Optimising breast support in female patients through correct bra fit. A cross-sectional study

Spinal joint moment prediction following simulated breast surgery using a female whole-body musculoskeletal model

This study aimed to use a musculoskeletal model to predict changes in spinal moments following simulated breast surgery. A female full body musculoskeletal model with a fully articulated thoracolumbar spine and independent moveable breast segments was customised for this study. Key findings suggest that the simulated removal of breast tissue (750 g to 1501 g) can reduce the magnitude of lumbar spine extensor moments by >0.05 Nm/kg during walking and jogging. A customised female whole-body musculoskeletal model is capable of providing a first approximation of changes in spinal loading following simulated breast surgery.

Sports Bra Restriction on Respiratory Mechanics during Exercise

PURPOSE

We set out to understand how underband tightness or pressure of a sports bra relates to respiratory function and the mechanical work of breathing ( during exercise. Our secondary purpose was to quantify the effects of underband pressure on O 2 during submaximal running.

METHODS

Nine highly trained female runners with normal pulmonary function completed maximal and submaximal running in three levels of underband restriction: loose, self-selected, and tight.

RESULTS

During maximal exercise, we observed a significantly greater during the tight condition (350 ± 78 J·min -1 ) compared with the loose condition (301 ± 78 J·min -1 ; P < 0.05), and a 5% increase in minute ventilation ( ) during the tight condition compared with the loose condition ( P < 0.05). The pattern of breathing also differed between the two conditions; the greater maximal during the tight condition was achieved by a higher breathing frequency (57 ± 6 vs. 52 ± 7 breaths·min -1 ; P < 0.05), despite tidal volume being significantly lower in the tight condition compared with the loose condition (1.97 ± 0.20 vs. 2.05 ± 0.23 L; P < 0.05). During steady-state submaximal running, O 2 increased 1.3 ± 1.1% (range: -0.3 to 3.2%, P < 0.05) in the tight condition compared with the loose condition.

CONCLUSIONS

Respiratory function may become compromised by the pressure exerted by the underband of a sports bra when women self-select their bra size. In the current study, loosening the underband pressure resulted in a decreased work of breathing, changed the ventilatory breathing pattern to deeper, less frequent breaths, and decreased submaximal oxygen uptake (improved running economy). Our findings suggest sports bra underbands can impair breathing mechanics during exercise and influence whole-body metabolic rate.

Hidden support for the lionesses: a breast/bra intervention

Despite health and performance benefits of appropriate breast support in sport, elite women athletes' knowledge of breasts/bras is poor leading to poor bra choices, breast pain and performance decrements. This multiphase intervention assessed breast/bra issues and preferences, individually prescribed sports bras and evaluated outcomes for the England Senior Women footballers. Breast/bra workshops were delivered to England players; all 36 completed pre-intervention surveys and breast/bra assessments, before being prescribed bras six weeks before European and World Championships (2022, 2023). 24 players completed post-intervention surveys. Pre-intervention outcomes identified poor knowledge, poor bra fit, many bra issues, and cultural sensitivities. Breast pain was prevalent (61%), with 25% reporting clinically significant breast pain. Post-intervention, players reported significant improvements with prescribed sports bras. 91% reported improvements in knowledge and benefiting from the intervention. This successful intervention provided an evidence-base for ongoing breast health initiatives with England Teams, plus roll-out to all levels of women's football.

Does an alternative breast support garment provide symptomatic relief for larger breasted women with chronic non-specific back pain?

BACKGROUND

Nonsurgical guidelines recommend implementing a correctly fitted bra when managing back pain among larger breasted women. Achieving this is challenging with current bra solutions, sizing principles, and fitting approaches. Persistent wearing of an ill-fitting bra can cause negative health implications, including non-specific back pain.

OBJECTIVES

This study investigated immediate and short-term biomechanical and pain responses to changing breast support garment among larger breasted women with non-specific back pain.

METHODS

Participants (n = 24) performed a standing task, drop jumps, and seated typing tasks while bra and spinal kinematic data were recorded. Five breast support conditions were assessed: participants' usual bra (control), a professionally fitted bra in the immediate term (standard) and after 4 weeks wear (standard28), and a bra with an alternative design, measurement, and fitting approach in both the immediate term (alternative) and after 4 weeks wear (alternative28). A bra fit assessment and clinical pain/disability questionnaires were included.

RESULTS

All participants failed the bra fit assessment in the control bra, compared with 87.5% (n = 21) in the standard and 4.2% (n = 1) in the alternative bras. The standard28 and alternative28 bras provided symptomatic relief, with the alternative28 bra improving a greater number of outcome measures. Reduced nipple-sternal-notch distance was observed only in the alternative28 bra condition.

CONCLUSIONS

Symptomatic relief may be associated with the resting position of the breast tissue on the anterior chest wall. The alternative bra may provide potential clinical benefit if implemented as part of a nonsurgical or conservative pain management strategy. Alternative breast support garments should be considered to provide solutions to the problems associated with traditional bras.

Ultra-dense Motion Capture: An exploratory full-automatic approach for dense tracking of breast motion in 4D

Understanding the dynamic deformation pattern and biomechanical properties of breasts is crucial in various fields, including designing ergonomic bras and customized prostheses, as well as in clinical practice. Previous studies have recorded and analyzed the dynamic behaviors of the breast surface using 4D scanning, which provides a sequence of 3D meshes during movement with high spatial and temporal resolutions. However, these studies are limited by the lack of robust and automated data processing methods which result in limited data coverage or error-prone analysis results. To address this issue, we identify revealing inter-frame dense correspondence as the core challenge towards conducting reliable and consistent analysis of the 4D scanning data. We proposed a fully-automatic approach named Ulta-dense Motion Capture (UdMC) using Thin-plate Spline (TPS) to augment the sparse landmarks recorded via motion capture (MoCap) as initial dense correspondence and then rectified it with a sophisticated post-alignment scheme. Two downstream tasks are demonstrated to validate its applicability: virtual landmark tracking and deformation intensity analysis. For evaluation, a dynamic 4D human breast anthropometric dataset DynaBreastLite was constructed. The results show that our approach can robustly capture the dynamic deformation characteristics of the breast surfaces, significantly outperforms baselines adapted from previous works in terms of accuracy, consistency, and efficiency. For 10 fps dataset, average error of 0.25 cm on control-landmarks and 0.33 cm on non-control (arbitrary) landmarks were achieved, with 17-70 times faster computation time. Evaluation was also carried out on 60 fps and 120 fps datasets, with consistent and large performance gaining being observed. The proposed method may contribute to advancing research in breast anthropometry, biomechanics, and ergonomics by enabling more accurate tracking of the breast surface deformation patterns and dynamic characteristics.

Increasing Breast Support is Associated With a Distal-to-Proximal Redistribution of Joint Negative Work During a Double-Limb Landing Task

Female athletes exhibit greater rates of anterior cruciate ligament injury compared with male athletes. Biomechanical factors are suggested to contribute to sex differences in injury rates. No previous investigation has evaluated the role of breast support on landing biomechanics. This study investigates the effect of breast support on joint negative work and joint contributions to total negative work during landing. Thirty-five female athletes performed 5 landing trials in 3 breast support conditions. Lower-extremity joint negative work and relative joint contributions to total negative work were calculated. Univariate analyses of variance were used to determine the effect of breast support on negative joint work values. Increasing levels of breast support were associated with lower ankle negative work (P < .001) and ankle relative contributions (P < .001) and increases in hip negative work (P = .008) and hip relative contributions (P < .001). No changes were observed in total negative work (P = .759), knee negative work (P = .059), or knee contributions to negative work (P = .094). These data demonstrate that the level of breast support affects lower-extremity biomechanics. The distal-to-proximal shift in negative joint work and relative joint contributions may be indicative of a more protective landing strategy for anterior cruciate ligament injuries.

