Comparison of breast motion at different levels of support during physical activity

Abstract

Optical tracking systems have been used in previous studies to capture the motion of the nude breast and breasts in bras, under the assumption that no breast-bra relative movement occurred within the bra. This study compared breast and bra movement through electromagnetic tracking and optical tracking systems to determine the relative breast movement occurring with different breast support and exercise-induced breast discomfort. Total of 30 female participants (mean age: 21.5 ± 2.3 years; cup sizes: A-F) were recruited and their movement at four different levels of breast support was recorded in two motion capture systems for further analysis and comparison. Significant differences between bra and breast vertical displacement were found at all support levels during periods of intense movement (r = 0.556; p < 0.05). Because the greatest bra displacement was observed when participants wore an everyday bra and the greatest breast displacement was observed when participants wore a crop-top bra, there was evident inconsistency in bra and breast motion and a high-impact sports bra was the most effective to reduce breast movement and discomfort among the four types of bras. An electromagnetic tracking system provided direct observation of the actual movement of the breasts, and an optical tracking system enabled us to monitor bra displacement. Significant differences were observed in bra and breast displacement during the intense movements included in this study. The results bring into question the assumption made in previous studies that no relative movement occurs within a breast support garment.

Breast Biomechanics: What Do We Really Know?

“…Numerous biomechanical studies have since confirmed this sinusoidal breast movement pattern, with greater breast displacement found with increased breast mass, vertical torso motion, and lower limb cadence (22,86,97,142,144,164). Conversely, less breast displacement was found when women wore increased external breast support, usually provided by a sports bra (22,51,77,82,84,89,101,116,120,133,143,160,164,166,175,176). Graphs of three-dimensional breast displacement during treadmill running, when women ran with and without breast support, are displayed in Scurr et al (144).…”

“…Numerous studies have investigated the effects of different breast support conditions on breast motion (22,25,51,58,77,82,84,89,101,105,116,120,132,133,143,160,163,164,166,176,177). These studies have consistently shown that breasts move more when a woman is not wearing any external breast support (bare-breasted) compared with wearing either low external breast support (such as a fashion bra) or high external breast support (such as a sports bra).…”

“…Furthermore, no published research was located that compared the magnitude of breast movement displayed by older women and younger women with the same breast volume. Although the magnitude of breast movement has been reported to increase with breast size, only a few of the published studies have included women with bra sizes equivalent to a DD cup or larger (15,89,101,107,108,160,166). This is despite bra cup sizes ranging from A up to a size I cup (147), whereby 37% of the female population have large or hypertrophic breasts (27).…”

“…Furthermore, most studies have investigated breast motion during walking or running. Less than a quarter of published studies have examined breast motion during other exercise modalities, such as aquatic-based activities (97,106,107), jumping (15,25,84,86,106,116,132,160), and upper limb movements (160). Further research is therefore required to investigate breast motion of more women, particularly those who are older, have larger breasts, and represent the body mass index of the broader female population.…”

Comparative study of moisture adaptable breast support using engineered fabric design in seamless knitted sports bras

“…Another way of controlling breast displacement is via encapsulation sports bras that separate each breast in designed cups, often with the use of under-wires that lead to a loss of comfort while exercising (Norris et al , 2021). A hybrid-type sports bra design, which combines both compression and encapsulation feature, provides breast elevation and compression at the same time, and has been shown to reduce breast displacement and breast discomfort more efficiently (McGhee et al , 2013; Ching-Sui et al , 2017).…”