Control Performance of Different Bra Designs and Materials during Physical Activity

Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong

Abstract

Bras give support to the breasts and prevent damage to their different components during daily activities. Previous studies have however merely focused on specific types of bras and/or shoulder straps but failed to provide specific guidelines on bra features and materials that can be used to improve the support different functions of bras. The purpose of this study is to evaluate the breast control performance of various types and designs of bra under the conditions of walking and running. Two younger women and 1 older woman (all with a bra size of 36C/80C) have participated in a wear trial to don a total of 12 different commercial bras with different design features, and a changeable bra in which 12 different variables are examined, including the materials, strap width and type of underwire. The 3D movement of the breasts in the various bra conditions during walking at a speed of 4 km/h and running at 6 km/h is recorded and then compared with the braless condition by using an 11-camera motion capture system. The percentage of change in the nipple displacement in the vertical direction relative to the clavicle displacement is used to quantify and compare the breast control performance of the bras. A significant difference (p<0.01) in the ability of the bras to control movement is observed between the group of younger subjects and the mature subject (left breast: 11.49% vs. 35.42%, and right breast: 18% vs. 32.47%, respectively). The control performance of the bras is significantly different (p<0.01) during running and walking (left breast: 26.39% vs. 12.54%, and right breast: 30.04% vs. 15.61%, respectively). The correlation analysis showed that a small bra cup volume (length across the bra cup), taller gore, elongation of the bra strap and bra band, and rigid bra cup fabric allow good control of vertical breast displacement.