递增负重卧推和卧推抛起的动力特征及表面肌电活动研究

Comparison of the Dynamic Characteristics and Electromyographic between Bench Press and Bench Throw

比较卧推抛起(bench throw,BT)与卧推(bench press,BP)在动作的力、速度和功率等方面的差别,并分析BT练习的适宜负重;结合进行练习时有关肌肉的表面肌电活动情况,探讨动作速度对抗阻工作时神经肌肉活动方式的影响。方法:12名男大学生以个人30%、50%、70%、90%1 RM的杠铃重量分别进行相等负重的BP和BT动作,测量两种动作时杠铃运动的力、平均速度和峰功率;同时记录胸大肌、肱三头肌和肱二头肌的表面肌电信号,选取平均积分振幅(AEMG)、中位数频率(MF)和平均功率频率(MPF),进行两动作和各负重等级之间的多重分析比较。结果:在相同重量的条件下,BT动作在各级负重上均产生了较BP更高的峰功率,在30%和50%1 RM负重时较BP具有显著更高的动作速度;在相等负重的BP和BT时,胸大肌和肱三头肌的AEMG在动作之间差异不显著,但均与负重重量同步增加;在BT时,胸大肌的MF在所有负重等级上较BP时显著更大,在30%、50%1 RM负重时MPF较BP时显著更大。结论:BT动作更加有利于上肢爆发力的训练,以50%1 RM的负重进行BT练习较为适宜;肌肉工作时要实现更快的速度和产生更大功率,需要对主动肌激发更高频率的神经冲动。

Objective： The purpose of this experiment was to compare the difference of force, velocity, power and the surface eleetromyographic （sEMG） between bench press（ BP） and bench throw（BT）. Methods： 12 male un- dergraduates practiced barbell BP and BT at 30% ,50% ,70% ,90% 1 RM, respectively. The force, average ve- locity and peak power of action were measured, the sEMG signal of musculi pectoralis major, musculus triceps brachii, and musculus biceps brachii during action were recorded, to mensurate the average amplitude （AEMG） , median frequenee （ MF）, mean power frequence （MPF） of electromyographic. For all measures, difference be- tween BP and BT at each barbell load was compared. Results： The results indicated that at the same barbell weight, BT generated significant higher peak power than BP at all weight grade, and higher average velocity at 30% and 50% 1 RM. The AEMG of musculi pectoralis major and musculus triceps brachii had no significant differ- ence between BP and BT at all weight grade, yet the AEMG showed a positive relationship with weight loads. Dur- ing BT, the MF of musculi pectoralis major were higher than BP at all weight grade, and the MPF were higher than BP at 30% and 50% 1 RM. Conclusion ： It could concluded that BT exercise was more effective for the explo- sive strength training of upper limbs, 50% 1 RM was a economical weight load to practice BT; To achieve more higher velocity and power, the agonist muscle should be excited by nerve impulse with more high-frequency.