| Objective:The use of unstable training can activate more core muscle groups,improve the athletes’ neuromuscular coordination ability and indirectly improve the athletes’ strength level.The unstable training needs to select the specific features and simulate the movement pattern during the movement.Water bag is a kind of unstable training equipment,the upper limb can use it to make a variety of movements,so as to produce an unstable disturbance from top to bottom.However,there are few studies on water bag training,and people often cannot find the water bag and irrigation amount suitable for their own specifications when using the equipment.By comparing the percentage of EMG activation of rectus abdominis,external oblique,erector spine and rectus femoris muscle with different filling coefficient of water bag under the same load,and comparing the left-right direction,forward-back direction and offset area of the body pressure center,the best filling coefficient of water bag was analyzed and explored to stimulate the muscle activation when using water bag.Methods:In this paper,the most effective filling coefficient of the water bag for muscle activation was explored by analyzing the EMG of the core and main muscle groups of the water bag with different filling coefficients.18 subjects with more than two years of resistance training experience were recruited.Using barbell and three water bags with full coefficients of 70%,48%and 38%,respectively,the subjects performed squats over the top on a force measuring table.The EMG data of rectus abdominis,external oblique,erector spinal muscle and rectus femoris muscle as well as the rocking degree of the body center of pressure(COP)were analyzed.Results:Different types of load can significantly affect the RMS value of muscle,F=4.201,P=0.007<0.05,and there is no interaction effect between different load types and muscle types.The simple effect between different loads was examined and it was found that only the RMS of rectus femoris had a significant difference between the barbell group and RED(38%filling coefficient)P=0.018<0.05,while other muscles had no statistically significant difference between different load types.In the analysis of the results of different pressure loads on the over-top squat,it was found that the water bag with 48%filling coefficient in the left and right direction of COP was significantly improved compared with the water bag with 70%filling coefficient(P=0.021<0.05)and 38%filling coefficient(P=0.031<0.05),with statistical significance.Similarly,in terms of offset area,the water bag with 48%filling coefficient significantly increased compared with the other two filling coefficients,with a very significant difference between 70%(P=0.007<0.05)and 38%(P=0.024<0.05).Conclusion:1)When using the same load to complete the functional action of the over-top squat,stable and unstable conditions did not cause changes in core muscle activation.(2)There was no significant difference in the degree of core muscle activation when using water bags with the same load and different filling coefficients during the functional action of squatting over the top.(2)The over-top squat with a water bag with a filling coefficient of 48%can cause more body sway than other filling factors.(3)During the over-top squat with the water bag,the active degree of the active muscle did not decrease compared with the stable condition. |
