3-D breast anthropometry of plus-sized women in South Africa

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.

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.

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.

A Systematic Analysis of 3D Deformation of Aging Breasts Based on Artificial Neural Networks

The measurement and prediction of breast skin deformation are key research directions in health-related research areas, such as cosmetic and reconstructive surgery and sports biomechanics. However, few studies have provided a systematic analysis on the deformations of aging breasts. Thus, this study has developed a model order reduction approach to predict the real-time strain of the breast skin of seniors during movement. Twenty-two women who are on average 62 years old participated in motion capture experiments, in which eight body variables were first extracted by using the gray relational method. Then, backpropagation artificial neural networks were built to predict the strain of the breast skin. After optimization, the R-value for the neural network model reached 0.99, which is within acceptable accuracy. The computer-aided system of this study is validated as a robust simulation approach for conducting biomechanical analyses and predicting breast deformation.

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.

Head and facial dimensions of Chilean workers for design purposes and the differences with other populations

BACKGROUND: An appropriate match between a product and its end-users requires anthropometric data, which show variations among different countries. Proper Personal Protection Equipment (PPE) fit is key for safety and comfort. Chile had no head and facial anthropometric data available in order to design face/head PPE. OBJECTIVE: To describe face/head anthropometric characteristics of Chilean workers. Additionally, this study compared those dimensions against other populations (United States (US), South Korea and China). METHODS: An anthropometric survey involving 21 measures was conducted between September 2013 to May 2016 using stratified sampling. The measurements were based on ISO/TS 16976-2 and ISO 15535 to ensure the highest standards possible, and a total of 474 workers, aged from 18 to 66 years old, participated in the survey. RESULTS: The biggest differences were in Neck circumference, Weight, Nose breadth, Nose protrusion, Bitragion chin arc, Face length, Subnasale-sellion length, Face width, Bigonial breadth and Bitragion subnasal arc. Head length of Chileans were longer than Chinese and South Korean ones, but shorter than US Head length. Chilean Head breadth is smaller than Chinese and South Korean ones. Chileans Face length was the largest observed. Face width of Chileans was smaller than US and Chinese ones. Gender specific differences were also observed in the inter-country comparisons. Chilean males had larger anthropometric dimensions than females. CONCLUSION: Chilean Head and face dimensions differed significantly when compared against US, South Korean and Chines Head and Face dimensions. Chileans have longer and narrower faces with wider mouths, with a head size in between the US and Asian heads. Face and head PPE for Chileans should use dimensions in the current paper in order to ensure proper fit.

Assessing the female figure identification technique's reliability as a body shape classification system

This paper demonstrates the effects of slight differences in measurement definitions on resultant body shape classification. Ergonomic researchers consider the Female Figure Identification Technique (FFIT) a 'gold standard' body shape classification system to describe variation in a population's 3 D profile. Nevertheless, researchers use FFIT without a scientific basis or considering their ergonomic suitability. This paper rigorously evaluates FFIT, focussing on ergonomics, garment construction, and scientific research applications. Through analysing 1,679 3 D Body Scans, we assess the level of agreement between the FFIT's body shape classification when measurements placed following FFIT's or SizeUK's guidance. We establish how different interpretations of FFIT's measurement placement cause the same body to be categorised into different shapes - in up to 40% of cases. FFIT omits shoulder measurements that have little relationship to body shape yet are vital in garment construction. Using FFIT with different datasets and definitions, therefore, leads to inconsistent conclusions about shape differences.

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.

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.

Anthropometric characteristics of Chilean workers for ergonomic and design purposes

Obtaining an appropriate match between a product and its end-users requires anthropometric data, which are typically outdated and show variations among different countries. Chile had its anthropometric data taken nearly 20 years ago, thus they are probably outdated. The purpose of this article is to describe some anthropometric characteristics of Chilean workers. An anthropometric survey involving 27 measures and five calculated body dimensions was conducted in 2016. The measurements were based on ISO 7250 and ISO 15535 to ensure the highest standards possible, and a total of 2946 workers, aged from 18 to 76 years old, participated in the survey. The results showed that Chilean workers have smaller dimensions than Dutch and US workers but have larger dimensions than South Koreans. The data presented in this article constitute the most up-to-date anthropometric dataset describing the dimensions of Chilean workers. Practitioner Summary: In Chile, women are smaller and weigh less than men, and both of these populations have high body mass index (BMIs). In addition, the Chilean population exhibits substantial differences compared with other international adult populations. The data presented in this article should be used as a reference when designing for Chilean workers.

