Changes to breast structure and function across a woman's lifespan: Implications for managing and modeling female breast injuries.

BACKGROUND: Female breasts change throughout a woman's life in response to fluctuating hormonal influences. Individuals managing active women and those modeling female breasts must understand these structural and functional changes across a female's lifespan because these changes affect breast injuries sustained by women. METHODS: We initially review female breast structure and function and then describe how breast structure changes across a woman's lifespan. Key studies about direct contact and frictional breast injuries are then summarized. Limitations of current breast injury research, gaps in knowledge about breast injuries incurred by specific populations, and the lack of breast injury models are also highlighted. FINDINGS: With minimal anatomical protection, it is unsurprising that breast injuries occur. Although research about breast injuries is scant, direct contact during blunt force trauma to the anterior chest wall and frictional breast injuries have been reported. There is a lack, however, of research documenting the incidence and severity of breast injuries incurred in occupational settings and in women's sports. Therefore, to design effective breast protective equipment, we recommend research to model and investigate the mechanisms and forces involved in breast injuries, particularly injuries sustained during sport. INTERPRETATION: This unique review summarizes how female breasts change over a woman's life span, with implications for breast injuries sustained by females. Knowledge gaps about female breast injuries are highlighted. We conclude by recommending research required to develop evidence-based strategies to improve how we classify, prevent, and clinically manage breast injuries sustained by females. SUMMARY: We review changes to the breast across a woman's lifespan, highlighting implications for managing and modeling female breast injuries.

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.

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.

Physical side-effects following breast reconstructive surgery impact physical activity and function.

PURPOSE: To investigate the incidence and severity of physical side-effects experienced by women following breast reconstructive surgery and the effect of these side-effects on physical activity and function. METHODS: Two hundred and thirty-one Australian women (55 years SD 6.5) who had previously had breast reconstruction surgery retrospectively self-reported the incidence and severity of eight physical side-effects and the perceived effect of these side effects on six physical functions, at three time points after their surgery. The frequency of the combined incidence/severity scores and their impact at the three time points were tabulated and compared using Chi-squared tests. A general linear regression was used to identify characteristics associated with moderate-very high (≥ 5/10) combined incidence/severity scores. RESULTS: At 6 months following surgery, approximately 50% of respondents reported moderate to very high incidence/severity scores for physical side-effects across multiple body regions, which were perceived to limit their physical function and activity levels. The highest incidence/severity scores were associated with the following: (i) pre-existing physical problems before surgery, (ii) post-operative complications (seroma, infection, necrosis), and (iii) autologous rather than implant-based reconstructions. CONCLUSION: A large percentage of women reported moderate to severe physical side-effects across multiple body regions following breast reconstructive surgery. These side-effects were perceived to negatively impact both physical function and activity. Early intervention, education and treatment are recommended to alleviate these issues and minimise their negative impact.

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.

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.

The Attachments of the Breast to the Chest Wall: A Dissection Study.

BACKGROUND: The anatomical descriptions of the attachments of the female breast to the chest wall vary in their structure, location, and terminology within the published literature. METHODS: A dissection study of the attachments of the breast to the chest wall was conducted on 18 female embalmed breasts in the coronal (n = 15) and sagittal planes (n = 3). RESULTS: Perimeter, posterior wall, and horizontal septum attachments were observed. The perimeter along its entire length was attached to the chest wall. Regional and anatomical variation was observed in this structure and location. Sharp dissection was required to remove it from the chest wall, in contrast to the blunt dissection required to remove the posterior wall and horizontal septum attachments. CONCLUSIONS: The breast attaches to the chest wall along its entire perimeter, posterior wall, and horizontal septum, with the perimeter functioning as the primary anchor of the breast to the chest wall. The structure of the perimeter attachment is both periosteal and fascial and requires sharp dissection to remove it from the chest wall. The fascial structures of the posterior wall and horizontal septum require blunt dissection only. The structure of the perimeter has regional variation, and its location on the chest wall has anatomical variation. Detailed anatomical descriptions and illustrations are supported by photographic evidence of cadaver dissections in two planes. Clinical and anatomical terminology are linked, with clinical implications for medical anatomy education, breast modeling, and breast surgery.

Breast and torso characteristics of female contact football players: implications for the design of sports bras and breast protection.

This study aimed to provide normative data characterising the breast size, breast position and torso size of female contact football players. 117 AFL, Rugby League, Rugby Union and Rugby 7s players attended a single testing session where a three-dimensional scan was taken of their naked breasts and torso. Dimensions relevant to the design of sports bras and breast protective equipment were then calculated from the scans. Several breast and torso characteristics of female contact football athletes differed to measurements reported for females in the general population and amongst the contact football codes. Designers and manufacturers of sports bras or breast protective equipment should consider the specific breast and torso dimensions of female contact football players to maximise the fit, comfort and efficacy of these garments. Practitioner summary: Using three-dimensional scanning, this study characterised the breast and torso size and shape of 117 female contact football players. These normative data should be used to improve the fit and comfort of sports bras and breast protective equipment for female contact football players.