Impact of autologous breast reconstruction on bra fit

PURPOSE

To inform bra design by analyzing 3D surface images of breast cancer patients who underwent autologous breast reconstruction.

METHODS

We computed bra design measurements on 3D surface images of patients who underwent unilateral and bilateral autologous breast reconstruction. Breast measurements and right-left symmetry between preoperative baseline and postoperative time points were compared using either paired Student t-test or Wilcoxon signed-rank test, depending on the data's distribution. Regression analysis determined associations between measurements and patient characteristics such as age. Postoperative measurements and symmetry differences were also compared between autologous and implant-based breast reconstruction.

RESULTS

Among participants who underwent bilateral autologous breast reconstruction, the reconstructed breasts were smaller and positioned higher on the chest wall than their native breasts. For patients who underwent unilateral reconstruction, similar postoperative changes were observed in the contralateral breast due to symmetry procedures. Overall, for participants whose baseline breast measurements showed substantial asymmetry, unilateral reconstruction decreased right-left asymmetry whereas bilateral reconstruction amplified right-left asymmetry. Preoperative baseline breast measurements, age, and BMI were statistically significantly associated with most postoperative breast measurements for participants who underwent bilateral autologous reconstruction. Compared to implant-based reconstruction, autologous reconstruction resulted in fewer changes in breast shape and symmetry that are pertinent to bra fit.

CONCLUSION

Preoperative baseline breast measurements, age, and BMI can impact bra designs for breast cancer survivors who undergo autologous reconstruction due to size, shape, and symmetry changes. Bra needs of people who undergo autologous reconstruction differ from those who undergo implant-based reconstruction.

Breasts as a perceived barrier to physical activity in Mexican women: A cross-sectional study

BACKGROUND

Scarce evidence exists on barriers to physical activity in Mexican women. Despite evidence from other countries, no research has investigated the influence of the breast on PA in this population.

OBJECTIVE

To determine the association between the breast and physical activity in Mexican women.

DESIGN

Cross-sectional observational study.

METHODS

Volunteers were 279 Mexican women from Veracruz, Durango, and Baja California states, who completed a paper survey of their demographics, brassiere characteristics, breast pain, and frequency and amounts of weekly physical activity.

RESULTS

The first barrier to physical activity was time constraints, followed by breast-related issues. Breast pain was reported by 47.1% of women, and the breast as a barrier to physical activity participation was reported by 30.6%. Responses, such as "I am embarrassed by excessive breast movement" and "My breasts are too big" were the most frequently reported breast-related barriers to physical activity. Breast pain was associated with the menstrual cycle and exercise. Breast health knowledge and pain intensity were unrelated to moderate- and vigorous-intensity physical activity. The 36.4% and 6.7% of women did not meet weekly moderate- and vigorous-intensity physical activity guidelines, respectively. Weekly moderate- and vigorous-intensity physical activity was similar between women reporting breast pain and those who did not.

CONCLUSIONS

Because the breast was the second most significant barrier to physical activity, it is imperative to increase breast health knowledge in Mexican women to reduce impediments to physical activity.

Impact of implant-based breast reconstruction on bra fit

Comfortable and well-fitting bras are necessary for good quality of life but hard to find for women who undergo reconstruction after breast cancer treatment. This study aimed to provide data to inform bra designs for breast cancer survivors. We measured anatomical distances used in bra design on 3D clinical photographs of patients who underwent unilateral and bilateral implant-based reconstruction to quantify changes after reconstruction relative to the measured values before the person underwent surgery. We performed additional assessments of symmetry before surgery and after reconstruction, and we used regression analyses to identify associations between the measurements and patient characteristics, such as BMI. Overall, almost all measurements changed significantly in implant-based reconstructed breasts relative to native breasts. We highlight several aspects of ergonomic bra design that will be impacted by the changes in anatomical distances. Practitioner summary: Implant-based breast reconstruction surgery changes the breast so that off-the-rack bras are inadequate. This study provides designers with measurement data from women who underwent implant-based reconstruction to inform bra designs for this population. The key factor designers need to account for is the semi-spherical shape of the reconstructed breast.

Analysis on the Difference between the Practical Brassiere Size and Real Breast Volume

Background

Brassiere cup size is defined as the difference in chest circumference between the inframammary fold and the fullest part of the breast. However, a large number of women are not aware of the correct definition and are prone to wearing incorrectly-sized brassieres. In this report, the authors compared the cup size of worn brassieres and the actual measurement.

Methods

This study was a retrospective review of patients who had undergone breast reconstruction operation between May 2020 and June 2021. All patients who visited the plastic surgery clinic for breast reconstruction were inquired about their cup size, and their breast circumferences were measured. The patient demographic information, ptosis grade, mastectomy specimen weight, measured breast circumference, and known cup size were analyzed.

Results

Overall, 163 women were included. Notably, 92 of 163 patients (56.4%) were wearing a correctly-sized brassiere. Patients were more likely to wear a correctly-sized brassiere as the cup size became smaller. Moreover, patients with A-cup breasts tended to wear larger brassieres, whereas patients with B and C-cup breasts tended to wear smaller brassieres than their actual breast cup size.

Conclusions

Approximately one in two women do not know their correct brassiere cup size. Women tend to wear a brassiere of the wrong size as their cup size becomes larger. Therefore, it is important for surgeons to be aware of their patient's brassiere wearing habit and their perception when a surgery, such as augmentation or reconstruction, is planned.

Physiology of Health and Performance: Enabling Success of Women in Combat Arms Roles

INTRODUCTION

The modern female soldier has yet to be fully characterized as she steps up to fill new combat roles that have only recently been opened to women. Both U.S. and U.K. military operational research efforts are supporting a science-based evolution of physical training and standards for female warfighters. The increasing representation of women in all military occupations makes it possible to discover and document the limits of female physiological performance.

METHOD

An informal Delphi process was used to synthesize an integrated concept of current military female physiological research priorities and emerging findings using a panel of subject matter experts who presented their research and perspectives during the second Women in Combat Summit hosted by the TriService Nursing Research Program in February 2021.

RESULTS

The physical characteristics of the modern soldier are changing as women train for nontraditional military roles, and they are emerging as stronger and leaner. Capabilities and physique will likely continue to evolve in response to new Army standards and training programs designed around science-based sex-neutral requirements. Strong bones may be a feature of the female pioneers who successfully complete training and secure roles traditionally reserved for men. Injury risk can be reduced by smarter, targeted training and with attention directed to female-specific hormonal status, biomechanics, and musculoskeletal architecture. An "estrogen advantage" appears to metabolically support enhanced mental endurance in physically demanding high-stress field conditions; a healthy estrogen environment is also essential for musculoskeletal health. The performance of female soldiers can be further enhanced by attention to equipment that serves their needs with seemingly simple solutions such as a suitable sports bra and personal protective equipment that accommodates the female anatomy.

CONCLUSIONS

Female physiological limits and performance have yet to be adequately defined as women move into new roles that were previously developed and reserved for men. Emerging evidence indicates much greater physical capacity and physiological resilience than previously postulated.

