Experimental Study On The Relationship Between The Number Of PNF Pulls And The Attenuation Rate Of Hip Joint Flexibility Of Female College Students

Good flexibility is an important prerequisite for individuals to participate in sports activities, will involve joint flexibility stretching before exercise in the process of sports teaching and training, to improve the students' movement in the process of performance after stretching ability and muscle injury prevention. PNF stretching method is used more and more frequently in sports teaching and training because of its remarkable stretching effect and its own training characteristics.In real life, physical education teachers and coaches focus too much attention on the improvement of the flexibility of the joints, which is obtained from the stretch training. The flexibility of the joints before the exercise is for the stretching process of the movement of services, and thus the end of the stretch after the joint flexibility of the effect of exercise practice is more valuable. It is of great significance to guide the teaching and training of science to explore the change of the lasting effect of the flexibility after the end of the stretch. The study by the PNF tension of female college students Fala stretched out right thigh muscle muscles. By stretching the joints in tension after a period of time. To study the changes of different PNF stretching times,through the analysis of the experimental results conclude that research results in order to provide effective theoretical reference for sports teaching and training.In this experiment, 48 subjects were randomly divided into four groups, control variables, respectively 0, 1, 2, 3 PNF stretch on the four groups, the experimental process by shooting video recording, after the end of the experiment by analyzing the video and combining the calculation of trigonometric functions obtained for each group of subjects after the end of each measurement in tensile moment of hip flexion angle value, by processing the data obtained after different times of PNF stretching time variation of subjects under the hip flexion angle is the change trend, thus draws the conclusions:(1) The 1-3 PNF stretch in this experiment can improve the flexibility of hip joint of female college students, right hip and PNF stretch of female college students, from the angle of the hip flexion tensile value increases along with the increase of PNF stretch frequency. The increase of the flexion angle of the hip was decreased with each increase.(2) The experiment in different PNF stretch frequency was "stretching effect" of different duration, as follows: with the increase of the number of tensile tensile hold time the flexibility effect is longer, under the experimental conditions, a "contraction relaxation" model of the PNF stretch to make joint flexibility stretching increases for 5 minutes two times in a row, tocontract and relax of flexibility of PNF model can make the tensile stretching increases for 9-11 minutes, three consecutive tocontract and relax mode can make the flexibility of the PNF stretching effect lasts for 15 minutes after stretching.(3) The following 3 PNF stretch stretching hip, hip joint activity increased by stretching from the angle to the stretching angle attenuation to stretch before the initial level of this period of time, increase the decay rate of the joint angle with the drawing times slowed in the drawing effect "keep the section, with the increase of PNF tensile times, the decay rate of flexibility of stretching increases is slow, the tension after the ability to maintain joint flexibility is strong, repeated tension can attenuate the speed of flexibility of slow stretching.(4) At the end of the whole stretch, the attenuation rate of the flexibility of the hip joint showed a trend of first fast and slow,and finally tended to be gentle until all disappeared.Finally, based on the results of this study, the author puts forward some suggestions on the basis of the actual situation of physical education teaching and training. In physical education, physical education teachers should be based on the number of the specific content of course reasonable arrangements for the PNF stretch,to enable students to meet the appropriate class of flexibility and training each time requirements, and should pay attention to the tension of flexibility of decay process in physical teaching and training, reasonable arrangements for the connection between the content of practice the students in the classroom, ensure that any stage of the movement of the body can be suitable as a guarantee of flexibility, so can improve the students' ability to exercise performance and avoid sports injury and other negative phenomena occur.