An understanding and clear descriptions of the human body in motion is important to achieve good fit of garments (Bye et al, 2006; Gill, 2009). However, to date there is still limited research on measuring the dynamic body and its application to clothing, and no previous studies have focused on measuring the dynamic body across body sizes.
The purpose of the research was to explore the research method to examine body measurements using the motion capture system. This study tested the accuracy and reliability of a motion capture system in measuring a human body in comparison to the 3D body scanner. The second purpose was to investigate the body measurement changes in motion and to examine the measurement changes in motion across body sizes.
The exploratory research was developed based on the framework for micro and macro levels of fit. The methods for this study were developed to examine body measurements using a motion capture system. The upper body movements in relation to the shoulder girdle were selected for a motion test for this study. The selected motions were the arm rotation and golf swing. Measurements were selected based on their application to pattern development.
A total of the 25 women participated in this study. All of them participated in the golf swing test; six were the golf team members and 19 were novices. Of the 25 participants, 19 participated in the arm rotation test. Markers, needed for the optical motion tracking system, were placed at locations on the body corresponding to the selected measurements. Once the markers were attached, the participants were scanned in a natural and relaxed posture using the body scanner, and then their movements were recorded three times using a motion capture system. The quantitative data from the body scanner and motion capture system were analyzed using descriptive statistics, a paired t-test, and an independent t-test.
Descriptive analysis of the body measurement change in the two different motion tests in this study indicated that upper body measurements increased or decreased corresponding to the shoulder joint and scapula movement. The shoulder and back arc at the armpit showed the greatest measurement change. The back arc at the armpit increased the most, while the shoulder width decreased the most in the upper body during the motion that involved the arm and torso movement. When the participants performed the arm rotation motion, the shoulder width (-38.45%), back width (16.08%), and back arc at the armpit (27.69%) showed the most change. The locations that changed measurements the most were the same as the results from the golf swing test. When the participants performed the golf swing motion, the shoulder width (-14.47%), back width (15.58%), and back arc at the armpit (20.65%) changed the most. An independent t-test indicated that the measurement changes in the golf swing test were different between the novice and expert golfers due to their golf swing poses. There was a significant difference in the decreases of the shoulder width, and the increases of the lower back arc, right side length, and left diagonal on the back of the body.
The results of this study suggest that the measurement changes and percent changes increased as body size increased in two different motion tests.
This study suggests that the motion capture system can be successfully used as a body measurement method. The motion capture system can be a reliable method to collect body measurements and to examine the body measurement changes in motion. The motion capture system allowed considering variations in continuous movements among individuals across sizes for dynamic anthropometric studies.