The Influence And Related Mechanism Of PNF Drawing For The Lower Limb Muscle Strength

Purpose:This study based on the analysis of isometric muscle strength,muscle power,force and CMJ height of analysis after different warm-up activity,To explore PNF stretching for the duration of temporary impact force and related mechanism.So as to deepen the effect of the PNF stretching on the strength and reasonable use PNF stretch before training competition technology.Method:100 male healthy subjects were selected.In study,we stretch their quadriceps,hamstring and gluteal muscles by ergometer.Based on VRS-5,we determine the PNF threshold value.Using dynamometer table of Kistler,CMJ performance is determined.This study included 15 healthy young men,measuring isometric muscle testing of the leg extensor muscle group after different warm-up activity on the same day,recording the change of the myoelectricity,the force and the CMJ performance at the same time.Result:The MVIC at 30 s After the stretching was significantly increased than the MVIC before the stretching(p < 0.05),There were no statistically significant difference between the TMVIC at 30 s after the stretching,the TMVIC before the stretching,and between the TMVIC at 30 s after the stretching and the TMVIC at 15 min after the pulling.Comparing force sensing before the stretching,the force sensing at the 30 s after the stretching and the stretching force at 15 min after the stretching were significantly decreased(p < 0.05).The iEMG of the rectusfemoris,vastus lateralis muscle,and vastusmedialismuscle at 30 s after the stretching was significantly increased than the iEMG before the stretching(p < 0.05).The muscle voltage of he rectusfemoris,vastus lateralis muscle,and vastusmedialismuscle at 15 min after the stretching test was significantly increased than the muscle voltage before the stretching.The root meansquare(RMS)of the vastus lateralis muscle at 30 s after the stretching were also significantly increased than the RMS before the stretching.However,The statistically significant differences wasn't observe in the RMS,vastus lateralis muscle,and vastusmedialismuscle between at 15 min after the stretching and before the stretching.Conclusion:The short time of PNF stretching wasn't helpful for the CMJ performance.There is no obvious effect on the muscle strength of lower limb.Moderate PNF stretching training can increase the isometric muscle strength temporarily,but the effect of explosive power isn't obvious.PNF stretching can improve the capacity of the sports unit and promote muscle activation.Besides,PNF stretching can also enhance the muscle strength awareness.