A multi-stage intervention assessing, advising and customising sports bras for elite female British athletes

Appropriate breast support is recommended in sport; however, what constitutes appropriate support is complex, individual and often sports specific, particularly in elite sport given the wear duration. This intervention educated, assessed and advised elite British female athletes on breasts and bras; those with unresolved issues engaged in bespoke bra interventions. Following educational workshops (n = 80), breast/bra surveys (n = 60), individual bra assessments (n = 37); a rower, shooter, and hockey player participated in the bespoke bra intervention. Eighty-three per cent of athletes rated their breast/bra knowledge as ≤average. Fifty-one per cent experienced breast pain, affecting performance for 29%; seven used medication and one surgery to relieve symptoms. In individual bra assessments most wore ill-fitting, unsupportive bras and wanted bra advice. Bespoke bra interventions eliminated breast pain: for the rower, improved breast position and spine rotation; for the shooter, repositioned tissue and improved performance; and for the hockey player, accommodated smart devices. Whilst bespoke bra development is challenging, most elite athlete breast/bra issues are resolved via education, advice and fitting.

How much error is associated with calculating breast volume from three-dimensional breast scans obtained when women are standing? Implications for bra design and bra fit

BACKGROUND

A lying prone position is recommended when scanning women's breasts to ensure the entire breast can be visualised. However, several large databases contain three-dimensional scans of women's breasts and torsos that were obtained while the women were standing. This study aimed to establish the error associated with calculating breast volume from three-dimensional breast scans taken when women were standing relative to lying prone.

METHODS

Breast volume was derived for 378 women with Small, Medium, Large and Hypertrophic breast sizes from scans taken while the women were standing and then lying prone.

RESULTS

The magnitude of error associated with breast volume derived from scans obtained while women stood compared to lying prone, ranged from ∼8-22% and increased with increasing breast size.

CONCLUSION

Errors associated with breast volume data derived from breast scans collected while women stand must be accounted for, particularly for women with Medium, Large and Hypertrophic breast sizes. Practitioner summary: This original research provides evidence for bra designers and manufacturers on the degree of error associated when using breast scans obtained while women were standing, such as those scans readily available in large scanning databases. These errors increase with increasing breast size and must be accounted for when sizing and designing bra cups.

Does the fit of personal protective equipment affect functional performance? A systematic review across occupational domains

OBJECTIVE

To explore the effect of personal protective equipment (PPE) fit on functional performance across a range of occupational domains.

BACKGROUND

PPE introduces an ergonomic, human systems integration, and mass burden to the wearer, and these factors are thought to be amplified if PPE is ill-fitting. However, few studies have considered the role of fit (static, dynamic, and cognitive) when evaluating PPE-related performance detriments in occupational settings.

METHOD

A systematic literature review was conducted to identify relevant studies, which were then critically appraised based on methodological quality and collated to compare key findings and present evidence-based recommendations for future research directions across a range of occupational domains.

RESULTS

16 published studies met the inclusion criteria, 88% of which found that the fit of PPE had a statistically significant effect on occupational performance. Poorly sized PPE resulted in slower or increased reaction time; decreased range of motion or mobility; decreased endurance or tolerance; decreased pulmonary function; and altered muscle activation. Limited research met the inclusion criteria and those that did had risks of bias in methodology quality.

CONCLUSION

Future research evaluating the effect of PPE on performance in occupational settings should aim to recruit a more representative population; consider sex as a covariate; quantify and evaluate PPE fit and performance when integrated with all relevant equipment items; include outcome measures related to all three categories of fit (static, dynamic, cognitive); and assess performance of operationally relevant tasks.

Sports Bra Pressure: Effect on Body Skin Temperature and Wear Comfort

Sports bras are an essential apparel for active women, but may exert excessive pressure that negatively affects thermoregulation, thermal comfort and wear sensation. This study measures skin temperature changes during short durations of exercise on a treadmill with different bra pressures. The results based on 21 female subjects (age: 27.2 ± 4.5 years old) show that bras with more pressure at the underband or shoulder straps do not cause statistically significant skin temperature changes during exercise (p > 0.05). Nevertheless, compared to the optimal bra fit, significant differences in bra-breast skin temperature are found during running, cooling down and sitting when the bra pressure is increased (p < 0.05), particularly under bra cup (T1) in this study. The FLIR thermal images can visualize the skin temperature changes at abdomen throughout the four activity stages. Subjective sensations of bra thermal comfort, pressure and breast support are assessed. Despite the increased pressure on the shoulders and chest wall, perceptions towards thermal comfort remain unchanged. The perceived pressure comfort and support sensation amongst the 4 bra conditions are comparable. Interestingly, positive sensations of pressure comfort and breast support are perceived with a tight-fitting sports bra during treadmill exercise. High pressures induced by sports bras (>4 kPa) that habitually considered harmful to the human body may not lead to wear discomfort but enhance bra support sensation and a sense of security to the wearers.

Can we predict the neutral breast position using the gravity-loaded breast position, age, anthropometrics and breast composition data?

BACKGROUND

This study aimed to identify the predictor variables which account for neutral breast position variance using a full independent variable dataset (the gravity-loaded breast position, age and anthropometrics, and magnetic resonance imaging breast composition data), and a simplified independent variable dataset (magnetic resonance imaging breast composition data excluded).

METHODS

Breast position (three-dimensional neutral and static gravity-loaded), age, anthropometrics and magnetic resonance imaging breast composition data were collected for 80 females (bra size 32A to 38D). Correlations between the neutral breast position and the gravity-loaded breast position, age, anthropometrics, and magnetic resonance imaging breast composition data were assessed. Multiple linear and multivariate multiple regression models were utilised to predict neutral breast positions, with mean absolute differences and root mean square error comparing observed and predicted neutral breast positions.

FINDINGS

Breast volume was the only breast composition variable to contribute as a predictor of the neutral breast position. While ≥69% of the variance in the anteroposterior and mediolateral neutral breast positions were accounted for utilising the gravity-loaded breast position, multivariate multiple regression modelling resulted in mean absolute differences >5 mm.

INTERPRETATION

Due to the marginal contribution of breast composition data, a full independent variable dataset may be unnecessary for this application. Additionally, the gravity-loaded breast position, age, anthropometrics, and breast composition data do not successfully predict the neutral breast position. Incorporation of the neutral breast position into breast support garments may enhance bra development. However, further identification of variables which predict the neutral breast position is required.

Patient Self-reported Breast Cup Size and Resultant Mastectomy Specimen Weight: Implications for Reconstructive Breast Surgery

Breast cup sizing irregularities exist due to discrepancy between garment manufacturers and patient reported measurements making it difficult to assess true preoperative and definitive postoperative breast cup size. This study aims to evaluate the association between patient self-reported breast cup size and mastectomy specimen weight as a way to determine postreconstruction breast cup size.

METHODS

This is a retrospective study that evaluated patients who underwent bilateral mastectomy at an academic center between 2019-2021. Cup size and mastectomy weight were our only independent and dependent variables, respectively. Covariates that were assessed included chest circumference, surgical oncologist, BMI, race, and age.

RESULTS

243 patients were evaluated as a part of this study who underwent either total-simple (TS; 29), skin-sparing (SS; 146), or nipple-sparing (NS; 68) bilateral mastectomy. There were positively weak correlations using nonparametric correlation analysis for breast cup size to mastectomy weight in patients who underwent TS (r = 0.375; p = 0.004), SS (r = 0.353; p <0.001), and NS (r = 0.246; p = 0.004) mastectomy. The multivariate linear regression for TS (R₂=0.520; p < 0.001), SS (R₂=0.573; p < 0.001) and NS (R2=0.396; p < 0.001) mastectomy were significant. Covariates assessed in the regression showed BMI significant for all types, age for TS type, and SS type for breast surgeon and chest circumference.