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.

Effects of obesity on breast size, thoracic spine structure and function, upper torso musculoskeletal pain and physical activity in women.

Purpose: This study investigated the effects of obesity on breast size, thoracic spine structure and function, upper torso musculoskeletal pain and physical activity participation in women living independently in the community. Methods: A total of 378 women were divided into 3 groups (Not Overweight: body mass index (BMI) = 22.5 ± 0.2 kg/m2 (mean ± SE); Overweight: BMI = 27.4 ± 0.3 kg/m2; Obese: BMI = 35.4 ± 0.3 kg/m2). Outcome variables of breast volume (mL), thoracic flexion torque (N·m), thoracic kyphosis (degrees), upper torso musculoskeletal pain (score) and time spent in physical activity (min) were calculated and compared among the 3 groups, adjusting for between-group differences in age. Results: There was a significant main effect of BMI on all outcome variables. Participants classified as Obese displayed significantly larger breasts, had greater thoracic flexion torques and reported less time participating in physical activity relative to the participants who were classified as Not Overweight and Overweight. Participants in the Obese group also displayed significantly more thoracic kyphosis and reported significantly more upper torso musculoskeletal pain compared to their counterparts who were classified as Not Overweight. Conclusion: This study is the first to demonstrate that increased obesity levels were associated with compromised kyphosis and loading of the thoracic spine, as well as increased symptoms of upper torso musculoskeletal pain and reduced time spent in physical activity in women living in the community. We recommend further research to determine whether evidence-based interventions designed to reduce the flexion torque generated on the thoracic spine can improve these symptoms of upper torso musculoskeletal pain and the ability of women with obesity to participate in physical activity.

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.

Breast pain affects the performance of elite female athletes.

Although breast pain is problematic for many active women, no published research has investigated breast pain experienced by elite female athletes. This study aimed to examine the extent that mastalgia and exercise-induced breast pain affected the sporting performance of elite female athletes during training and competition. A custom-designed online survey with questions related to sport participation, as well as the frequency, severity and perceived performance effects of mastalgia and exercise-induced breast pain, was distributed to sporting organisations, coaches, medical staff and teams/clubs throughout Australia. Five hundred and forty female athletes competing nationally or internationally across 49 different sports participated in the survey. Sixty-three percent of respondents reported experiencing breast pain associated with their menstrual cycle and 33% reported that this pain worsened during activity. Forty-four percent of athletes reported experiencing exercise-induced breast pain during training or competition. Both types of breast pain were also reported to negatively affect sporting performance (20% and 32%, respectively). Mastalgia associated with the menstrual cycle and exercise-induced breast pain should be acknowledged as potential problems affecting the sporting performance of elite female athletes. Awareness around the impact of breast pain and the development and implementation of breast pain management strategies are essential for this population.

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 fibro-adipose structure of the female breast: A dissection study.

A paucity of dissection evidence and quantitative data exists to base anatomical descriptions and illustrations of the fibro-adipose structure of the female breast. The aim of this study was to dissect and provide quantitative data of the fibro-adipose structure of the female breast. The fibro-adipose structure of female embalmed breasts were dissected in the coronal (n = 15) and sagittal planes (n = 3). Quantitative data of breast volume, surface area, fibro-adipose pocket number, size and regional variation were collected. Pearson's correlations were used to investigate pocket number and size with breast volume and surface area. Regional variation in pocket number and size were compared using T tests. Throughout the dissection, photographic evidence was collected to support detailed anatomical descriptions. The mean (SD; range) number of pockets located in the superficial region of the breast was 199 ± 53 (108-306) and the mean pocket surface area was 0.88 ± 0.37 cm2 (0.31-1.97). A strong correlation was found between mean pocket number and breast surface area (r2 = 0.8064) and a very weak correlation between mean individual pocket surface area and breast surface area (r2 = -0.1427; P < 0.01). The pockets located anterior to the corpus mamma were significantly larger and less in number (P < 0.05) than those located posterior. The fibro-adipose structure of the female breast is formed by complex scaffolding, consisting of layers of fibrous tissue pockets embedded with adipose tissue which surrounds the corpus mamma and is firmly attached to the perimeter of the breast. Detailed descriptions are supported by quantitative data and photographic evidence. Clin. Anat. 32:146-155, 2019. © 2019 Wiley Periodicals, Inc.

The Occurrence, Causes and Perceived Performance Effects of Breast Injuries in Elite Female Athletes.

