Sports Bra Design and Bra Fit: Minimising Exercise- Induced Breast Discomfort Deirdre E
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University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections 2009 Sports bra design and bra fit: Minimising exercise- induced breast discomfort Deirdre E. McGhee University of Wollongong Recommended Citation McGhee, Deirdre E., Sports bra design and bra fit: Minimising exercise-induced breast discomfort, Doctor of Philosophy thesis, School of Health Sciences, University of Wollongong, 2009. http://ro.uow.edu.au/theses/3854 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] Sports bra design and bra fit: Minimising exercise-induced breast discomfort A thesis submitted in fulfilment of the requirements for the award of the degree Doctor of Philosophy from University of Wollongong by Deirdre. E. McGhee B. App. Sc. (Phty) School of Health Sciences 2009 Dedication I would like to dedicate this thesis to the most important people in my life, my darling husband, Philip, and my beautiful sons, Riley and Koen. II Certification I, Deirdre E McGhee, declare that this thesis “Sports bra design and bra fit: Minimising exercise-induced breast discomfort”, submitted in fulfilment of the requirements for the award of Doctor of Philosophy, in the School of Health Sciences, University of Wollongong, is wholly my own work unless otherwise referenced or acknowledged in this thesis. This thesis has not been submitted for a degree at any other university or institution. Deirdre E McGhee December 23, 2009 III Publications This thesis includes chapters that have been written as journal articles and includes: Chapter 2: McGhee, DE and Steele, JR. How do respiratory state and measurement affect bra size calculations? British Journal of Sports Medicine. 2006,40: 970-974. Chapter 3: McGhee, DE and Steele, JR. Optimising breast support in female patients through correct bra fit. A cross-sectional study. Journal of Science and Medicine in Sport. In press April, 2010. Chapter 4: McGhee, DE and Steele, JR. Relationship between breast volume, bra size and bra size cup size measurements in healthy women. Journal of Applied Ergonomics. Submitted for publication October, 2009. Chapter 5: McGhee, DE, Steele, JR. and Munro, BJ. Education improves bra knowledge and fit, and level of breast support in adolescent female athletes: A cluster-randomised trial. Journal of Physiotherapy. 2010, 56(1): 19-24. Chapter 6: McGhee, DE, Power, BM and Steele, JR. Does deep water running reduce exercise-induced breast discomfort? British Journal of Sports Medicine, 2007;41:879-883. Chapter 7: McGhee, DE, Steele, JR and Zealey, WJ. Breast kinetics and breast support during physical activity for females with large breasts. American Journal of Sports Medicine. Submitted for publication December, 2009 Chapter 8: McGhee, DE and Steele, JR. Breast elevation and compression decreases exercise-induced breast discomfort. Medicine and Science in Sports and Exercise. In press, May, 2010. As the primary supervisor, I, Professor Julie Steele, declare that the greater part of the work in each article listed above is attributed to the candidate, Deirdre McGhee. In each of the above manuscripts, Deirdre contributed to the study design, was solely responsible for data collection and data analysis, and was largely responsible for data interpretation. The first draft of each manuscript was written by the candidate and Deirdre was then responsible for responding to the editing suggestions of her co-authors. The co-authors, Julie Steele (Chapters 2-8) and Bridget Munro (Chapter 5), were responsible for assisting in study design, data interpretation and editing the manuscripts. Professor William Zealey provided intellectual input into the equations to determine breast forces, as well as manuscript editing (Chapter 7), whereas Bruce Power provided assistance with study design, data collection and analysis, and editing the manuscript (Chapter 6). Deirdre has been solely responsible for submitting each manuscript for publication to the relevant journals, and she has been primarily in charge of responding to reviewer’s comments, with assistance from her co-authors. Deirdre also took a lead role in developing the booklet Sports IV Bra Fitness, as described in the methods of Chapter 5, with the co-authors Julie Steele and Bridget Munro, contributing to editing and refining the booklet content and contributing intellectual input into the booklet design and publication. Deirdre E McGhee Professor Julie R Steele Candidate Primary Supervisor December, 2009 December, 2009 V Acknowledgments In completing this thesis, I wish to thank my supervisor Professor Julie Steele for her foresight, support and enthusiasm. Thank you also to my co-authors of the journal articles that form the body of this thesis, Bruce Power, Dr. Bridget Munro and Associate Professor William Zealey. I would also like to thank Steve Cooper for his ingenuity in designing the breast volume measurement device and to the members of the Biomechanics Research Laboratory who assisted with testing; Bruce Power, Sheridan Gho, Catherine Wild, Karen Mickle, Diane Harland and Simone Chambers. Special thanks to Suzi Edwards for her invaluable assistance with Visual 3D and to Karen Mickle for her eagle eye in the final editing. I am very grateful to all of the female subjects who volunteered their time and bodies for testing, despite the sensitivity of the experience. In particular, thanks to the Illawarra, South West Sydney, North Coast and Northern Inland Academies of Sport for the support and involvement of their female hockey and netball players. Special thanks to the IMB Community Foundation, the NSW Sporting Injury Committee and the Faculty of Health and Behavioural Sciences Research Committee for their foresight, belief in the project and financial support. I would like to apologise to my children for all the times over the past six years I neglected them for the sake of my thesis. Mum promises to spend less time on the computer from now on. To my mother, thank you for your undying support and guidance throughout my life, even when you could not understand the logic behind my actions. To my husband Phil, thank you for your love, understanding, patience, perspective and place of refuge; I could not have done this without you. Finally, thank you God for getting me through it and for it finally ending!! VI Abstract Background: Exercise-induced breast discomfort is a barrier to females participating in physical activity and has been associated with excessive vertical breast displacement. Sports bras have been designed to provide external breast support in order to minimise vertical breast displacement and, in turn, reduce exercise-induced breast discomfort. Adequate breast support during physical activity, however, requires both a supportive bra design as well as correct bra fit. Research Question: The overall aim of this thesis was to systematically investigate factors affecting the fit and design of bras worn during physical activity in order to develop breast support strategies to minimise the exercise- induced breast discomfort experienced by females when participating in physical activity. These strategies aimed to optimise bra fit and improve sports bra design through a greater understanding of breast biomechanics during physical activity. Methods: A series of studies was conducted in two sections, bra fit (Section A) and bra design (Section B). The laboratory-based bra fit studies (Chapters 2-4) investigated the various methods used to determine bra size as well as the bra wearing behaviour and bra fit ability of females. A field-based clinical trial was then conducted to assess the effect of an educational intervention related to bra fit and design on the knowledge and bra wearing behaviour of females (Chapter5). The bra design studies (Chapters 6-8) used biomechanical methods to measure breast kinematics and kinetics during different forms of physical activity (treadmill running and deep water running) and in different types of breast support (fashion bra versus sport bra versus novel sports bra design). Major Conclusions: Exercise-induced breast discomfort can be minimised by improving breast support through improvements in both bra fit and sports bra design. It is concluded that a revision of bra sizing guidelines and educating females in relation to professional bra fitting criteria are the main bra fit strategies to improve breast support and comfort during physical activity. For bra design, greater consideration of breast volume and breast shape, as well as the forces generated on the bra/breast spring, is recommended to offer improvements in breast support and comfort during physical activity. Specific bra cup design modifications, which can provide greater breast elevation and compression in encapsulation sports bras and increase the level of support relative to breast volume, are also suggested to improve breast support, in order to allow all females to exercise in comfort, irrespective of their breast size. VII Table of Contents Page Dedication ........................................................................................ II Certification ..................................................................................... III Publications ..................................................................................... IV Acknowledgements ......................................................................... VI Abstract ..........................................................................................