Abstract: Single function evaluation on bras does not cater for women's comprehensive requirements for sports bras during exercise. Although comprehensive evaluations on thermal function of bras have been documented, breast movement reduction and dynamic pressure comfort, as two of the most representative functions of sports bras, have not been reported to be included into the comprehensive evaluation on sports bra function. This study aimed to explore a comprehensive evaluation method for sports bra functions. A subjective evaluation experiment was also conducted to verify the validity and feasibility of the results.
Taking function as the starting point, the article established a comprehensive evaluation system for the function of sports bras by considering the shock-proof function, pressure comfort and heat and humidity comfort of sports bras and choosing the four representative indexes of displacement, pressure, air permeability and moisture permeability, respectively. The experimental subjects were five C-cup women, and the experimental samples were seven sports bras. The subjects wore the seven sports bras in turn and ran on the treadmill at 7.5 km/h and 10.0 km/h respectively. The vertical breast displacement and cup pressure during running were collected and calculated, and the air permeability and moisture permeability of two cushions of each bra were tested.  Entropy method and variation coefficient method were employed to calculate the weights of various indicators, subsequently deriving comprehensive evaluation values for the seven samples of sports bras. Finally, the feasibility and effectiveness of the objective weighting method in assessing the functionality of sports bras were validated through subjective evaluation experiments.
Comprehensive evaluation method for sports bra function used in this study could be categorized into six key steps, which were determining representative parameters, collecting parameter data, normalizing collected data, calculating weight coefficient of each parameter, calculating comprehensive evaluation score for each bra sample and ranking bra samples according to comprehensive evaluation scores. The results show that the weights of each index obtained by the two methods are consistent when the speed of movement is 10.0 km/h. Through the test of the data of each index of the seven samples, it is found that the air permeability and moisture permeability of sample clothing 2# are the best, and the displacement is second only to sample clothing 1#; the displacement, pressure and moisture permeability of sample 7# are the worst. According to the comprehensive evaluation of the functional performance of the sports bra, the comprehensive rankings obtained by the entropy method and the coefficient of variation method are consistent with the order of superiority being 2#, 1#, 4#, 3#, 6#, 5#, and 7#. In addition, in the subjective validation experiment, the subjective evaluation results are in agreement with the two objective evaluation ranking results to a large extent. The validity and accuracy of the two comprehensive evaluation methods are demonstrated.
This study provides two new objective weighting methods for synthetical assessment of sports bra function. Both the entropy method and variation coefficient method can obtain comprehensive evaluation scores of sports bra function. The evaluation results of the two objective weighting methods under the two running speed conditions are consistent, and the overall ranking of each sports bra is relatively stable. The results of objective evaluation and subjective evaluation are consistent to a large extent, which verifies the feasibility of the comprehensive evaluation method of sports bra function based on the objective weighting method. This finding confirms the notion that the objective weighting method is a scientific and rational method to evaluate sports bra function synthetically, which effectively avoids the interference of subjective factors and provides a new direction for product evaluation and optimization.

Key words: sports bra, function, comprehensive evaluation, entropy method, variation coefficient method, object weighting method

摘要： 运动文胸是女性参与体育锻炼最重要的装备之一，其功能性优劣直接影响女性运动者的运动表现和乳房健康。为了全面评价运动文胸的功能性，从运动文胸的防震功能、压力舒适性和热湿舒适性方面考虑，建立运动文胸功能性综合评价体系。采用熵值法和变异系数法两种客观赋权法对7款运动文胸的功能性进行综合评价，并通过主观评价实验验证结果的可行性和有效性。结果表明：熵值法和变异系数法这两种客观赋权法得到的综合评价一致，且与主观评价实验的结果一致程度较高，验证了使用这两种客观赋权法对运动文胸功能性进行综合评价具备可行性。文章采用的两种客观赋权法为运动文胸的综合评价提供了一定参考，同时也为文胸的质量评估提供了思路。

关键词: 运动文胸, 功能性, 综合评价, 熵值法, 变异系数法, 客观赋权法