Nonlinear Analysis on Variability of Pressure Center to Elite Modern Pentathlon Athletes in the Combined Event

The new rule of modern pentathlon has changed the winning law in shooting game,that is,quick shooting after running replaced pistol in prior time.Thus,the impairment of running on the center of pressure for athletes is essential for the hitting rate.This paper uses complexity analysis to evaluate the influence of variability of center of pressure on the hitting rate for an athlete so that the best pattern of center of pressure could be displayed.Methods:We simulated the whole procedure of shooting to record the orbit of aiming point in quiet state and after 1000-meter race,accompanying with which the center of pressure was recorded,then utilized the T-test and rank sum test to evaluate whether there is significant difference between the two states.Meanwhile,nonlinear dynamical methods and Pearson correlation test were used to analyze the relationship between the change of COP and the hit rate.Results:It was found that there is significant increment in complexity of balance under physiological load accompanied by the significant decline of hitting rate compared to quiet state,of which the two have high correlation coherence(0.78).Meanwhile,the results displayed that there are three typical types in the variability of the center of gravity,in which there is only one type we need in practice.Conclusions:In this study,we utilize nonlinear dynamical methods to find the complexity of athletes after running is significantly higher than in quiet,and the variance might be related to the state of athletes own.Meanwhile,the hitting rate decreases significantly after running,which is in high correlation with the change of COP,of which there exist three typical kinds of trajectory orbits.These findings have very important meaning for supporting new index and accordance to our training plan so that our athletes could improve their performances effectively.