A review of the methodology and applications of anthropometry in ergonomics and product design

Anthropometry is a key element of ergonomic studies for addressing the problem of fitting the tasks/products to user characteristics, but there is a gap between anthropometric data and their application for designing ergonomic products and environments. This research was conducted to review the literature on the methodology and applications of anthropometry for the ergonomic design of products and environments, and to identify where further research is needed to improve its application and evaluation protocols. One hundred and sixteen papers meeting the inclusion criteria were reviewed. Although a number of anthropometric investigations have been conducted to improve the design of products/environments for different users, further research seems to be necessary, particularly for special groups, such as children, the elderly and people with disabilities. Different anthropometric measurement methods/techniques and fitting criteria are discussed regarding their applicability for various design applications. This review also highlights methodological issues (sampling considerations and prototype evaluation and testing) that should be considered in future research to ensure a user-centred approach of the design process. Practitioner Summary: A literature review was conducted on the methodology and applications of anthropometry for the ergonomic design of products/environments. This review emphasises the need for anthropometric research to design for special groups, such as children, the elderly and people with disabilities, and methodological issues that should be considered in future research. Abbreviations: 1D: one-dimensional; 2D: two-dimensional; 3D: three-dimensional; HF/E: Human Factors/Ergonomics; PCA: Principal Components Analysis; CA: Cluster Analysis; DHM: Digital Human Modelling.

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.

Breast volume is affected by body mass index but not age

BACKGROUND

This study aimed to establish normative breast volume data for women of varying ages, body masses and breast sizes, and to determine the effect of age and body mass index (BMI) on breast volume.

METHODS

The breast volume of 356 women (age range: 18.1-83.7 years; BMI range: 18.4-54.5 kg/m²) was measured using three-dimensional scanning in a prone position.

RESULTS

Breast volumes ranged from 48 to 3100 mL. Although breast volume was not significantly affected by age, it was significantly affected by BMI, with the breast volume of overweight and obese women being two-to-three times greater than women with normal BMI's.

CONCLUSION

It is recommended that bra cups must be designed to support the wide range and increasing magnitude of breast volumes exhibited by women. Practitioner summary: This original research provides evidence for bra designers and manufacturers on the range of breast volumes of women and the significant effect of BMI on breast volume. Bra cups need to be designed to support the wide range and increasing magnitude of breast volumes exhibited by women.

Scan posture definition and hip girth measurement: the impact on clothing design and body scanning

Ergonomic measurement is central to product design and development; especially for body worn products and clothing. However, there is a large variation in measurement definitions, complicated by new body scanning technology that captures measurements in a posture different to traditional manual methods. Investigations of hip measurement definitions in current clothing measurement practices supports analysis of the effect of scan posture and hip measurement definition on the circumferences of the hip. Here, the hip girth is a key clothing measurement that is not defined in current body scanning measurement standards. Sixty-four participants were scanned in the standard scan posture of a [TC]² body scanner, and also in a natural posture similar to that of traditional manual measurement collection. Results indicate that scan posture affects hip girth circumferences, and that some current clothing measurement practices may not define the largest lower body circumference. Recommendations are made concerning how the hip is defined in measurement practice and within body scanning for clothing product development. Practitioner Summary: The hip girth is an important measurement in garment design, yet its measurement protocol is not currently defined. We demonstrate that body posture during body scanning affects hip circumferences, and that current clothing measurement practices may not define the largest lower body circumference. This paper also provides future measurement practice recommendations.

A novel fully automatic measurement of apparent breast volume from trunk surface mesh

This paper presents a novel method for assessing apparent breast volume from trunk surface mesh without any manual intervention. The proposed method requires a closed and smooth triangular mesh of the trunk. It comprises four main steps: automatic nipple localization, automatic breasts delineation, chest-wall interpolation and volume computation. The mean curvature is computed for each vertex using a quadratic fitting approach and used as an indicator to determine the convex fold of the breasts. The delineation is modeled as an ellipse in the frontal plane and all the vertices inside it are removed. The remaining ones are used to interpolate the chest wall with radial basis functions. The voxels inside the resulting mesh without breasts are then subtracted from the original voxelized volume to generate the breasts volume. The validation is conducted on 30 adolescent female for each of which an MRI and a trunk surface (TS) acquisitions were available. Three breast volumes are considered: the anatomical volumes (AV) manually segmented on the MRI, the external volumes computed with the proposed method first in prone position (EVP) using the trunk mesh extracted from the MRI, and second, in standing position (EVS) using the TS's mesh. Significant correlations (R> 0.77) are found between each two of the three volumes. AVs are much larger than both EVS and EPS. In fact, the manual segmentation using MRI slices allows for a direct visualization of the breast posterior delineation. Computed automatically, EVS and EPS are highly similar, indicating that the proposed method is robust to changes from prone to standing position. No significant difference between the regressions on the left and right breasts is noted. Fully-automatic 3D breast volumetry from trunk surface mesh is feasible and provides measurements that are highly correlated to manual MRI volumetry and robust to changes in posture.