Female breasts are vulnerable to direct blows or frictional injuries during sport; however, little research has investigated breast injuries experienced by female athletes. This study aimed to investigate the occurrence, causes and perceived performance effects of breast injuries in elite female athletes across a wide range of sports. A custom-designed survey was distributed to female athletes aged over 18 years who were competing nationally or internationally in their chosen sport. The survey included questions about breast injuries sustained during training and competition and any perceived performance effects of these injuries. 504 elite female athletes from 46 different sports completed the survey. 36% of participants (n = 182) reported experiencing breast injuries and 21% (n = 37) perceived that their breast injury negatively affected their performance. Contact breast injuries were reported by significantly more athletes involved in contact or combat sports and by athletes with larger breasts or a higher body mass index. Frictional breast injuries were reported by significantly more older athletes or those with larger breasts. Less than 10% of participants who experienced breast injuries reported their injury to a coach or medical professional and only half used any prevention strategies. Athletes, coaches and medical professionals associated with women's sport need to be made aware of the occurrence and potential negative effects of breast injuries. It is critical to normalise conversations around breast health so that athletes can be encouraged to report and, when necessary, receive treatment for breast injuries. Further research is also required to better understand factors that affect breast injuries in sport in order to develop evidence-based breast injury prevention strategies.

Effect of Breast Size on Upper Torso Musculoskeletal Structure and Function: A Cross-Sectional Study.

BACKGROUND: Research has shown that women with large and hypertrophic breast sizes report an increased prevalence and severity of musculoskeletal pain in the upper torso. Despite this evidence, factors contributing to the development of musculoskeletal pain among these women are poorly understood, and the threshold at which breast size becomes problematic in terms of musculoskeletal pain is currently unknown. METHODS: Three hundred Australian women (aged 18 to 82 years) who volunteered as participants were divided into four breast size groups (small, breast volume <350 ml; medium, breast volume 350 to 700 ml; large, breast volume 701 to 1200 ml; and hypertrophic, breast volume >1200 ml). The thoracic flexion torque, thoracic kyphosis angle, total upper torso musculoskeletal pain score, and regional upper torso musculoskeletal pain scores derived for participants in the four groups were compared using an analysis of covariance design, controlling for age and body mass index. RESULTS: Thoracic flexion torque significantly increased as breast size group increased. Women with hypertrophic breasts reported significantly higher total upper torso musculoskeletal pain scores compared with women who had small, medium, and large breasts, and this was significant for the upper back, shoulders, neck, and breasts. No significant difference was found in thoracic kyphosis angle among the four groups. CONCLUSIONS: Musculoskeletal pain became most pronounced in women with hypertrophic breasts who had the greatest breast volume and displayed the greatest thoracic flexion torque. Clinical and/or surgical treatment for symptomatic relief should aim to either counteract thoracic flexion torque or reduce breast volume. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, I.

Does breast size affect how women participate in physical activity?

OBJECTIVES: Research has shown that women with large breasts experience increased breast motion, which can act as a barrier to participating in physical activity. Despite this evidence, limited research has investigated the effect of breast size on physical activity participation. DESIGN: Cross-sectional study. METHODS: 355 Australian women (aged 18-75years) who volunteered as participants were divided into four breast size groups (small, medium, large and hypertrophic). All participants completed the Active Australia Survey to assess their participation in physical activity in the previous week, and were asked to indicate whether they agreed or disagreed that their breast size affected their participation in physical activity. Participant responses to time spent in each type of activity were compared across the four breast size groups using an ANCOVA design, controlling for age. RESULTS: Participants with hypertrophic breasts participated in significantly less total physical activity per week, particularly less vigorous-intensity physical activity, compared to their counterparts with smaller breasts. Participants with large breasts also participated in less vigorous-intensity physical activity compared to participants with small and with medium breasts, and a high percentage of women with large and with hypertrophic breasts perceived their breast size to affect the amount and intensity of physical activity they performed. CONCLUSIONS: Breast size should be acknowledged as a potential barrier to women participating in physical activity. Strategies to assist women with large and hypertrophic breasts participate in all types and intensities of physical activity are needed so women can enjoy the health benefits associated with an active lifestyle.

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.

Can breast characteristics predict upper torso musculoskeletal pain?

BACKGROUND: Several studies have associated a large breast size with an increased prevalence and severity of musculoskeletal pain, particularly pain in the upper torso. Despite this evidence, no research has explored whether breast size or related characteristics are risk factors for upper torso musculoskeletal pain. METHODS: A backward multiple regression analysis was performed to identify whether characteristics of the breasts and upper torso, as well as physical factors known to be associated with musculoskeletal pain, could predict musculoskeletal pain among a cohort of 378 Australian women aged 18 years and over who had a wide range of breast sizes. FINDINGS: The model identified that breast volume, age and nipple-to-nipple distance predicted 23% of the variance in upper torso musculoskeletal pain reported by the participants. INTERPRETATION: Women with a larger breast volume, lower age and a greater nipple-to-nipple distance were predicted to report a higher upper torso musculoskeletal pain score.

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.