Breast measurement and sizing

R Zheng; W Yu; J Fan

2.1 Introduction

The technical understanding of intimate apparel requires in-depth knowledge of human anthropometry and sizing. To achieve an accurate fit of second-skin intimate apparel, in particular bras, detailed body measurements are necessary for the definitions of body shape, curve profile and dimensions of the torso, especially for the breast region. Fan, Yu and Hunter have authored a research monograph [1] published by Woodhead Publishing Limited that critically reviewed various research works on body measurements, sizing systems and body beauty in general. However, there was limited literature found that related to body sizing for intimate apparel.

2.2 Measurement of breast dimensions

In order to obtain accurate measurements for the upper torso and the breasts, it is important to control the human subject's posture, clothing and body landmarks, as well as carefully selecting the measuring devices and relevant measurement items.

2.2.1 Control of posture and clothing

Similar to the general body measurements, accuracy is also affected by the clothing worn by the human subject, his/her breathing and posture. Bra size is even more difficult to measure because the natural breasts may tend to drop low and spread wide. Historically, bra tailors asked the model to take off her bra and lift her breasts to where she wants the bra to fit. Then at that level, the measurement was taken by tape measure. However, the determination of desirable breast position varied from one person to another and from time to time.

The international standards of breast dimensions, ISO 8559 [2] suggests measuring over a well-fitted, unpadded and thin brassiere with minimumaccessories and support. ISO 7250 [3] specifies the body measuring procedures based on a nude subject who is wearing minimal clothing and no shoes, standing fully erect with feet together, head in the Frankfurt plane1 and shoulders relaxed with arms hanging freely during the standing position measurements. ISO/DIS 20685 [4] recommends three standing positions for various 3D body scanners to obtain reliable data. It was suggested that during the 3D body scanning, measurements should be taken during the subject's quiet respiration; the shoulders should be straight, being natural with relaxed muscles. The first author, Zheng previously chaired the Aimer Human Engineering Research Centre of the Beijing university of Clothing Technology (AIMER HEC-BUCT). The centre adopted the following procedures to ensure that subjects stood erect during the manual measuring (see Fig. 2.1). Thesubject was asked to wear only a close-fitting panty and no bra, to stand erect with bared heels together and feet open at an angle of about 30 degrees, then look straight ahead with arms hanging naturally. In order to obtain more reliable data for 3D scanning, the posture was changed with the heels splayed to about 100–150 mm and the upper arms held apart from the sides of the torso at an angle of 15–20 degrees.

2.2.2 Body landmarks

In the collection of anthropometric data, the identification of body landmarks is the first key step to prevent operational errors in handling the measuring device and determination of the body position. By definition, a body landmark is an anatomical feature used as a point of reference to locate body features for measurements [6]. International Standards identify only the common anthropometric measurement points and lines for the sizing of general clothing, but more detailed points and lines are needed for meaningful measurements of the breast size and shape.

Anthropometric measuring points for landmarking

In addition to the traditional methods of making body landmarks [7], Zheng [8] has developed additional measuring points, based on the subcutaneous bone framework of the human body related to the breast measurements. The specific points are shown in Fig. 2.2 and defined in Table 2.1.

All the anthropometric measurement points should be marked on the skin with a non-smearing pencil [12] or skin-safe washable ink [16] before the actual breast manual measurements. Furthermore, for 3D scanning purposes it is recommended that special raised stickers [17] be used to mark the keylandmark locations on the subject to ensure the measuring points can be found. In the applications of 3D body scanners, it is also important to establish landmarks so that the data automatically obtained and calculated can be widely understood and used by various industries. Simmons and Istook [18] compared the common body-scanners [TC]2, Cyberware, and SYMCAD with traditional manual anthropometric methods. They found that measuring techniques varied among different scanners. It was impossible to use the current standards to determine the measuring process in 3D scanning. Using such non-contact methods, absolute identification of landmarks could not be satisfactorily achieved automatically.

From the CAESAR anthropometric survey, Robinette and Daanen [17] found that the automatic landmarking methods for 3D body scanners did not work consistently enough on all body types. Even using neural networks or other automated recognition packages to identify the landmark location of the stickers, it seemed to be successful for only 70% of the measurements. They considered that manual intervention for validation and verification of the landmark locations on all subjects was still required.

Anthropometric measuring lines for landmarking

The common body measuring lines are well known by anthropometrists and their definitions are shown in Fig. 2.3 and Table 2.2. Tailors and researchers normally use tape measures to record the body circumference at a specific body height. However, it can be difficult to ensure data accuracy because the measuring tape might not be exactly horizontal and in a plane parallel to the ground.