Effects Of FIFA 11+ On Isometric Strength Of Lower Limbs And Running Performance Of Young Football Players

Objective:Aiming at the high injury risk in football,various preparation activities for preventing injury have been proposed.In many programs,FIFA 11+ is generally considered to effectively reduce the risk of injury for football players,However,there is still no research on the effect of FIFA 11+ on the strength of isometric muscles of young football players,and it is still controversial whether it can improve the running performance related to football,the enhancement of athletic performance can further prove the rationality of this preparation activity.As one of the risk factors for injury,isometric muscle strength is related to many common football injury risks.It can be continuously monitored and adjusted for reversal in a short period of time.It can be obtained through a Hand-held dynamometry(HHD),which is relatively simple.Therefore,this study intends to conduct 8-week FIFA 11+ intervention for young football players to observe the changes in the hip and knee isometric muscle strength characteristics,30-meter sprint,and “5 × 25” shuttle run test before and after8 weeks.Investigate the effects of FIFA 11+ on young football players.Methods:Twenty young male football players in the U13 age group of Beijing Yicheng BTV Football Club were selected as the research objects and randomly divided into intervention group(n=10)and control group(n=10).All players were trained 3 times a week.The intervention group was FIFA11 + before training.The control group was routinely warmed up for 20 minutes.The study lasted 8 weeks.Before and after the study,the subjects 'isometric muscle strength characteristics(including maximum strength and relative strength)of the lower extremity hip and knee joints,the 30-meter sprint time,and the “5× 25” shuttle run test time were measured.The data of the control group and the intervention group were compared using the paired sample t-test.The baseline comparison and post-test comparison of the control group and the intervention group were compared using the independent sample t-test.All data were processed and analyzed by SPSS 20 and set in all hypothesis tests,P <0.05,indicating that the difference was significant.Results:(1)The comparison in the maximum strength group showed that the maximum isometric contraction strength(MVC)of bilateral knee flexors of the players in the intervention group increased significantly compared with that before the intervention,P <0.05,but there was no significant change in the control group(P> 0.05).MVC ofbilateral hip abduction in the intervention group was significantly higher than before intervention(P<0.05),but there was no significant change in the control group(P>0.05).The dominant leg side(right)knee hamstring / quadricus strength ratio(H/Q)of the players in the intervention group was significantly higher than that before the intervention(P<0.05),and there was no significant change in the control group(P>0.05).(2)The comparison in the relative strength group showed that the relative strength of the dominant lower extremity knee extensor muscles(MVC/BW,BW is weight)of the intervention group was significantly lower than before the intervention(P<0.05).The relative strength of the knee flexors in the non-dominant side of the intervention group was significantly higher after the intervention than before the intervention(P<0.05).The relative strength H/Q ratio of the dominant leg-side knee joint in the intervention group was significantly higher than that before the intervention,P<0.05.Comparison between groups showed that the relative strength of bilateral knee flexors in the intervention group was significantly higher than that in the control group after 8 weeks,P<0.05;(3)The results of running performance indicators showed that the 30 m sprint performance of the intervention group and the control group improved to varying degrees after 8 weeks(P<0.05);however,the 30 m sprint time of the intervention group players was significantly shorter than that of the control group after 8 weeks(P<0.05);The results of the "5×25" shuttle run test showed that the intervention group players had a significant improvement after 8 weeks(P<0.05),while the control group had no significant improvement,P>0.05.Conclution:(1)FIFA 11+ for 8 weeks can significantly enhance the long abduction strength of hip joints of young football players,knee isometric flexor strength,and balance the isometric strength of the dominant knee flexor and extensor group.(2)FIFA 11+ can significantly improve the 30 m sprint ability and “5 × 25” shuttle running performance of young football players,and improve their running performance level.