Using subject-specific three-dimensional (3D) anthropometry data in digital human modelling: case study in hand motion simulation

Digital human modelling enables ergonomists and designers to consider ergonomic concerns and design alternatives in a timely and cost-efficient manner in the early stages of design. However, the reliability of the simulation could be limited due to the percentile-based approach used in constructing the digital human model. To enhance the accuracy of the size and shape of the models, we proposed a framework to generate digital human models using three-dimensional (3D) anthropometric data. The 3D scan data from specific subjects' hands were segmented based on the estimated centres of rotation. The segments were then driven in forward kinematics to perform several functional postures. The constructed hand models were then verified, thereby validating the feasibility of the framework. The proposed framework helps generate accurate subject-specific digital human models, which can be utilised to guide product design and workspace arrangement. Practitioner Summary: Subject-specific digital human models can be constructed under the proposed framework based on three-dimensional (3D) anthropometry. This approach enables more reliable digital human simulation to guide product design and workspace arrangement.

Volumetric differences in body shape among adults with differing body mass index values: An analysis using three-dimensional body scans

OBJECTIVES

This study quantified differences in body shape of people differing in body mass index (BMI), using three-dimensional (3D) scan-extracted segmental body volumes.

METHODS

Eight segmental volumes were measured on 340 young adults (169 males and 171 females) aged 18-30 years, using the Vitus Smart 3D whole body scanner. Body volumes were also expressed as a ratio of the sex-specific mean volume (segmental or whole body) and compared to BMI using simple linear regression, multiple-segment-linear regression and Lowess curves.

RESULTS

While all segmental volumes increased significantly as BMI increased, the BMI-related patterns of increase varied among different body segments. For example, pelvis and abdomen volumes increased at a significantly greater rate than whole body volume, with the rates of increase greatest in the overweight and obese.

CONCLUSIONS

Body shape changes due to variations in body volume could have important implications in a range of fields that currently use 1D anthropometric measurements that do not capture body shape differences in the same detail.

Bra-breast forces generated in women with large breasts while standing and during treadmill running: Implications for sports bra design

This study aimed to determine the bra-breast forces generated in women with large breasts while these women wore different levels of breast support during both upright standing and treadmill running. The mean bilateral vertical component of the bra-breast force in standing was 11.7 ± 4.6 N, whereas during treadmill running the mean unilateral bra-breast force was 8.7 ± 6.4 N and 14.7 ± 10.3 N in the high and low support conditions, respectively. Furthermore, breast mass was significantly correlated with vertical breast displacement (R(2) = 0.62) in the high support condition. The wide range of breast masses of women with large breasts is an important consideration for designers of sports bras to ensure these bras can reduce force generation and breast discomfort by providing a high level of breast support while these women participate in physical activity.

Evaluation of professional bra fitting criteria for bra selection and fitting in the UK

A correctly fitting bra is essential for good health; this study investigates the use of professional bra fitting criteria to establish best-fit in an underwire bra commonly sold in the UK. A comparison was made between women's bra size as measured by the traditional bra fitting method with their recommended bra size based on professional bra fitting criteria. Forty-five female participants were recruited; their mode self-reported bra size was 34DD. Participants were measured in their own bra using the traditional bra-fitting method to establish their 'traditional size'. A 'best-fit' bra size was recorded for participants based on professional bra fitting criteria. Significant differences were found between traditional and best-fit cup and band sizes (p < 0.001); the traditional method of bra fitting overestimated band size and underestimated cup size. As band size increased the traditional method also became more inaccurate (p < 0.001). It is recommended that women are educated in assessing their own bra fit using professional bra fitting criteria and less emphasis placed on determining absolute bra size. Practitioner Summary: This is the first study to investigate using professional bra fitting criteria to establish best-fit in an underwired bra commonly sold in the UK. The traditional method of bra fitting was found to be inadequate, especially for larger-breasted women; the use of professional bra fitting criteria should be encouraged.