Study On Correlation Between Kinematic Factors Of Lower Limb And Running Economy Of Middle Distance Running Athletes

Purpose:Running economy(RE) or runing efficiency reflects the energic utilization by measuring the oxygen uptake at submaximal running speed. It’s an important determinant of endurance running performance. Running economy has different variation in different groups and individuals, which explains partly the changes of endurance performance.elite runners may utilize elastic energy more effectively, which, in combination with minimum concentric work, leads to improvements in their running performance.Influence Factors on Running Eeonomy are including all kinds of aspects, such as type of muscle fiber,pulmonary ventilation,heart rate as Well as gender,age,fatigue and so on.The aim of this study was to determine whether runners who have a better RE values are differ in their running kinematics from those runners who have a lower RE values.Methods:The purpose of this study was to explore the kinematic factors affecting running economy, We have chose9highly homogeneous runners (age:21.35±0.68years old;height:(176.6±4.88) cm; weight:70.05±4.55kg, training period:(2.57±0.58) years as the Subjects form Beijing Sport University, The Cortex Biophysik Metamax system(MAX-2) was adopted to analysize the indicators of VO2max and RE.exercise load is12km/h,in the next day,whole subjects were running1500meters in simulated situations,Data were collected using one high-speed cameras operating at50Hz with a two-dimensional pan and shixun system. Joint angle and angular velocity data were smoothed using cut-off frequencies of10Hz by Zatsiorsky’smodel.The aim of this test was to determine whether subjects are differ in their running kinematics.Results:RE average oxygen uptake (48.51±3.59ml/(kg·min))has a certain correlation between the subjects with some lower extremity kinematics, RE values with the subject from the ground kicking phase angle between the two legs, frog legs knee angle into a very significant negative correlation (p<0.01), with periodic motion, the height difference between the center of gravity was a very significant positive correlation (p<0.01); and kicking stages of trunk inclination was significantly negatively correlated relationship (p<0.05); and torso maximum angle difference was significant positive correlation (p<0.01).Conclusion:The results show that the rank correlation coefficient was a little significant between the running economy and the kinematic principal components, we concluded that the kinematic factors which we have chose were the factors affecting the running economy.Lower limbs tomp,thigh angle, knee angle,torso angle and other biomechanical parameters have a certain degree of influence on the RE when vacated, may be factors that cause a discrepant between the level of RE. the more obvious the torso off the ground phase of the inclination of the smaller and the whole cycle during exercise sloshing around the trunk inclination more obvious, the level of athletes are worse.