An investigation into the within and between participant variance in three-dimentional breast kinematic data during a 5 km run

The purpose of this study was to examine the within and between participant coefficient of variance (%CV) in three-dimensional (3D) breast kinematic data during a 5 km run. Participants (n=9) performed a 5 km treadmill run in two levels of breast support (low and high) and an additional two minute treadmill run without breast support. A significant increase in within participant %CV for vertical breast displacement and velocity at the second kilometre of the 5 km run, was found when breast support was increased from a low to high level. Peak between participant %CV was found in the low level breast support and reported to be greater than 50% for 3D breast kinematics. This study is the first to report within and between participant variance in 3D breast kinematic data during prolonged running and will inform future research within this area.