RESUMO
Objective To explore the effect of acute endurance exercise on the balance control,maximum contraction of the back extensor and the anticipatory postural adjustments(APAs) and compensatory postural adjustments (CPAs) of the lumbar vertebra.Methods Seventeen male students from a police college participated in this study voluntarily.Three tests were performed right before and after the 10000 meters run:the single foot standing test with eyes closed,maximum contraction test of the back extensor and arm-rising test.The maximum voluntary contraction (MVC) of the back extensor and the time of standing with eyes closed were collected.The sEMG activities of lumbar erector spinae(LES) and Lumbar multifidus(LMF) as lumbar stable muscles were recorded.The pre-activation time and integrated EMG of APAs and CPAs were calculated.Results Before and after the 10000 meters run,no significant difference was observed in MVC,but the time of single foot standing decreased significantly.On the condition of the internal postural perturbation,the LES was activated significantly earlier and the APAs IEMG of LMF decreased significantly after the run,but no significant difference was observed in the pre-activation time of LMF and APAs IEMG of LES.The CPAs IEMG of LES and LMF both decreased significantly after the run.Conclusions The acute endurance exercise of 10000 meters run does not cause fatigue of lumbar stable muscles,but it has an effect on the performance of body balance control.It has effects on the postural control strategies of the central nerve system in response to the internal sudden postural perturbation,resulting in the earlier pre-activation of LES to compensate the decreased activation magnitude of LMF.