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Breast pain is a prevalent condition in the UK (52%) which can negatively impact women's quality of life. Research identified that bras can effectively reduce breast pain in women with larger breasts, yet, no randomised controlled trial has been conducted, despite bras being recommended as a treatment. Previous research reports that one bra design may not be suitable for all women with larger breasts indicating that bras should be specific to the individual. Within a clinical environment, based on Medical Research Council guidelines, the overall aim of this thesis was to develop, pilot and evaluate a bra intervention for women with larger breasts who are experiencing breast pain. As with other populations of women, the appropriateness of a bra for this cohort is likely to be multifactorial, influenced by both subjective and objective variables. Therefore, the first study, used a focus group and interviews to determine the performance variables for assessing bra appropriateness. Due to the substantial choice available within the UK lingerie market, these bra performance variables were used to develop a novel bra selection criteria which was applied to the UK lingerie market in study two and resulted in the selection of six everyday bras for assessment within the bra intervention study. Chapter Four, then identified four key bra performance variables from study one (comfort, support, fit and aesthetics) and used these to develop methods (subjective and objective) to individually prescribe one of the bras. In Chapter Five, a review of literature and pilot investigations identified the methods for assessing the effectiveness of the bra intervention including determining three important outcome measures; the Patient's Global Impression of Change Scale, a Numerical Rating Scale (breast pain intensity) and the SF-36 (quality of life). Having developed all aspects of the bra intervention, study three then piloted this intervention using the Queen Alexandra Hospital Portsmouth as a recruitment site. Patients were randomly assigned to either the standard care group or the intervention group where patients had a bra individually prescribed, and then wore this bra for eight weeks. Outcome measures were assessed at four and eight weeks. Recruitment (n = 34) and retention of patients was poor (33% drop out in the bra prescription group and 50% drop out in the standard care group), however, a significant improvement in quality of life (χ2 = 8.667, P = 0.010) was identified within the bra prescription group. Evaluation of this bra intervention suggested that there were barriers to patient participation. Study four investigated these barriers for this population. Less than half of patients surveyed (43%) were interested in the bra prescription, perhaps because 84% felt they were wearing a well-fitting bra, despite study three identifying that 91% of patients within the bra prescription group were not wearing a well-fitting bra. Aside from this, time constraints were the largest barrier to participation. Study five was a comparative survey-based study with non-clinic cohorts. The pregnant and breastfeeding group (82%) and younger adults group (72%) were the most likely to report they would take up the bra prescription service. Fewer women felt they were wearing wellfitting bras (range = 55% to 83%), possibly explaining the high level of interest. Time constraints continued to be a barrier to participating. The outcomes of this study suggests that those within the clinical population need further education to ensure they understand the benefits of appropriately fitting bras. In conclusion, this was the first study to develop, pilot and evaluate a bra intervention using a bra prescription for women with larger breasts and breast pain. This study established a framework for prescribing a bra, which could be applied to other populations. Although the efficacy of the intervention was inconclusive due to a low sample size, there was a positive impact on quality of life. The intervention should therefore be developed further. With the current population there should be a focus on educating patients on appropriate bra fit in order to encourage them to utilise such a service. The trial should then be re-run as an observation or patient-preference trial, to understand the effect of the bra prescription on breast pain, prior to re-running the randomised controlled trial. Alternatively, the bra intervention could be refocused on a non-clinic population, such as pregnant and breastfeeding women, who are more likely to take up the bra prescription.

