccentric and isometric hamstring strength asymmetries among U19 youth elite soccer players in Slovakia
Keywords:
Asymmetries, Eccentric strength, Hamstring, Isometric strength, youth soccer playersAbstract
Physical preparation in soccer is requiring individualization through regular monitoring the physical abilities of players. When it comes to injury prevention, muscle strength and performance asymmetries detection is reliable way to identify increased risk for injury. The primary objective of this study was to analyze the incidence of eccentric and isometric hamstring strength asymmetries among U19 youth elite soccer players in Slovakia and provide the necessary information for physical coaches to improve the injury prevention training protocols. Two hundred eighty-six players (Age 17.29 ± 0.65 years, Height 180.75 ± 12.27 centimeters, Bodyweight 72.97 ± 6.67 kilograms) from 14 Slovakian soccer academies participated in testing their eccentric and isometric hamstring strength during the September 2023. The results showed very high incidence of eccentric as well as isometric hamstring strength asymmetries, when almost 47% of all players scored above 10 % difference between the lower extremities in one or both tests. More than 34 % of all players (p < 0.01, d = 0.3) achieved above 10 % inter-limb difference in eccentric hamstring strength and 26.22 % of all players (p < 0.01, r = 0.36) scored above 10 % inter-limb difference in isometric hamstring strength. Surprisingly, when it comes about players position the results are inconclusive, since some positions showed significant inter-limb differences in eccentric strength, but not in isometric strength and vice versa. Nevertheless, since above 10 % difference in strength testing is considered as a caution for increased chance for injury in any sport, our results suggest that for the players who scored higher asymmetries the physical training intervention for minimizing the inter-limb strength differences might be helpful as a part of injury prevention strategy. Further research needs to be conducted to confirm our findings. It might be interesting to compare the history of players injuries with their strength performance.