ABSTRACT
BACKGROUND:Differences exist between the action execution of the dominant hand and the nondominant hand during daily lives. With the increasing of the age, the dominant hand and the nondominant hand play an equaly important role in the action execution and implementation during daily lives. Previous studies mainly focus on the muscle strength of upper limbs. However, studies on the influence of joint dynamic characteristics and trajectory deviation on the occupational activities have been increased gradualy. The three-dimension motion capture and analysis have become the reliable and valid standard of the assessment of the upper limb movement. OBJECTIVE:By using the three-dimensional kinematic analyze method, to colect the data of the healthy elderly people using the upper limbs to drink water respectively with the cups of different weights and to investigate whether there is a difference between dominant and nondominant hands under different weight-bearing conditions based on upper limb kinematics METHODS: Sixteen right-handed elder people were chosen to be the experimental subjects. The upper limb motion of drinking water with different weight was captured by Vicon Nexus. By Data modeling and trajectory filtering with pipeline and data normalizing with the Matlab, the three-dimensional angle and peak value of the velocity of the should, elbow and wrist joint in the bilateral upper limbs were analyzed and compared when lifting the cups of 100, 200 and 500 g. RESULTS AND CONCLUSION:The most significant difference could be found in the three-dimensional movement angle of the elbow joint when holding the weights: there were significant differences in 100 g horizontal plane (X axis) and sagittal plane (Z axis), 200 g frontal plane (Y axis) and sagittal plane (Z axis), and 500 g three-dimensional plane (P 0.05). These results show that there is a difference in the movement angle and angular velocity between the dominant hand and the nondominant hand when drinking water. A great change of movement angle could be found in the X axis of the elbow joint in the dominant hand, and a great change of the movement angle could be found in the Z axis of the elbow joint in the nondominant hand. The angluar velocity in the Y axis has better changes than in the Z axis. The size of the weights has no effect on the movement of bilateral upper limbs.