Traditional breast displacement studies included human subjects and maintaining result consistency is restricted by biomechanical limitations. This study proposes an objective approach that investigates the effects of various bra features on breast support during movement by conducting a wear trial with the VICON motion capture system. The vertical breast displacement in five different bra conditions is assessed and compared. Results indicate that the effectiveness of bras depends on the cup material used and design. The foam cups which are low in density and fabricated from soft polyurethane induces less overall breast displacement during movement. Bras of full-cup style also offer better breast movement control with significant vertical breast displacement reduction as compared with the half-cup style. These findings enhance current breast displacement analysis and understanding of bra features associated with changes in the biomechanics of breasts, thereby providing objective methods for bra evaluation and a design basis for breast protection.