Analysis of head motions during food intake in Japanese adults using a new motion capture system

Objective: A new motion capture system was developed to verify the hypothesis that "during food intake, head motion changes according to the properties of the food." Design: Twenty healthy males and 20 healthy females with right-handed and normal occlusion participated in this study. The motion capture system used consisted of a Microsoft Xbox One Kinect Sensor (R) and a newlydeveloped program. Meatballs (solid), yogurt (paste), and water (fluid) were used as food samples. Head motion distance, head turning angle, and head forward angle were measured during food intake. Unpaired t-tests were used to analyze each head motion and compare the sexes. A one-way repeated measures analysis of variance was used to analyze each head motion for different food samples. Results: Head motion distance was significantly smaller in females for the meatball and yogurt, but not for water. There were no significant differences between the sexes for head turning angle or head forward angle. Head motion distance and head forward angle were significantly larger for water than for meatballs and yogurt. The head turning angle was significantly smaller for the meatball than for yogurt and water. Conclusions: The results indicated that females tend to consume food without moving their heads when eating solid and paste foods. As the fluidity of the food increased, the head moved in a turning motion to avoid spilling the food, and the heads tilted forward. The motion capture system used in this study was also effective in analyzing head motion during eating.