Abstract
Objectives:
Lower extremity injury risk in youth soccer is often attributed to lower extremity strength deficits/imbalances and lack of dynamic stability. The ’FIFA11+Kids’ program is a neuromuscular training (NMT) program designed to address these issues in youth soccer players. However, its effectiveness has not been evaluated in preadolescent females, despite studies showing an elevated risk of such injuries in compared to males. The purpose of this study was to assess the impact of the ’FIFA11+Kids’ training on dynamic stability, agility, power, and lower body strength in preadolescent female competitive soccer players.
Methods:
Seventy-four female youth soccer players were recruited and completed this study spanning a competitive season (~13wks) following allocation to either the NMT(n=45/10±1yrs) or CONTROL(n=29/10±1yrs) groups randomized by team. The NMT group completed the ‘FIFA11+Kids’ program at practice biweekly incorporated into their standardized warm-up. The CONTROL group performed a standardized warm-up alone. Functional testing was performed before and after the intervention: Y-balance (YBT) for balance and dynamic stability; Strength testing (knee extension/flexion); Agility and power testing assessed via the pro-agility test and hop testing (HT). A 2x2 ANCOVA repeated on time and covaried on baseline testing was used to compare changes in measures within and between groups. Correlation and Z-test analysis evaluated the relationship between age and test performance. (Type-I error, ∝=0.05).
Results:
The NMT group was observed to have improvements in posteromedial(↑3.54%±2.44, p=0.001) and posterolateral(↑3.25%%±2.79, p=0.013) YBT reach. The CONTROL group experienced a ↓2.54%±2.17 reduction in anterior reach (p=0.012). Following training, only the NMT group recorded faster times on the pro-agility test (↓0.2±0.09seconds, p=0.049) and compared to the CONTROL group at post-intervention (↓0.33±0.11seconds, p=0.003). No significant changes were detected in hamstring strength for either group. Both groups had similar significant improvements in quadriceps strength (NMT:↑6.0±1.3lbs, p<0.001 | CONTROL:↑4.7±1.6lbs, p=0.015). Both groups improved similarly in single-leg hop distance, with only the CONTROL group demonstrating improvement in triple-hop distance. Age was observed to be correlated with all performance measures (p<0.05), having a stronger relationship with agility(r=0.603) and power(r=0.594) measures compared to YBT(r=0.374)(p<0.05).
Conclusions:
The ’FIFA11+Kids’ program led to modest but significant improvements in dynamic stability and agility in preadolescent female soccer players, which may reduce injury risk. However, it did not improve strength or the knee flexion/extension ratios often linked to injury risk reduction. We conclude the FIFA11+Kids program may benefit from including additional lower extremity strengthening activities. While age was correlated with improved performance measures, natural improvement in dynamic stability with age appears to be less likely compared to other metrics, emphasizing a potential need to train these qualities in preadolescent female athletes.