Quantifying body shape differences between supine and standing postures for adults with high body mass index
Authors: Monica L. H. Jones, Sheila M. Ebert, Jingwen Hu, Byoung-Keon Park, Matthew P. Reed
Approximately 34% of US adults are obese with a body mass index (BMI) greater than or equal to 30 kg/m2. This cohort is highly variable in body shape and in the amount of change in body shape with posture change. Three-dimensional surface scans provide a means of quantifying these differences. This study examined the change in surface shape of adults with high BMI between supine and standing postures. Supine postures are of particular interest because of the ready availability of medical imaging scans obtained in supine postures. Understanding shape change between supine and standing postures would enable the use of supine data for some standing applications.
Data were gathered from 12 adults (6 female and 6 male), ranging in BMI from 30 kg/m2 to over 40 kg/m2. Surface geometry in a standing posture was recorded in a whole-body scanner. A table with transparent support surfaces enabled supine whole-body body shape to be captured with a hand-held scanner. A grid pattern of landmarks on the participant’s torso was extracted from the scans to track surface deformation differences between the two postures. A least-squares alignment algorithm was employed to minimize the difference between standing and supine scan data.
The new methods provide high-resolution data on posture and surface geometry of individuals with a wide range of body shapes in both standing and supine postures. The ability to quantify the posture effects on body shape will enable geometries of adipose tissues extracted from medical images that are acquired in supine positions, to be applied to the external body shape. Data on body shape from a larger sample will be useful for improving product design and safety and provide more realistic computational surrogates.