Sports bra optimization by Finite Element simulation of interaction between textile and female breast tissue (FEM-Sports-Bra)

This is a cooperative research project funded by Vienna Business Agency within their call FemPower 2015. Lead partner is the company CAE Simulation & Solutions Maschinenbau Ingenieurdienstleistungen GmbH(www.cae-sim-sol.at), duration is 22 months (7th January 2016 to 31st October 2017).

Studies have shown that every fifth woman aged 18 to 65 doesn’t do any sports because she feels disturbed by the movements of her breasts (Burnett, White & Scurr, 2015). Sportswear manufacturers have developed different sports bras to support the breasts from below and to reduce the amplitudes of breast movements. As these bras constrict at bust girth or straps, comfort is evaluated as unsatisfactory and 59 percent of women wear an everyday bra when doing sports (Bowles, Steele & Munro, 2008). Studies confirm that the vertical movement amplitudes of female breasts (cup size D) are up to 8 cm, which are reduced by only 2 cm when wearing a commercial sports bra (Scurr, White & Hedger, 2011). Running and jumping movements create an out of phase motion of the breast due to the elastic connection between breast and thorax. The upward breast movement is described as much more discomforting than the downward movement and it is still an insufficiently solved problem.

The arising research questions are:

•             Which (constructional) changes of sports bras provide a reduction of upward breast movement without a reduction of wearing comfort?

•             How can a scientifically based and evaluated model contribute to a more objective individual adaptation of sports bras?

The sample shall consist of 50 women aged 15 to 60 with different breast shapes and sizes ranging from 75B to 90D. Shape and volume of breast tissue are determined using 3D surface scans providing the geometry for a finite element (FE) volume model consisting of a rigid thorax, two flexible breasts and skin. The dynamic behavior of the breast in combination with textile fabric shall be analyzed performing 3D movement recordings using marker set and VICON system. Participants will run on a treadmill at predefined speeds without and with two different bras. Combining the results of these two measurement methods, FE models of thorax, breasts and bra can be created and validated.

Based on the scientifically evaluated model, additional straps and reinforcing elements for a more efficient bra shall be modeled. Simulation results provide recommendations for prototype construction, either in the sense of standard sizes for various breast shapes or of an individual adaptation. Subsequently, cooperation with a renowned sportswear company is intended, implementing the findings gained within this project.

Project leader: Michaela Haßmann MSc / FEM-Sport-BH@univie.ac.at

References:

Burnett, E., White, J. & Scurr, J. (2015). The influence of the breast on physical activity participation in females. Journal of Physical Activity & Health, 12 (4), 588–594. doi: 10.1123/jpah.2013-0236

Bowles, K.-A., Steele, J. R. & Munro, B. J. (2008). What are the breast support choices of Australian women during physical activity? British Journal of Sports Medicine, 42 (8), 670–673. doi: 10.1136/bjsm.2008.046219

Scurr, J. C., White, J. L. & Hedger, W. (2011). Supported and unsupported breast displacement in three dimensions across treadmill activity levels. Journal of Sports Sciences, 29 (1), 55–61. doi: 10.1080/02640414.2010.521944