Breathing Cycle and Posture Affect Magnitude and Anatomic Measurement Site of Waist Girth in Healthy Adults: An Insight from 3D Scanning

Waist girth is widely accepted as a simple anthropometric indicator of metabolic and cardiovascular disease risks. The aim of this research is to evaluate the impact of breathing cycle on the magnitude and anatomic measurement sites for waist girth using Hamamatsu 3D scanning. A sample of healthy adult volunteers (75 males and 36 females; age 27.8±7.5y and 23.6±4.2y respectively) participated in the study. Each wore form-fitting clothing (a swim cap, swimwear or lycra shorts and a sports top for women) which exposed the waist region. Each participant was scanned using a Hamamatsu BLS 9036 fixed scanner (Hamamatsu Photonics, UK) in three different phases of breathing cycle: end tidal (T), inspired (I) and expired (E); and in a scanner posture (SP) with arms and legs abducted. Acquired scans were analysed using the system’s software (Body Line Manager Version 1.3). The effect of the breathing cycle on waist girth had the highest mean value at T (72.0 and 83.9 cm) in females and males, respectively and least mean value at E (70.9 for female and 81.9 cm for male). Adopting the scanner position resulted in a mean value of 70.5 cm and 82.9 cm for female and male respectively. At I, breathing cycle also altered waist girth significantly from the value obtained at end tidal (P<0.05) in females but yielded no difference in males (P>0.05). The anatomic measurement site for minimum waist girth had the highest vertical location at E (115.0 and 106.4 cm) for male and female respectively, the least at I (112.9 and 105.0 cm) for males and females respectively (P<0.05). In the scanner position end tidal the height level was at 114.7 cm and 105.1 cm for males and females, respectively. Breathing cycle and posture affect measurement value and anatomic measurement site of waist girth.