Recurrence quantification analysis to assess structure of breast motion variability for jumping jacks exercise

Prior observations and qualitative descriptions of breast motion suggest that structure of motion variability may be important for understanding how breasts move and how support from bras alters breast and body motion. The purpose of this study was to demonstrate the feasibility of utilising recurrence quantification analysis (RQA) to measure nonlinear properties of breast, thorax and upper-arm motion variability for different breast support levels and breast sizes. Support from bras causes breast motion which is less deterministic and therefore less predictable. Motion of larger breasts is less random and more complex, but these nonlinear aspects of motion, unlike amplitude, are not as dependent on size. These findings increase understanding of the structure of breast and body motion variability and how bras influence the motions. Such information may improve bra design with the goal of allowing more effective human performance of work and exercise.