Kinematics analysis of chopsticks manipulation

Chopsticks are widely used in the Oriental countries. However, people develop their personal holding postures. Two main postures can be identified. One is parallel type, the other is crossed type. The purpose of this study is to compare the kinematics performance in these two holding postures, furthermore, to find out the reasons why the parallel type seems to be more effortless than the crossed type. seems to be more effortless than the crossed type. Eleven participants were recruited in this study. Six were parallel type, and the others were crossed type. They were asked to manipulate chopsticks in upper and lower positions. The kinematics parameters, including the finger joint flexionextension angle, the digit-to-digit abduction angle, the finger relative flexion-extension angle, the wrist joint flexionextension angle as well as radial-ulnar deviation angle, the chopsticks angle, the chopsticks tip distance and the velocity of approaching movement were measured. Whole duration was divided by four time points for a clear comparison. The results in significance showed that the chopsticks angle was greater in crossed group than in parallel group. Besides, in comparing with crossed group, participants in parallel type seemed to change their movement pattern more often or with more variability. For the future study, a detailed classification of manipulation patterns should be clarified according to the high variability within two current types. After all, this study has revealed some difference between manipulation patterns in kinematics way. More biomechanics significance needs to be addressed in the future.