CONCLUSIONS

There is a positively weak correlation between preoperative breast cup size and mastectomy weight, providing evidence for the difficulty of estimating postoperative breast cup size. Thus, the conversation with the patient should focus on breast appearance and quality of life rather than postreconstruction breast size.

Greater Breast Support Is Associated With Reduced Oxygen Consumption and Greater Running Economy During a Treadmill Running Task

Introduction

Breast pain is a major barrier to running for women. While breast support through the use of sports bras reduces breast-related discomfort, the effect of breast support on running performance is less understood. Therefore, the purpose of the current study was to evaluate the effect of greater breast support on oxygen consumption and running economy during a treadmill running task.

Methods

Fifteen female recreational runners performed a 10-min treadmill running task at their preferred running speed in each of two sports bra conditions: low support and high support. Participants ran on an instrumented treadmill (1,200 Hz, Bertec) while indirect calorimetry was performed using a metabolic measurement system (100 Hz, TrueOne, ParvoMedics). Average VO₂ (absolute and relative) from the third to 10th minutes was used to evaluate oxygen consumption. Running economy was calculated as the distance traveled per liter of oxygen consumed. Paired samples t-tests were used to compare mean oxygen consumption and running economy values between breast support conditions. Correlation analysis was performed to evaluate the relationship between breast size and change in running performance.

Results

Greater breast support was associated with reductions in absolute (p < 0.001) and relative oxygen consumption (p < 0.001; LOW: 30.9 ± 7.1 ml/kg/min; HIGH: 28.7 ± 6.7 ml/kg/min). Greater breast support was associated with increases in running economy (p < 0.001; LOW: 88.6 ± 29.1 m/L O₂; HIGH: 95.2 ± 31.1 m/L O₂). No changes in temporospatial characteristics of running were observed including cadence (p = 0.149), step length (p = 0.300) or ground contact time (p = 0.151). Strong positive linear correlations were observed between the change in running performance metrics and breast size (Oxygen Consumption: p < 0.001, r = 0.770; Relative Oxygen Consumption: p < 0.001, r = 0769; Running Economy: p < 0.001, r = 0.807).

Conclusions

Greater breast support was associated with reduced oxygen consumption and increased running economy. These findings demonstrate that greater breast support is not only associated with improved comfort but also improved running performance.

Greater Breast Support Alters Trunk and Knee Joint Biomechanics Commonly Associated With Anterior Cruciate Ligament Injury

Objective

The female breast is a passive tissue with little intrinsic support. Therefore, women rely on external breast support (sports bras) to control breast motion during athletic tasks. Research has demonstrated that lower levels of breast support are associated with altered trunk and pelvis movement patterns during running, a common athletic task. However, no previous study has identified the effect of sports bra support on movement patterns during other athletic tasks including landing. Therefore, the purpose of this study was to examine the effects of breast support on trunk and knee joint biomechanics in female collegiate athletes during a double-leg landing task.

Methods

Fourteen female collegiate athletes completed five double-leg landing trials in each of three different sports bra conditions: no support, low support, and high support. A 10-camera motion capture system (250 Hz, Qualisys, Goteburg, Sweden) and two force platforms (1,250 Hz, AMTI, Watertown, MA, USA) were used to collect three-dimensional kinematics and ground reaction forces simultaneously. Visual 3D was used to calculate trunk segment and knee joint angles and moments. Custom software (MATLAB 2021a) was used to determine discrete values of dependent variables including vertical breast displacement, knee joint and trunk segment angles at initial contact and 100 ms post-initial contact, and peak knee joint moments. A repeated measures analysis of covariance with post-hoc paired samples t-tests were used to evaluate the effect of breast support on landing biomechanics.

Results

Increasing levels of breast support were associated with reductions in peak knee flexion (Right: p = 0.008; Left: p = 0.029) and peak knee valgus angles (Right: p = 0.011; Left: p = 0.003) as well as reductions in peak knee valgus moments (Right: p = 0.033; Left: p = 0.013). There were no changes in peak knee extension moments (Right: p = 0.216; Left: p = 0.261). Increasing levels of breast support were associated with greater trunk flexion angles at initial contact (p = 0.024) and greater peak trunk flexion angles (p = 0.002).

Conclusions

Lower levels of breast support are associated with knee joint and trunk biomechanical profiles suggested to increase ACL injury risk.

The impact of breast support garments on fit, support and posture of larger breasted women

Due to current measurement, sizing and fitting approaches, poor bra fit is prevalent amongst larger breasted women. The impact of improving bra fit hasn't yet been explored. This pre-clinical study aimed to explore immediate and short-term biomechanical responses to changing breast support garment. Asymptomatic participants (n=24) performed a static standing task, drop jumps and seated typing whilst kinematic data from the breasts and spine were recorded. Three breast support conditions were assessed: Usual, professionally fitted bra in the immediate term (PFB), and the same professionally fitted bra after four weeks wear (PFB₂₈). Bra fit assessments were included for both bras. All participants failed the bra fit assessment when wearing the Usual bra and 67% (n=16) failed when wearing the PFB. Less bra fit issues were present in the PFB, resulting in immediate biomechanical changes relating to breast support and spinal posture, yet nothing in the short term (PFB₂₈). This research sets the foundations for future work to investigate whether the implementation of better fitting breast support garments can influence musculoskeletal pain amongst larger breasted women, whilst attributing potential improvement of symptoms, objective measures of breast support and spinal posture.

Effect of Torso and Breast Characteristics on the Perceived Fit of Body Armour Systems Among Female Soldiers: Implications for Body Armour Sizing and Design

This study aimed to provide normative data characterising the torsos and breasts of female soldiers and to determine which torso and breast anthropometric measurements contributed to reports of poor body armour fit. Ninety-seven female Australian Army soldiers completed a questionnaire about their experience with current-issue body armour, including perceptions of fit. Participants also attended a single testing session where we took a three-dimensional scan of their breasts and torso and collected several anthropometric measurements to characterise their torso size and shape. Sixteen of the 22 breast and torso measurements collected were significantly related to the perceived fit of current-issue body armour systems. To improve perceptions of fit for female soldiers and, in turn, reduce movement interference, discomfort, and barriers to occupational performance, future body armour systems should cater to the wide range of female breast and torso shapes and sizes.

The effect of washing and wearing on sports bra function

Sports bras provide support by restricting breast motion during exercise, which may prevent damage to breast structures. Laundering affects the mechanical properties of some sports bra materials. Bra function on the wearer after washing is unreported, meaning sports bra durability is unknown. This intervention study compared subjective and objective performance of sports bras that were washed, and worn/washed, to a control. Twenty-two females were assigned three identical sports bras; control, washed and worn/washed (washed after 60-min wear). Pre-intervention: breast position was recorded while standing and running in each bra. Comfort, fit and aesthetics were rated. Intervention: participants undertook their normal exercise in their worn/washed bra. Post-intervention: after 25 washes (n = 19), pre-intervention testing was repeated. Breast volume and control bra motion were consistent pre/post-intervention; however, post-intervention breast motion increased (20% mediolaterally, 16% superioinferiorly) in washed bras and (32% mediolaterally, 25% superioinferiorly) worn/washed bras. Post-intervention washed, and worn/washed bras were perceived as less supportive and washed bras less comfortable than worn/washed bras. Sports bra support reduced after 25 washes; this was compounded by wear. Participants detected reduced support, but comfort was sustained, suggesting replacement may not be considered. Guidelines on sports bra durability are recommended for breast health.

