Methods of studying breast motion in sports bras: a review

There is exponentially increasing number of research publications studying breast motion in sports bras. However, there are large varieties of their methods and findings. To critically evaluate the consistency and limitations of previous breast motion studies, a systematic review of all articles on breast motion in sports bras was performed. A total of 17 fully extracted studies included 216 subjects, aged from 20 to 60 with bra cup sizes from A to J. They participated in only four types of activities with or without bras, but not in randomized controlled trials. Most studies focused on the vertical nipple movements, but seldom examined the three-dimensional breast velocity, acceleration, and trajectory. The sample sizes and the types of activities were limited. The reference frames were not stable in most studies. To study the realistic breast movements in the future, a standardized local coordinate system will be needed.