The breast contains no muscle or bone and its primary supporting structures are reported to be the skin and Cooper’s ligaments. It has been hypothesised that independent breast motion, which is already known to cause pain for many women, may also cause damage to the breast structure leading to breast ptosis (sag). Breast damage could be estimated by applying the published strain failure limits (60%) for human skin to measurements of breast skin strain. However, there have been few attempts to measure breast skin strain as gravitational deformation makes it difficult to identify the neutral breast position in which there is no external strain on the breast skin. A gold-standard method for estimating the neutral breast position based on Archimedes’ principle was developed and implemented within this thesis. Fourteen female participants, with breast sizes 30 to 34 under band and B to E cup size, had semi-permanent henna markers applied to their torso (4 markers) and left breast (an array of 17 markers including the nipple). Participants were immersed up to their neck in two fluids with mass-densities above (water) and below (soybean oil) the reported range of breast mass-densities (919 kg.m-3 to 986 kg.m-3). The mid-point between the breast position in water and soybean oil provided the gold-standard neutral position estimate. Participants also performed nine alternative novel or previously published methods for estimating the neutral breast position. Alternative methods were assessed for accuracy and precision when estimating the gold-standard neutral nipple position. To investigate the effects of gravity and dynamic activity on the breast, participants had their breast displacement and breast skin strain assessed in the static gravity-loaded (bare-breasted) position and during an incremental-speed (bare-breasted) treadmill test (4 kph to 14 kph). Breast pain was recorded in each condition using an 11-point numerical rating scale. The gold-standard method was implemented to obtain an accurate (measurement error ≤ 1.4 mm) and precise (TEM ≤ 1.2 mm, SD ≤ 3.7 mm) measurement of the neutral breast position. Evaluation of novel and previously published neutral position methods revealed that the buoyancy in water method achieved the most accurate estimation of the gold-standard neutral nipple position (absolute differences ≤ 5.6 mm, TEM ≤ 1.2 mm, SD ≤ 2.6 mm). Comparison of the gravity-loaded and neutral breast positions demonstrated that gravity caused the nipple to move posteriorly (mean change 15.6 mm), laterally (mean change 7.5 mm) and inferiorly (mean change 25.9 mm) relative to the torso, and induced potentially damaging skin strains up to 75%. During bare-breasted incremental-speed treadmill activity the nipple was displaced furthest from the neutral position in the inferior direction (mean of 45.5 mm); a result which could not be attained using conventional measurements of nipple range of motion (ROM). Strain analysis indicated potentially damaging skin strains during the incremental-speed treadmill activity (up to 114%), particularly in the upper-outer region of the breast. This finding supports the anticipated relationship between breast motion and breast damage. Breast pain was most strongly correlated to superior nipple displacement from the neutral position during treadmill activity (p < 0.001, r = 0.725), and a significant correlation was observed between breast pain and breast skin strain (p < 0.001, r = 0.361). Combination of breast displacement and skin strain data provided a comprehensive analysis of the effect of gravity- and motion-induced breast displacements on the breast skin. Incorporation of the neutral breast position into future biomechanical research may lead to improved assessment of breast motion and breast damage, and a deeper understanding of motion-induced breast pain. Within clinical research, identification of the neutral breast position may enable the development of breast models that are better able to predict the gravitational deformation of the breast during surgery. Consideration of the neutral breast position, and subsequent breast strain, also has applications within the field of breast support design and evaluation. A breast support garment that positions the breast in the neutral position and restricts motion to within the reversible strain limits of the skin may protect the breast from skin damage and the associated breast pain.