Optimizing Health and Athletic Performance for Women

PURPOSE OF REVIEW

The exponential growth of women participating in competitive sports throughout the years was made possible through several initiatives by the International Olympic Committee and the passage and implementation of Title IX as a federal law in the United States. However, this positive trend towards gender equity in sports has not transpired for women in medicine, especially in fields that care for elite athletes. This current review will discuss specific areas that can be tailored to help female athletes prevent injuries and optimize their athletic performance. We will also highlight how increased female team physician representation in sports may help optimize care for female athletes.

RECENT FINDINGS

Female athletes are considered high risk for certain conditions such as ACL tears, patellofemoral pain syndrome, bone stress injuries, sport-related concussions, and sexual violence in sport. Addressing factors specific to female athletes has been found to be valuable in preventing injuries. Strength and conditioning can optimize athletic performance but remains underutilized among female athletes. Although diversity in healthcare workforce has been found to be beneficial for multiple reasons, women remain underrepresented in sports medicine. Increasing female team physician representation may positively impact care for female athletes. Team physicians must understand the physiologic, biomechanical, and anatomic factors that are unique to female athletes in order to tailor injury prevention programs and optimize their athletic performance. Advocating for gender equity in sports medicine to advance representation of women in the field will increase workforce diversity and promote excellence in sports medicine care.

Women with larger breasts are less satisfied with their breasts: Implications for quality of life and physical activity participation

Introduction:

Although low breast satisfaction has been associated with a range of potential negative health implications, little is known about key factors that influence breast satisfaction across the lifespan. This study aimed to determine the impacts of age, body mass and breast size on breast satisfaction and how breast satisfaction impacts psychosocial and sexual well-being-related quality of life outcomes and physical activity behaviours.

Methods:

Three hundred and forty-five women (age range: 18.1–83.7 years) had their body mass (kg), standing height (cm) and breast volume (ml) measured. A 13-item questionnaire comprising the Breast-Q and Active Australia Survey was used to assess breast satisfaction, quality of life outcomes and participation in physical activity.

Results:

Breast satisfaction was influenced by breast size, such that women with larger breasts were less satisfied with their breasts compared to their counterparts with smaller breasts. Greater breast satisfaction was associated with improved psychosocial and sexual well-being-related measures of quality of life, and time spent participating in physical activity.

Conclusion:

Interventions to improve breast satisfaction among women across the breast size spectrum should be encouraged in public health initiatives to better engage and encourage positive health behaviours and reduce potential adverse health implications.

Sports Bra Preferences by Age and Impact of Breast Size on Physical Activity among American Females

For many females, sports bras are an essential piece of equipment for participation in sports and physical activity. Breast pain or discomfort from lack of support may be a contributing factor to the noted gender disparity in physical activity of females compared to males. Our objective was to evaluate sports bra usage and characterize sports bra preferences of an active female cohort. This multicenter cross-sectional survey study was conducted at five geographically distinct academic centers. Our measure was administered during outpatient sports medicine clinic visits to females aged 11–64 years old. Chi-square tests were used to compare characteristics across subgroups. Our analysis consisted of 438 respondents, with a mean age of 22 ± 12.2 years. More than a quarter (27.4%) reported lack of breast support prevented them from being active or exercising. Age (p = 0.03), breast size (p < 0.0001), and household income (p = 0.01) were significantly associated with greater frequency of physical activity being limited by lack of breast support. Lack of breast support may be an important barrier for young females of specific populations to meeting physical activity recommendations. Further research is needed to improve the understanding of this important piece of sporting equipment for women.

Bra-body armour integration, breast discomfort and breast injury associated with wearing body armour

This study investigated whether female soldiers experience bra integration or breast discomfort/injuries related to body armour use and whether these issues were associated with breast size. Ninety-seven Australian Defence Force female soldiers completed a questionnaire and had their breast volume assessed (range: 91-919 ml/breast) using three-dimensional scanning. Twenty-two percent (n = 21) of participants reported integration issues between their bra and body armour, 63% (n = 61) reported breast discomfort while wearing body armour and 27% (n = 26) reported experiencing a breast injury related to wearing body armour. Although bra-body armour integration was not dependent upon breast size, female soldiers with medium-large breasts reported significantly more breast discomfort and injuries when using body armour compared to participants with small breasts. These findings highlight the importance of developing body armour systems that cater to the range of breast sizes of female soldiers in order to improve bra-body armour integration and reduce breast discomfort and injury. Practitioner summary: This exploratory research provides evidence of bra integration issues, breast discomfort and breast injury experienced by female soldiers when wearing body armour. Given the growing representation of women in military organisations, strategies to alleviate these issues for female users of body armour, particularly those with larger breast sizes, are required.

Can Physical Characteristics and Sports Bra Use Predict Exercise-Induced Breast Pain in Elite Female Athletes?

OBJECTIVE

To evaluate whether a simple 4-factor model using self-reported data could be used to predict exercise-induced breast pain in elite female athletes.

DESIGN

Survey study.

SETTING

Online or hard-copy surveys completed at sporting competitions and training facilities around Australia.

PARTICIPANTS

Four hundred ninety female athletes competing nationally or internationally across 49 sports.

INDEPENDENT VARIABLES

A binomial logistic regression analysis was used to evaluate the strength of a predictive model that included 2 continuous independent variables (age and body mass index) and 2 binary independent variables (breast size and sports bra use). Odds ratios were also calculated to determine the likelihood of an athlete reporting exercise-induced breast pain in association with each of the 4 variables.

MAIN OUTCOME MEASURES

Exercise-induced breast pain was the binary dependent variable.

RESULTS

The model incorporating athlete age, breast size, body mass index, and sports bra use was found to be statistically significant, but weak, in its ability to predict exercise-induced breast pain in elite female athletes (correctly identified 66% of athletes). For every 1-year increase in age, a significant 2.6% increase in the likelihood of experiencing exercise-induced breast pain was observed. Athletes with medium-to-hypertrophic sized breasts were 5.5 times more likely to experience exercise-induced breast pain than athletes with small breasts.

CONCLUSIONS

Although the current model was not sensitive enough for use by clinicians and coaches, age and breast size were both identified as critical variables in the prediction of exercise-induced breast pain. Future research is encouraged to investigate whether incorporating additional variables such body fat percentage, bra fit, and other relevant factors can add strength to the model.

The incidence of breast health issues and the efficacy of a sports bra fit and issue service in British Army recruits

Increasing retention of female recruits throughout Basic Training (BT) is a key priority for the British Army. The aims of this study were two-fold; (i) quantify breast health issues and sports bra usage within female British Army recruits, and (ii) assess the influence of professionally fitted sports bras on breast health and bra fit issues across 13 weeks of BT. A survey was completed by 246 female recruits that identified the incidence of breast health issues during BT. Subsequently, 33 female recruits were provided with professionally fitted sports bras during Week-1 of BT. Recruits completed a survey in Week-1 (Pre) and Week-13 (Post). There was a high incidence of bra issues during BT, which did not reduce following the implementation of professionally fitted sports bras. The authors recommend further research into the specific functional requirements of breast support relative to the demands of BT and the needs of the female recruit. Practitioner Summary: The British Army have a duty of care to ensure female recruits are equipped sufficiently for the demands of training. Despite the implementation of a sports bra fitting and issue service bra fit issues remained high. Further research into the specific functional requirements of breast support during training is recommended. Abbreviations: BT: Basic Training; ATR(W): Army Training Regiment Winchester; ATC(P): Army Training Centre Pirbright; BMI: Body Mass Index; NRS: Numeric Rating Scale; FET: Fisher's Exact Test.

