不同负荷快速离心——向心卧推练习动力学参数及sEMG研究

Study on Dynamic Parameters and sEMG of Fast Centrifugal-Centrifugal Bench Press under Different Loads

目的:比较常规卧推练习(TBP)与快速离心速度下卧推练习(FBP)时的动力学参数及sEMG变化特点,为选择适宜的卧推负荷和卧推方式提供依据。方法:以12名大学生作为受试者分别进行40%、60%、80%1RM的TBP和FBP练习,测量其推起时的速度、功率和力值等动力学参数,及相关肌肉向心阶段的IEMG和RMS变化情况。结果:①在相同的各级负荷上FBP较TBP可产生更大的功率输出和峰值力量,40%—60%1RM范围内FBP比TBP有更大的动作速度。②相同负荷上TBP与FBP比较主动肌IEMG不存在显著性差异(P>0.05);胸大肌RMS在40%1RM负荷时存在非常显著性差异(P<0.01),在60%1RM负荷时存在显著性差异(P<0.05);肱二头肌IEMG在80%1RM负荷时存在非常显著性差异(P<0.01),RMS在80%1RM负荷时存在显著性差异(P<0.05)。结论:FBP可以有效提高峰值功率和最大力量,中小负荷时比TBP有更大的动作速度;中小负荷时,FBP比TBP有利于胸大肌更好地储存与释放弹性势能,提高肌肉的工作效率;大负荷时FBP拮抗肌收缩加强,要注意拮抗肌与主动肌的协同练习。

Objective:To compare the dynamic parameters and sEMG changes of TBP and FBP so as to provide a basis for choosing suitable load and mode of TBP.Methods:TBP and FBP exercises of 40%,60%and 80%1RM were performed on 12 college students.The dynamic parameters in TBP and FBP such as speed,power and force were measured,and the changes of IEMG and RMS in the centrifugal phase of related muscles were also measured.Result:①FBP can produce greater power output and peak power than TBP at the same level of load,and FBP has greater motion speed than TBP in the range of 40%~60%1RM.②There was no significant difference in IEMG between TBP and FBP at the same load(P>0.05);RMS of pectoralis major muscle had significant difference at 40%load(P<0.01),at 60%1RM load(P<0.05);IEMG of biceps brachii had significant difference at 80%1RM load(P<0.01);RMS had significant difference at 80%1RM load(P<0.05).Conclusion:FBP can effectively increase peak power and maximum strength,and has greater motion speed than TBP at medium and small loads;FBP can better store and release elastic potential energy than TBP at medium and small loads,and improve the working efficiency of muscles;FBP antagonist muscle contraction is strengthened at high loads,and attention should be paid to the cooperative exercise between antagonist muscle and active muscle.