Estimating non-linear strains in the breast during exercise

The static and dynamic strain of the breast mass of four participants were measured while standing and running using a five-camera passive marker system running at 200 Hz. When stationary, the static downward strain of the breast increased with breast size and decreased with use of an everyday bra. Plots of force-strain on the breast mass during motion showed a clear non-linearities above 40% strain in agreement with previous studies on skin and tissue. The peak forces during motion increased with breast mass and were reduced by the wearing of a bra, and in particular a sports bra. The relationship between bra condition and peak strain during motion was less clear.