How the characteristics of sports bras affect their performance

Breast movement reduction (%) measures breast support and sports bra performance, however limited evidence exists on the sports bra characteristics which affect it. This study investigated breast movement reduction achieved by 98 sports bras, the categorisation of support levels, and the characteristics that contribute. Each bra was tested on ∼12 females (total n = 77). Relative breast position was recorded during sports bra and bare-breasted running, and breast movement reduction calculated; low, medium, high breast support tertiles were identified and compared to brand-classified support levels. Ten bra characteristics were identified, and regressions determined which characteristics contributed to performance. Breast movement reduction ranged from 36% to 74%; 69% of bras marketed as high support were in the high support tertile (>63%). Encapsulation style, padded cups, nylon, adjustable underband and high neck drop accounted for 37.1% of breast movement reduction variance. Findings facilitate high performance sports bra development and inform consumer choice. Practitioner summary: Little is known about the biomechanical breast support which sports bras actually provide. This original research facilitates high performance sports bra development, and helps inform consumer choice, by identifying the breast movement reduction of a large sample of sports bras, and the characteristics which impact sports bra performance. Abbreviations: A-P: anterior-posterior; BMI: body mass index; C7: 7th cervical vertebrae; LNIP: left nipple; M-L: medial-lateral; PX: xiphoid process; ROM: range of motion; S-I: superior-inferior; SD: standard deviation; STN: suprasternal notch; T8: 8th thoracic vertebrae.

Breast Biomechanics: What Do We Really Know?

Although half the world's population will develop breasts, there is limited research documenting breast structure or motion. Understanding breast structure and motion, however, is imperative for numerous applications, such as breast reconstruction, breast modeling to better diagnose and treat breast pathologies, and designing effective sports bras. To be impactful, future breast biomechanics research needs to fill gaps in our knowledge, particularly related to breast composition and density, and to improve methods to accurately measure the complexities of three-dimensional breast motion. These methods should then be used to investigate breast biomechanics while individuals, who represent the full spectrum of women in the population, participate in a broad range of activities of daily living and recreation.

The impact of age and body mass index on a bra sizing system formed by anthropometric measurements of Sichuan Chinese females

Existing bra sizing systems are based only on bust and underbust girths, which do not guarantee an accurate fit or comfort for consumers. This study presents a comprehensive investigation of the impact of age and body mass index (BMI) on bra sizing systems, and the distributions of band and cup sizes based on anthropometric measurement data. The first four principal components were extracted by principal component analysis, and the factor loadings of age and BMI were found to be significant determinants of bra size along with 12 other variables. Furthermore, chi-square analysis revealed that bra size allocations were significantly influenced by age and BMI. Thus, we propose that age and BMI should be considered as auxiliary criteria for the bra sizing system. Taken together, these findings will be of value to designers and bra manufacturers in developing well-fitting bras for their target consumers, and to consumers for selecting well-fitting bras with confidence. Practitioner Summary: This study contributes to an understanding of how bra sizing systems are affected by age and BMI. This understanding is valuable to bra designers, manufacturers, and retailers, as it will enable the adjustment of bra sizes for different target markets and in turn improve consumer confidence in selecting proper fitting and comfortable bras.

Breast Education Improves Adolescent Girls' Breast Knowledge, Attitudes to Breasts and Engagement With Positive Breast Habits

Many females experience breast-related issues that are considered to negatively impact health and well-being. These include breast cancer, issues related to incorrect bra fit, and issues related to breast movement including an increased incidence of breast pain, breast sag, and embarrassment, which can be a barrier to physical activity participation. Knowledge and awareness of these breast issues among females is low. Furthermore, these breast concerns are more prevalent in adolescent girls compared to adult females, with 87% of girls reporting ≥ one breast concern. This study evaluated the short- and longer-term impact of a 50 min breast education intervention on adolescent girls' (11 to 14 years) breast knowledge, attitudes to breasts and engagement with positive breast habits. A mixed methods, controlled, longitudinal, cohort design was employed, using two control schools (n: 412; receiving no intervention) and two intervention schools (n: 375; receiving the intervention) from privileged and less privileged areas. Adolescent girls in four schools completed a validated breast survey pre- and immediately post-intervention as well as 3 and 6 months post-intervention. Additionally, in one intervention school, six focus groups were conducted immediately and 4 months after the intervention. The intervention was equally effective in the two intervention schools. Following the intervention, participants in the intervention schools significantly improved their breast knowledge, their attitudes to breasts and their engagement with positive breast habits, compared to participants in the control schools, p < 0.01 (with large effect sizes). These improvements were sustained 6 months post-intervention. Participants described the session as "informative," it made them "feel less embarrassed" about their breasts; they also reported wanting to do more exercise and to change their bra purchasing and bra wearing habits. These novel, positive findings provide insight into the benefits of teaching adolescent girls about breasts from a young age and can be used to inform effective breast education in schools. It is recommended that education on multiple breast topics should be introduced in schools, preferably being first introduced in primary schools, with a modular structure and progressive information.

Biomechanics of Breast Support for Active Women

More systematic breast biomechanics research and better translation of the research outcomes are necessary to provide information upon which to design better sports bras and to develop effective evidence-based strategies to alleviate exercise-induced breast pain for women who want to participate in physical activity in comfort.

Use and perception of breast protective equipment by female contact football players

OBJECTIVES

Female contact football players sustain contact breast injuries that can negatively affect their sporting performance. This study investigated what female contact football players wear on their breasts during training and competition, and their perceptions on the protection provided by these garments against contact breast injury.

DESIGN

A custom-designed survey about breast injuries and prevention strategies was distributed via an online link to coaches and team staff of contact football teams throughout Australia. The fit and features of breast support and/or protection that players wore during training and competition were also directly assessed.

METHODS

207 female Australian Football League (AFL), Rugby League, Rugby Union (XVs) and Rugby 7s players completed the survey. The breast support of 112 of these players was also assessed.

RESULTS

Only 17% (n=35) of players reported using breast protective equipment, of which 66% (n=23) perceived it provided protection against contact breast injuries. Reasons reported for not using protective equipment included not knowing it existed (n=79, 53%), it was too uncomfortable/hot (n=50, 24%) and that it did not fit or was restrictive (n=33, 22%). Although most players (n=97, 87%) reported to wear a sports bra, 52% (n=58) wore an ill-fitted bra and only 31% (n=63) perceived it provided any protection against contact breast injuries.

CONCLUSIONS

Breast protective equipment is not commonly worn by female contact football players reportedly due to a lack of awareness of its existence, discomfort or poor fit. Although most female contact football players usually wore a sports bra, most players perceived these bras did not provide breast protection.

