Bra–breast forces generated in women with large breasts while standing and during treadmill running: Implications for sports bra design

This study aimed to determine the bra–breast forces generated in women with large breasts while these women wore different levels of breast support during both upright standing and treadmill running. The mean bilateral vertical component of the bra–breast force in standing was 11.7 ± 4.6 N, whereas during treadmill running the mean unilateral bra–breast force was 8.7 ± 6.4 N and 14.7 ± 10.3 N in the high and low support conditions, respectively. Furthermore, breast mass was significantly correlated with vertical breast displacement (R2 = 0.62) in the high support condition. The wide range of breast masses of women with large breasts is an important consideration for designers of sports bras to ensure these bras can reduce force generation and breast discomfort by providing a high level of breast support while these women participate in physical activity. ► Breast movement and discomfort are barriers to exercise for women with large breasts. ► Women with large breasts have a wide range of breast volumes (283–1345 ml). ► High support sports bras significantly decrease bra–breast force. ► Breast mass and force are important biomechanical considerations for bra design.