Author(s): JIANG, L., HE, J., HONG, Y., BAO, D., Institution: BEIJING SPORT UNIVERSITY, Country: CHINA, Abstract-ID: 660

INTRODUCTION:
Extensive research has shown that reducing ground reaction forces (GRF) during landing can reduce the risk of injury. Quadriceps function is thought to potentially reduce GRF. Flywheel Inertial Training (FIT) may be an effective method for enhancing quadriceps capacity, which improves landing phase performance.
METHODS:
Thirty-two healthy, adult males, mean (±SD) age of 21.5(±1.4) years and mean (±SD) training of 5.5(±1.2) years, were randomized to either FIT Group(FG) or Control Group(CG). Upon completion of 3 training sessions and fulfillment of experimental conditions, receiving 6 weeks of flywheel inertial training (Use the inertial weights that are closest to the average speed of 80%1RM per person for each barbell, calculated using Gym Aware；N=16) or barbell training (80% one-maximum repetition; N=16). Both groups underwent 4 sets × 8 reps per session of squat separated by 3-min rest. The outcomes were tuck jump performance, peak vertical ground reaction forces ([P-vGRF] assessed by 10-second Tuck Jump Assessment [TJA]) and dynamic balance assessment including Composite Score (CS), three directions of anterior (ANT), posteromedial (PM) and posterolateral (PL) ( assessed by Y-Balance Test [YBT]).
RESULTS:
The primary two-way repeated measures ANOVA showed significant time effects on TJA scores (p < 0.001), with post-hoc analyses indicating lower post-intervention scores for both FG (p < 0.001) and CG (p < 0.001), and FG scores significantly lower than CG (p < 0.001). P-vGRF during landing showed significant time effects (p < 0.005), with a notable reduction in FIT group post-intervention (p < 0.011), but no significant effects in asymmetric P-vGRF or during other phases (p > 0.075).
Dynamic balance saw significant time-group interactions and main time effects on YBT-CS (Left: p < 0.002; Right: p < 0.010; Left: p < 0.031; Right: p < 0.002), with FG showing improved scores post-intervention (p < 0.000) and against CG (Left: p < 0.044; Right: p < 0.038). ANT and PM directions exhibited main time effects (ANT: Left: p < 0.001; Right: p < 0.003; PM: p < 0.000), and PL direction showed significant time-group interactions (Left: p < 0.003; Right: p < 0.008) and a main effect for the right limb (p < 0.016). Post-hoc analyses highlighted improvements in ANT and PM directions for CG and both groups respectively, and in PL direction, FG showed significant gains compared to pre-intervention (Left: p < 0.002; Right: p < 0.001) and against CG (Left: p < 0.007; Right: p < 0.001).
CONCLUSION:
Although further validation of this hypothesis and exploration of its applicability and efficacy across different sports and populations are warranted in this study. But these findings suggest that Flywheel Inertial Training could further reducing ground reaction forces and increasing the dynamic postural control than traditional training. The insights gained from this study may be of assistance to injury prevention and might provide trainers a more efficient training alternative.