Validity and Reliability of Three Commercially Available Smart Sports Bras during Treadmill Walking and Running

A variety of wearable technology devices report heart rate. Heart rate sensing smart bras are manufactured for females who participate in activity, however accuracy has not been determined. The purpose was to determine the validity of heart rate measures in three commercially available sports bras during walking and running. Twenty-four healthy females completed bouts of treadmill exercise. The Adidas Smart sports bra, Berlei sports bra, and Sensoria Fitness biometric sports bra were tested. Participant perception of each garment was obtained immediately after the participant divested the sports bra. The Adidas Smart sports bra was valid only during rest (Intraclass correlation Coefficient [ICC] = 0.79, mean absolute percentage error [MAPE] = 4.5%, Limits of Agreement [LoA]=−8 to 8). The Berlei sports bra was valid across all conditions (ICC = 0.99, MAPE = 0.66%, LoA = −19 to 19), and the Sensoria biometric bra was valid during rest and walking (ICC = 0.96, MAPE = 1.9%, LoA = −15 to 12). Perception of the smart sports bras was higher for the Adidas Smart sports bra and Sensoria Fitness sports bra, and lower for the Berlei sports bra. Sports bra manufacturers designing wearable technology garments must consider the ability of returning accurate biometric data while providing necessary function and comfort to females engaging in physical activity.

Undergarment needs after breast cancer surgery: a key survivorship consideration

An important aspect of breast cancer survivorship is finding comfortable undergarments that work for women's post-treatment bodies. Patients who undergo mastectomy, including both those who do and do not receive reconstruction, need bras that can accommodate new breast shape, size, and feel, as well as scarring and skin sensitivity. Our research with breast cancer patients and the literature reveal that ready-to-wear bras are inadequate for the variety of patients' needs, and many women lack support and guidance to make decisions about undergarments after cancer. This commentary describes a major quality-of-life challenge for breast cancer survivors and makes recommendations for future research. Healthcare providers need more guidance and resources to be able to help their patients prepare for this aspect of survivorship. New technologies, such as biomechanical modeling, 3D body scanning, and manufacturing techniques, should be pursued in collaboration with patients, healthcare providers, and clothing designers to ease this burden for breast cancer patients.

Effect of external breast prosthesis mass on bra strap loading and discomfort in women with a unilateral mastectomy

BACKGROUND

A common complaint of women who wear external breast prostheses following mastectomy is that they are too heavy. This study aimed to investigate the effect of external breast prosthesis mass on bra strap loading, discomfort and perceived pressure in women with a unilateral mastectomy.

METHODS

Pressures exerted at the bra strap-shoulder interface and ratings of discomfort and perceived pressure (visual analogue scales; 0-12 cm) were recorded for 17 women (mean 68 (SD 5.7) years) who had a unilateral mastectomy. Data were collected during standing and walking while the women wore a Lightweight prosthesis and Standard-weight prosthesis. Pressure, discomfort and perceived pressure between the two prosthesis conditions were compared using Wilcoxon Signed Ranks and the sum of the pressure values during walking and standing were correlated with discomfort and perceived pressure scores using Spearman's Rho tests.

FINDINGS

Mean peak bra strap pressures were significantly less when the participants wore the Lightweight prosthesis compared to the Control prosthesis during walking (0.28 (SD 0.14) N/cm² versus 0.35 (SD 0.20) N/cm²; P < 0.05) but not during standing. No significant main effect of prosthesis mass on the participants' ratings of discomfort or perceived pressure were found, which were highly variable.

INTERPRETATION

Reducing external breast prosthesis mass decreased mean peak bra strap pressures during walking but this was not accompanied with reductions in bra strap-shoulder discomfort or perceived pressure. Treatment strategies to decrease bra strap-shoulder interface loading due to external breast prostheses mass could assist women who complain of prosthesis heaviness during physical activity.

The relationship between breast size and aspects of health and psychological wellbeing in mature-aged women

OBJECTIVES

Increases in breast size with age are common but have not been widely examined as a factor that could affect the health and psychological wellbeing of mature-aged women. The purpose of this study was to examine the relationships between breast size and aspects of health and psychological wellbeing in mature-aged women.

METHODS

This was a cross-sectional study of mature-aged women (⩾40 years). Breast size (breast size score) was determined from self-reported bra size and was examined against health-related quality of life (Medical Outcomes Study Short-Form 36 and BREAST-Q), body satisfaction (numerical rating scale), breast satisfaction (BREAST-Q), physical activity levels (Human Activity Profile), the presence of upper back pain and breast and bra fit perceptions.

RESULTS

Two hundred sixty-nine women (40-85 years) with bra band sizes ranging from 8 to 26 and bra cup sizes from A to HH participated. The mean (standard deviation) breast size score of 7.7 (2.7) was equivalent to a bra size of 14DD. Increasing breast size was associated with significantly lower breast-related physical wellbeing (p < 0.001, R2 = 0.043) and lower ratings of body (p = 0.002, R2 = 0.024) and breast satisfaction (p < 0.001, R2 = 0.065). Women with larger breasts were more likely to be embarrassed by their breasts (odds ratio: 1.49, 95% confidence interval: 1.31 to 1.70); more likely to desire a change in their breasts (odds ratio: 1.55, 95% confidence interval: 1.37 to 1.75) and less likely to be satisfied with their bra fit (odds ratio: 0.84, 95% confidence interval: 0.76 to 0.92). Breast size in addition to age contributed to explaining upper back pain. For each one-size increase in breast size score, women were 13% more likely to report the presence of upper back pain.

CONCLUSION

Larger breast sizes have a small but significant negative relationship with breast-related physical wellbeing, body and breast satisfaction. Larger breasts are associated with a greater likelihood of upper back pain. Clinicians considering ways to improve the health and psychological wellbeing of mature-aged women should be aware of these relationships.

Upper back pain in postmenopausal women and associated physical characteristics

The physical characteristics of postmenopausal women that are associated with upper back pain are not well-understood. The aim of this cross-sectional study was to identify the physical characteristics associated with presence and severity of upper back pain in healthy postmenopausal women. Self-reported upper back pain presence (within the previous month) and severity (numerical rating scale) were examined against the physical characteristics: height; weight; body mass index; breast size; breast ptosis; upper back extensor muscle endurance (isometric chest raise test); head, shoulder and upper back posture (photogrammetry); thoracic extension mobility (photogrammetry); bone mineral density (dual-energy x-ray absorptiometry (DXA)); body composition (DXA); and thoracic kyphosis, thoracic osteoarthritis and thoracic vertebral fracture (all radiography). A multivariable logistic regression model, adjusted for age, was built using physical characteristics with a significant univariate association with upper back pain. Censored Tobit regression, adjusted for age, was used to examine each physical characteristic against upper back pain severity. Postmenopausal women (n = 119) with a mean (SD) age of 61.4 (7.0) years participated in the study. After adjusting for age, the physical characteristics independently associated with upper back pain were: height (OR: 0.50, 95% CI: 0.31–0.79); and upper back extensor muscle endurance (OR: 0.46, 95%CI: 0.28–0.75). This model explained 31% of the variance in upper back pain (p<0.001). After adjusting for age, being taller and having better upper back extensor muscle endurance were associated with lower odds for upper back pain. After adjusting for age, differences in upper back pain severity were explained by upper back extensor muscle endurance (p = <0.001) and lean mass (p = 0.01). Conclusion: As a modifiable physical characteristic of postmenopausal women with upper back pain, upper back extensor muscle endurance is worth considering clinically.