Developing a scientific understanding of the breast support implications for the female recreational athlete will make a significant contribution to the breast biomechanics literature, provide valuable information to bra designers and help athletes make informed decisions about their breast support requirements. The work in this thesis determined the effect of a high and low breast support condition on biomechanical and perceptual variables during steady-state running, intermittent exercise and vertical jumping in a population of larger-breasted female recreational athletes. In order to assess breast kinematics an appropriate method of assessing bra fit was needed. Within this programme of research the use of best-fit criteria was first developed and then demonstrated that traditional bra fit methods overestimate band size (76% of participants) and underestimate cup size (84% of participants). During all activity modes a well-fitted high support bra significantly (p < 0.05) reduced breast kinematics and increased breast comfort. For steady-state running, alterations in lower-extremity biomechanics led to more distance being covered per minute (3.08 m; p = 0.006) and therefore a potential for improved performance when participants ran with high breast support. More acute knee flexion during sprinting (p = 0.008) and less sagittal plane thorax range of motion (p < 0.044) in the high breast support condition during the intermittent treadmill protocol could also benefit running performance. Increases in the range of motion of upper-extremity variables during treadmill activity were related to increases in some breast kinematic variables (r = 0.465 to 0.742); therefore certain individuals may require greater breast support than others. With increased breast kinematics there was a trend towards participants landing from vertical jumps with lower ground reaction forces coupled with increased thorax, thigh and knee flexion (r = 0.564 to 0.607). This suggests participants attempted to soften their landing, which may affect subsequent performance. Vertical jumping and sprinting elicited the highest magnitudes of vertical (0.08 m) and mediolateral (0.03 m) breast displacement respectively, questioning whether steady-state running is the most effective activity mode for testing bra efficacy. The reduction of anterioposterior breast kinematics should also be a consideration for bra design as they related most closely to breast comfort and biomechanical variables across all activity modes. Knowledge of the breast support implications for larger-breasted female recreational athletes was progressed in this thesis and bras offering high multi-planar support are promoted as they were found to be beneficial for performance within the activities investigated.

Whilst sports bras have been reported to significantly reduce breast kinematics and exercise-related breast pain, little is known about the effect of breast support on running biomechanics. This research area has novel applications and many potential benefits to female athletes. Papers available within this area hypothesise that the reduction of breast kinematics and exercise-related breast pain, provided by a high breast support, ensures running biomechanics are maintained and potentially enhanced, however, few have provided evidence of this. To investigate this area this thesis explored biomechanical measures during running including; breast biomechanics, full body running kinematics, and an examination of upper body muscle activity during a five kilometre treadmill run, in low and high breast support conditions. An integrated programme of work was conducted with multiple variables collected and presented in chapter four to seven. Chapter three identified significant changes in breast kinematics during a prolonged treadmill run, and defined the run duration for this programme of work. Chapter four examined breast biomechanics during a five kilometre treadmill run, in different breast support conditions. In line with previous publications, the high breast support provided superior magnitudes of support to the breasts (up to 75% reduction) compared to the lower breast support conditions, and significant reductions in exercise-related breast pain throughout treadmill running. Increases in multiplanar breast displacement, velocity, acceleration, and approximated force were reported from the start to the end of the five kilometre run in both low (increases of 7 mm, 0.10 m.s-1, 5.6 m.s-2, 3 N) and high (5 mm, 0.07 m.s-1, 2.7 m.s-2, 1 N) breast supports. These novel findings demonstrate that breast kinematics increase during a five kilometre treadmill run, which may directly affect an individual’s running biomechanics. Assessing the magnitude of variance associated with breast biomechanics data ensures accurate interpretation of the reported findings. To achieve this, within- and between participant variance in multiplanar breast kinematics were quantified utilising the coefficient of variance (Cv%). The smallest differences in breast kinematics reported in the third chapter exceeded the reported within-participant variance in both low (12 Cv%) and high (15 Cv%) breast supports, and were therefore defined as meaningful differences. Between-participant variance in multiplanar breast kinematics in low (23 Cv%) and high (29 Cv%) breast supports was greater than the within-participant variance, and should be considered in future for research designs and sample sizes. To assess running kinematics between breast supports, a full body kinematic analysis was conducted including the quantification of step length and full body Cardan joint angles. When running in the lower breast support conditions, costly running mechanics such as greater thorax flexion, shorter step length, less acute knee angle, greater arm swing mechanics, and greater axial rotation of the thorax and pelvis were reported. However, the high breast support exhibited