A Study On The Effect Of Different Stretching And Combination Methods On The Explosive Power Of Lower Limbs Of Track And Field Students

Objective: To compare the effects of different stretching methods（dynamic stretching,foam axis stretching,dynamic stretching + foam axis stretching,foam axis stretching +dynamic stretching）on the explosive power of lower limbs;to observe the effects of different stretching methods on the explosive power of lower limbs at three time points: immediately,5min and 10 min,to find out the best time point for the effects of different stretching methods on explosive power;and to explore the potential factors affecting explosive power at different time points and different stretching methods;to provide a theoretical basis for the selection of stretching methods during warm-up for daily training and competition.METHODS: Fourteen male athletes（age: 20.6±0.8 years;height: 174.5±5.7 cm;weight:69.4±8.0 kg）in the special selection class of athletics in the College of Physical Education of Sichuan Normal University were selected as the study subjects.The experiment was a repeated measures design in which all subjects were randomized to four stretching protocol interventions（dynamic stretching,foam axis stretching,dynamic stretching + foam axis stretching,foam axis stretching + dynamic stretching）after performing jogging;one of the explosive strength index tests（standing long jump,vertical jump touch height,Margaria-Kalamen,30 m run）was randomized after the intervention;each experiment was recorded separately The baseline values of the pre-test,and the results of the explosive strength indexes immediately,5 min and 10 min after the intervention were recorded for each experiment;finally,a two-factor repeated measures ANOVA was performed on the experimental data using SPSS22.0.Results:（1）At the 5min time point,the combination of foam shaft and dynamic stretching was the best compared with the rest of the stretching methods,with a significant difference（P < 0.05）.（P < 0.05）;at the 10 min time point,the standing long jump performance was better than the dynamic stretching + foam shaft combination（P < 0.05）.（2）The test index was longitudinal jump touch height,and there was no significant difference after the intervention of the four stretching methods（P>0.05）.（3）The test index was Margaria-Kalamen,and the immediate,5min and 10 min scores after the foam axis stretching intervention were better than the baseline values,and the 5min scores were better than the immediate scores（P < 0.05）.After the dynamic stretching intervention,the 5min and 10 min scores were better than the baseline values,and the 5min score was the best,followed by the 10 min score（P < 0.05）.The immediate,5min and 10 min scores after the combination of foam axis + dynamic stretching intervention were better than the baseline values,and the best score was at 5min,followed by 10min（P < 0.05）.The immediate,5min,and 10 min scores after the dynamic stretching + foam axis combination were better than the baseline values,and the 5min score was the best（P < 0.05）.When the time point was immediate,the foam axis + dynamic stretching and dynamic stretching + foam axis combination had the best performance compared with the rest of the stretching methods,with significant differences（P < 0.05）;there was no significant difference between the foam axis + dynamic stretching combination and dynamic stretching + foam axis combination（P >0.05）.At the time point of 5 min,the foam axis + dynamic stretching combination had the best performance compared with the rest of the stretching methods,followed by dynamic stretching（P < 0.05）.When the time point was 10 min,the foam axis stretching was the worst compared with the rest of the stretching methods（P < 0.05）.（4）The test index was 30 m,and the performance of 5min and 10 min after the foam axis stretching intervention was better than the baseline value,and the 10 min performance was the best（P < 0.05）.After dynamic stretching intervention,5 min and 10 min were better than the baseline value,and 10 min was the best,followed by 5 min（P < 0.05）.The immediate,5min,and 10 min performance of the combined foam axis + dynamic stretching intervention was better than the baseline value,and the 10 min performance was the best,followed by 5min（P< 0.05）.5min and 10 min performance of the combined stretching intervention was better than the baseline value,and the 10 min performance was the best,followed by 5min（P < 0.05）.When the time node was immediate,the combination of foam axis + dynamic stretching was better than the combination of dynamic stretching + foam axis（P < 0.05）.When the time point was 5 min,the foam axis stretching was the worst compared with the rest of the stretching methods（P < 0.05）;the combination of foam axis + dynamic stretching was better than the combination of dynamic stretching + foam axis（P < 0.05）.When the time point was10 min,the foam axis stretching was the worst compared with the rest of the stretching methods（P < 0.05）;the combination of foam axis + dynamic stretching was the best,followed by dynamic stretching（P < 0.05）.Conclusion:（1）All four stretching methods had different degrees of improvement in lower limb explosive strength compared to no stretching.（2）The best effect of the four stretching methods on explosive strength was the combination of foam axis stretching + dynamic stretching.（3）The effect of stretching on explosive strength had a time delay effect,with the best effect reaching five minutes after stretching.（4）The effect of using foam shaft stretching before dynamic stretching was better than that of using foam shaft stretching after dynamic stretching.