Research On Comfort Of Sports Bra Based On Breast Kinematics Parameters

With the rapid economic development and the popularization of healthy consumption concepts,people's pursuit of the quality of life is increasing rapidly.More and more people are choosing fitness,and the number of female fitness is also growing rapidly.At the same time,women's awareness of breast protection is increasing.In addition to sports shoes and sports clothing same as men,they also need sports bras to strengthen breast protection.A suitable bra can protect the breasts and prevent breasts from sagging.An unsuitable bra will not only fail to protect the breasts,but also cause breast damage.Women should choose suitable sports bras according to the breast size,shape and exercise types.The protective effect and comfort of the sports bras have become an important indicator for consumers to purchase sports bras.This topic compares the differences in the breast displacement law in different relative displacement coordinate systems,and provides a guarantee for the selection of the relative displacement coordinate system for subsequent experiments to ensure the accuracy of the results.Use the Opti Track motion capture system to simultaneously record the points on the breasts(left nipple point,4cm inside the breast level,4cm outside the breast level,4cm vertical under the breast,and above the breast when the subject is performing leg-raising exercises on the trampoline.The displacement data of the side vertical 4cm),using the displacement,speed,and acceleration of the breast during exercise as the evaluation criteria,and comparing the protective effects of sports bras with different back structures and different fabrics on the breasts,and obtaining a better protection of the back structure And fabric composition.At the same time,the correlation analysis between relative displacement,relative velocity,relative acceleration and subjective comfort evaluation results is carried out to explore the relationship between breast kinematics parameters and comfort,and provides different research angles for comfort.The research of this subject shows that:(1)The relative displacement system is established at 3 points,including the upper notch of the sternum angle,the lower edge of the left costal arch and the lower edge of the right costal arch.The displacement data of each point of the breast is more accurate,which conforms to the geodetic coordinate system.(2)The displacement and speed of the breast in different directions are vertical>mediolateral>anteroposterior,and the acceleration is in the order of anteroposterior >mediolateral>vertical.The laws of displacement and velocity are inconsistent.Combined with the subjective comfort evaluation results,using Spearman analysis,it is found that breast comfort has no correlation with acceleration,but with displacement and velocity,and the correlation with speed is slightly greater than that of displacement,mainly related to vertical,mediolateral displacement and velocity;(3)Different styles of sports bras have a positive effect on breast displacement and velocity has a significant effect,but has no significant effect on acceleration.The sports comfort is I-shaped>Xshaped>T-shaped>one piece;compared with the sports bra without zipper in the front center,although it is convenient to put on and take off,sports comfort is slightly worse;(4)The higher the content of spandex in the sports bra fabric,the greater the elasticity of the fabric,the poorer the displacement of the breast vibration,the greater the speed and the acceleration during exercise,and the weaker the breast protection effect.