Abstract: To study the effects of breast displacement on comfort, the To study the effects of breast displacement on comfort, the experimental procedure was designed. The subject was filmed by VICON motion analyzer while ran on the treadmill at 5 km/h and 10 km/h in bare breasted, 3/4 cup size bra and sports bra condition. Subjective data was collected immediately after the treadmill running trials. And from the result we obtained that running speed had positive correlation with breast displacement; breast displacement had negative correlation with comfort, amplitude of vertical breast displacement was the main factor affecting comfort; the sports bra provided limited vertical breast displacement and pain reduction. This research provided an available approach for studying the bra.

Key words: breast displacement, comfort, sports bra, 3/4 cup size bra, correlation analysis