a kinematic profile more closely aligned with a desirable, economic running style previously defined within the literature. These findings support claims that the breast support worn may impact upon biomechanical parameters, with high breast support eliciting advantageous running kinematics. This unique work found female runners will alter their running kinematics depending upon the breast support worn. Changes in running kinematics away from an individual’s natural kinematics have been linked to changes in the activation of muscles driving these movements. Therefore, given the reported differences in upper body running kinematics, the effect of breast support on the activity of six upper body muscles central to running was examined and reported. Reductions in normalised peak activity of the pectoralis major (37% reduction), anterior deltoid (26 reduction) and medial deltoid (30% reduction) were reported in the high breast support; suggesting that a high breast support significantly reduces the peak activation of these three muscles compared to lower breast support conditions during running. Furthermore, the differences in activity of these muscles are thought to be associated with the changes in upper body kinematics, specifically arm swing mechanics. The research design of this programme of work enabled relationships between the key biomechanical measures to be explored, providing a holistic view of the effect of breast support on the biomechanics of the female runner. Relationships were identified between the magnitude of breast kinematics, which is governed by the breast support worn, and the following biomechanical measures investigated; exercise-related breast pain, upper and lower body running kinematics and upper body muscle activity. Furthermore, certain running kinematics demonstrated significant relationships to muscle activity. This research has shown that breast biomechanics, running kinematics and upper body activity are affected by the breast support worn during treadmill running. The use of high breast support has demonstrated the potential of this breast support to benefit running biomechanics. This novel programme of work has progressed the knowledge of the effect of breast support on both breast and body biomechanics during treadmill running.

Profound changes occur within the female breast with increasing age; glandular atrophy, increased skin laxity and stretched Cooper‟s ligaments cause an inferior lateral migration of the breast tissue. However, the current lingerie market predominantly revolves around bras designed for younger women that older women may feel are inappropriate for their physique. Literature regarding age-appropriate clothing has postulated that bras should be designed based on specific shapes, populations and usages. Yet the bra preferences of older women have been neglected in the literature. By determining women's requirements, the performance of current bras may be ascertained, and subsequent alterations may be recommended for bra design in order to optimise bras for older women if required. The aims of the current thesis were to: provide a wider understanding of the bra requirements of women aged 45 to 65 years, determine the key bra performance variables for this population, develop procedures to assess these variables and to determine the current appropriateness of a small sample of bras for this population. To achieve the research aims the thesis contained five studies. The first study was exploratory in nature, using focus groups and interviews to develop a knowledge base on the bra preferences of women aged 45 to 65 years. A survey was subsequently designed and implemented to determine the key bra performance variables among a wider sample of the population. The results of these studies identify the general dimensions that women consider when purchasing a bra (comfort, support, aesthetics, practicalities, and psychological aspects). From these dimensions, 11 key bra performance variables that are of importance to older women were derived (comfort, support, bra's ability to stay in place, appearance under clothes, silhouette, breast shape, breast lift, shoulder straps, discreetness, fabric and fit). Methods to quantify the key bra performance variables were required to assess the performance of current bras for older women. The third experimental study developed methods which minimised the limitations of existing procedures, and determined the validity and reliability of these methods. As a result of this study, methods to assess the 11 key bra performance variables were deemed acceptable for both objective and subjective measures. In the fourth study, two bras were selected from a popular and unpopular brand; the performance of these bras was assessed with regard to the 11 key bra performance variables. The results indicate that women aged 45 to 65 years preferred a bra that minimises breast kinematics, provides greater breast projection and lifts the breast sufficiently. Although differences lay between the bare breasted and bra conditions, the two bras performed similarly despite the difference in popularity. The final study incorporated a four week wearer trial to elucidate any changes in performance that may appear with increased usage. Subjective ratings of breast support and the bras' ability to stay in place were lower following the wearer trial. The bras tested performed well for the bra variables; comfort, fit, support and shoulder strap position. However, the remaining key bra performance variables may require alteration to ensure their appropriateness for women aged 45 to 65 years. It is concluded that women aged 45 to 65 years are generally cognisant of changes to their breasts as they age, subsequently seeking bras that are different from those they previously would have worn. The findings of this thesis suggest that alterations in bra design are required to optimise bras for older women.