There are two sides to every story: implications of asymmetry on breast support requirements for sports bra manufacturers

This study aimed to investigate: (1) the prevalence and magnitude of breast movement asymmetry, (2) the interaction between static and dynamic breast asymmetry and (3) the influence of sports bras on breast asymmetry during running. Position data were collected from 167 females whilst treadmill running and then a sub-group of 12 participants in different bra conditions. Breast movement asymmetry existed in 89% of participants, with resultant static breast position asymmetry larger in participants displaying dynamic asymmetry. Asymmetry was most commonly caused (60% to 75%) by greater movement of the left breast. No significant relationships were found between asymmetry and bra size or breast pain. Sports bras reduced asymmetry prevalence from 75% to 33% of participants in the antero-posterior direction but only from 75% to 67% of participants in the infero-superior direction. The magnitude of range-of-motion asymmetry reduced from 67 mm with no bra to between 6 and 64 mm in-bra in the infero-superior direction, with the best performing bra incorporating encapsulating cups and adjustable straps and underband. It is recommended that sports bras allow underband and strap adjustment to facilitate individual breast support and that asymmetry is considered when designing and fitting bras, which could utilise resultant asymmetry measured statically.

Effects of age and body mass index on breast characteristics: a cluster analysis

Limited research has quantified variation in the characteristics of the breasts among women and determined how these breast characteristics are influenced by age and body mass. The aim of this study was to classify the breasts of women in the community into different categories based on comprehensive and objective measurements of the characteristics of their breasts and torsos, and to determine the effect of age and body mass index on the prevalence of these breast categories. Four breast characteristic clusters were identified (X-Large, Very-ptotic & Splayed; Large, Ptotic & Splayed; Medium & Mildly-ptotic; and Small & Non-ptotic), with age and BMI shown to significantly affect the breast characteristic clusters. These results highlight the difference in breast characteristics exhibited among women and how these clusters are affected by age and BMI. The breast characteristic clusters identified in this study could be used as a basis for future bra designs and sizing systems in order to improve bra fit for women. Practitioner summary: This original research provides evidence for bra designers and manufacturers on the diverse breast characteristics exhibited by women within the population and the significant effect that both body mass index and age have on the breast characteristic clusters. Future bra designs should consider the variation in breast characteristics among women.

ABBREVIATIONS

BMI: Body Mass Index; UBCC: Under-bust chest circumference.

Bra band size measurements derived from three-dimensional scans are not accurate in women with large, ptotic breasts

This study investigated differences in standard measurements used to determine bra size, under-bust chest circumference (UBCC) and over-bust chest circumference (OBCC), measured from a three-dimensional scan (hand-held scanner) compared to the direct measurement in 111 women (age 21-56 years; right breast volume 57-1672 mL; bra size 10A-18G). Bland-Altman plots of UBCC measurements showed a large positive bias and wide limits of agreement (12 cm; -4.6 to 28 cm), which increased as band size increased but decreased when the breasts were digitally removed from the scan prior to the UBCC measurement. The difference in UBCC measurements determined from scans compared to direct measurement had a strong positive correlation with breast volume and breast ptotis. The OBCC measurements showed a small positive bias (2.4 cm; -3.4 to 8.4), consistent across the range of bra sizes. Bra band size measurements determined from three-dimensional scans can be inaccurate in women with large, ptotic breasts. Practitioner Summary: We investigated potential errors in anthropometric data derived from three-dimensional scans used for bra design and fit. Bra band size measurements taken from three-dimensional scans were over-estimated in women with large breasts, whereas bra cup size measurements were accurate to within one-cup size across the entire range of bra sizes.

Upper torso pain and musculoskeletal structure and function in women with and without large breasts: A cross sectional study

BACKGROUND

Women with large breasts frequently experience upper torso pain secondary to their breast size. Evidence is lacking on the underlying causes of this pain. This study investigated whether upper torso pain and musculoskeletal structure and function differed between women with large breasts and women with small breasts.

METHODS

A linear regression, adjusting for body mass, compared the upper torso pain, thoracic flexion torque due to breast mass, thoracic kyphosis, shoulder active range-of-motion, and scapular retraction muscle strength of 27 women with large breasts (bilateral breast volume>1200ml, age 45.9y SD 9.9y, BMI 29.0kg/m² SD 3.8kg/m²) and 26 women with small breasts (bilateral breast volume <800ml, age 43.8y SD10.9y, BMI 23.3kg/m² SD 2.9kg/m²).

FINDINGS

Women with large breasts reported a higher upper torso pain score (46.6, 95%CI 33.3-58.0 versus 24.1, 95%CI 12.5-37.8), accompanied by a larger flexion torque (5.9Nm, 95%CI 4.5-5.8Nm versus 0.9Nm, 95%CI 0.8-2.4Nm), greater thoracic kyphosis (34°, 95%CI 31-38° versus 27°, 95% CI 24-31°), decreased shoulder elevation range-of-motion (160°, 95%CI 158-163° versus 169°, 95%CI 166-172°), and decreased scapular retraction endurance-strength (511.4s, 95%CI 362.2-691.3s versus 875.8s, 95%CI 691.5-1028.4s) compared to the women with small breasts.

INTERPRETATION

Differences in the upper torso posture, range-of-motion, and muscle strength of women with large breasts provides insight into underlying causes of their musculoskeletal pain. This information can be used to develop evidence-based assessment and treatment strategies to relieve and prevent symptom progression.

The Bionic Bra: Using electromaterials to sense and modify breast support to enhance active living

BACKGROUND

Although the most supportive sports bras can control breast motion and associated breast pain, they are frequently deemed uncomfortable to wear and, as a result, many women report exercise bra discomfort. Given that exercise bra discomfort is associated with decreased levels of physical activity, there is a pertinent need to develop innovative solutions to address this problem.

OBJECTIVES

This research aimed to evaluate the use of electromaterial sensors and artificial muscle technology to create a bra that was capable of detecting increases in breast motion and then responding with increased breast support to enhance active living.

METHODS

The research involved two phases: (i) evaluating sensors suitable for monitoring and providing feedback on changes in the amplitude and frequency of breast motion, and (ii) evaluating an actuator capable of changing breast support provided by a bra during activity.

RESULTS

When assessed in isolation, the developed technologies were capable of sensing breast motion and actuating to provide some additional breast support.

CONCLUSIONS

The challenge now lies in integrating both technologies into a functional sports bra prototype, and assessing this prototype in a controlled biomechanical analysis to provide a breast support solution that will enable women to enjoy active living in comfort.

Quantification of gravity-induced skin strain across the breast surface

BACKGROUND

Quantification of the magnitude of skin strain in different regions of the breast may help to estimate possible gravity-induced damage whilst also being able to inform the selection of incision locations during breast surgery. The aim of this study was to quantify static skin strain over the breast surface and to estimate the risk of skin damage caused by gravitational loading.

METHODS

Fourteen participants had 21 markers applied to their torso and left breast. The non-gravity breast position was estimated as the mid-point of the breast positions in water and soybean oil (higher and lower density than breast respectively). The static gravity-loaded breast position was also measured. Skin strain was calculated as the percentage extension between adjacent breast markers in the gravity and non-gravity loaded conditions.

FINDINGS

Gravity induced breast deformation caused peak strains ranging from 14 to 75% across participants, with potentially damaging skin strain (>60%) in one participant and skin strains above 30% (skin resistance zone) in a further four participants. These peak strain values all occurred in the longitudinal direction in the upper region of the breast skin. In the latitudinal direction, smaller-breasted participants experienced greater strain on the outer (lateral) breast regions and less strain on the inner (medial) breast regions, a trend which was reversed in the larger breasted participants (above size 34D).

INTERPRETATION

To reduce tension on surgical incisions it is suggested that preference should be given to medial latitudinal locations for smaller breasted women and lateral latitudinal locations for larger breasted women.