Effect Of Different Fatigue Degrees On Lower Limb Biomechanics During Continuous Vertical Jump Landings In Basketball Players

Purposes:In this paper,we focus on comparing and analyzing the lower limb biomechanical indexes of basketball players during continuous vertical jump landings under different levels of fatigue induced by exercise regimens,exploring the effects of exercise fatigue on the changes of lower limb biomechanical indexes during vertical jump landings of basketball players,exploring the potential link between exercise fatigue and changes of lower limb biomechanical indexes,and the potential risk of exercise injury caused by fatigue.Methods:In this study,30 basketball students from Soochow University were selected,and the Vicon infrared motion capture and analysis system and the Kistler three-dimensional force measurement table were used to collect the spatial and temporal characteristics of the basketball players’ continuous vertical jump(the 5th,10th,and 15th jumps in the course of 15 consecutive vertical jumps)at different fatigue levels(NF,MF,and SF),the joint angles of the three joints of the lower limbs,the joint activity,and the peak ground reaction force indicators.The kinematic and spatial parameters,lower limb triple joint angles,joint activity,and peak ground reaction force indicators were collected.The kinematic and kinetic data collected were analyzed using a 3 × 3[kinematic fatigue(NF,MF,SF)× number of jumps(CJ1,CJ2,CJ3)]twofactor repeated measures ANOVA with a test level a=0.05 for the main,interaction and simple effects of kinematic and kinetic data in different groups and different modes.Results:(1)Differences between athletic fatigue:basketball players’ time characteristic parameters at the moment of continuous vertical jump landing,different athletic fatigue had significant effects on basketball players’ continuous vertical jump vacating time and vertical jump height(P<0.01,P<0.01);different degrees of athletic fatigue had significant effects on basketball players’ continuous vertical jump knee flexion maximum moment of occurrence,knee flexion angle and hip angle(P<0.01,P<0.01)(P<0.01,P<0.01);basketball players’ joint activity at the moment of landing of continuous vertical jump,and athletic fatigue had significant effects on knee flexion mobility,ankle mobility,and hip mobility at the moment of landing of continuous vertical jump(P<0.01,P<0.05,P<0.01);basketball players’ peak ground reaction force of continuous vertical jump,and athletic fatigue had significant effects on basketball players’ peak ground reaction force of continuous vertical jump,and athletic fatigue had significant effects on basketball players’ peak ground reaction force of continuous vertical jump.The AGRF at the moment of peak ground reaction force of longitudinal jump had a significant effect(P<0.05).(2)Differences between consecutive longitudinal jumps:basketball players’ time characteristics parameters at the time of landing of consecutive longitudinal jumps,there was a significant effect of different jumps on basketball players’ consecutive longitudinal height(P<0.01);basketball players’ peak ground reaction force of consecutive longitudinal jumps,and the effect of jumping times on MGRF and AGRF at the moment of peak ground reaction force of basketball players’ consecutive longitudinal jumps was significant(P<0.05,P<0.05).(3)Interaction:In basketball players’ continuous longitudinal jump joint angles,there was a significant interaction between different degrees of locomotor fatigue and jump times on ankle internal rotation at the moment of maximum knee flexion in basketball players’ continuous longitudinal jump(P<0.05);in basketball players’continuous longitudinal jump ground reaction force peak,there was a significant interaction between different degrees of locomotor fatigue and jump times on AGRF at the moment of peak ground reaction force in basketball players’ continuous longitudinal jump(P<0.05).(P<0.05).Conclusion:(1)Different sports fatigue had some significant changes on the lower limb biomechanics of basketball players during continuous vertical jump landing,with the deepening of sports fatigue,the landing strategy of basketball players showed a trend of "soft" to "stiff",but the risk of landing injury increased in both fatigue states.(2)Compared with athletic fatigue,the number of consecutive vertical jumps had less influence on the landing strategy of basketball players when landing on vertical jumps,but still increased the lower limb joint load to some extent;(3)The interaction between fatigue and the number of jumps caused unfavorable changes in the lower limb biomechanics of basketball players when landing on consecutive vertical jumps,resulting in a significant increase in the lower limb joint load,which led to a higher risk of athletic injury.higher risk of sports injury.