Effect Of Different Factors On Hamstring Flexibility And Muscle Strength Under Static Stretching Training

Objective: To explore the effects of stretching time,tensile strength and delay time after static stretching on hamstring muscle strength and flexibility.Enrich the research on the influence of different factors of static stretching training,and provide some reference suggestions for people to choose an appropriate stretching scheme according to their own sports practice.Research methods: the methods adopted in this study include literature,experiment and mathematical statistics.The content of the experimental method is: 30 subjects were subjected to static stretching intervention with different stretching time and different tensile strength,and the changes of hamstring flexibility and muscle strength after stretching were analyzed.The composition of stretching time is: 30 s stretching,45 s stretching and 60 s stretching.The time of45 S is defined as the medium tensile strength and the time of 45 S is defined as the high tensile strength.At the same time,the test results of hamstring flexibility and muscle strength immediately after pull-down extension,5min and 10 min after stretch were compared and analyzed.The results are as follows:（1）the influence of static tension at different time.Flexibility:the range of motion of the joint was significantly improved before and after stretching,with a very significant difference（P < 0.01）;There was no significant difference between the groups immediately after stretching.Muscle strength: there was no significant difference in the decrease of hamstring flexor muscle strength at 30 s and 45 s before and after the experiment;When the stretching time was 60 s,the hamstring muscle strength decreased significantly（P <0.01）;It was found that there was little change between stretching 30 s group and stretching 45 s group（P > 0.05）,and there was significant difference between stretching 30 s group,stretching45 s group and stretching 60 s group（P < 0.05）.（2）Influence of different strength on static tension.Flexibility: before and after stretching,there was no significant difference between the low-strength stretching group and before the experiment,and there was significant difference between the high-strength and medium strength stretching groups and before the experiment（P < 0.01）.The comparison between groups immediately after stretching showed that there were significant differences among the three tensile strengths of low strength,medium strength and high strength（P < 0.01）.Muscle strength: compared with that before the experiment,there was significant difference in highstrength tension（P < 0.01）,and there was no significant difference in low-strength and medium strength.The comparison between groups immediately after stretching showed that there were significant differences between high strength and medium strength and low strength（P < 0.01）.（3）Effect of different delay time on static stretching.Flexibility delay effect: low strength stretching has little effect on improving flexibility,and there is no significant difference between each time point.The effect of improving flexibility after high-strength stretching can be maintained until 10 min after stretching,and there is no significant difference between each time point after stretching.There was significant difference between other combinations immediately after stretching and 5 min and 10 min after stretching（P < 0.05）,and there was no significant difference between 5 min and 10 min after stretching,indicating that the improvement effect of flexibility would decrease significantly 5 min after stretching.Muscle strength delay effect: there was no significant difference between immediately after highintensity stretching and 5 min after stretching,and immediately after stretching and 10 min after stretching;There was significant difference between 5 min and 10 min after stretching（P <0.01）.There was no significant difference between other delay time points.Research conclusions:（1）analyze the effect of static stretching at different times on flexibility: stretching for 30 s or more can achieve the ideal effect on flexibility.Analyze the impact of static stretching at different times on muscle strength: stretching at 45 s and below has less negative effect on muscle strength,and stretching at 60 s and above has a significant decrease in muscle strength.（2）Analyze the influence of static stretching with different strength on flexibility: the flexibility will increase significantly after stretching with medium and high strength,especially with high strength.The effects of static stretching with different strength on muscle strength are analyzed: the stretching with low and medium strength has little effect,and the muscle strength is obviously damaged after stretching with high strength.（3）The effect of improving flexibility immediately after static stretching is the most obvious,but it will show a downward trend after stretching.The effect of high-strength stretching can be maintained for 10 minutes,and the flexibility effect of other groups decreased significantly at 5 minutes.The muscle strength decreased most immediately after static stretching,but it will gradually recover after stretching.The low and medium strength stretching has little effect on the muscle strength,and the high-strength stretching muscle strength recovered significantly 10 minutes after stretching.