ABSTRACT
Objective To investigate effects of cold water stimulation on kinematic and dynamic characteristics of index finger. Method In order to reduce the influence on its flexion and extension, the index finger movement was recorded by a high speed camera. Then a self developed MATLAB program was developed to obtain the trajectory with the help of the black speckles on index finger joints. Finally, a dynamic calculating model with FDS and FDP was set up to describe the relationship between the trajectory and muscle forces changed along with the time. Results After the cold water stimulation, the average angular velocity of the second joint in the index finger decreased in the process of fisting and stretching. Before and after the cold water stimulation, the force of FDP muscle changed little while the force of FDS muscle approximately doubled at the end of the fisting. Conclusions An optical method for obtaining the trajectory of index finger was applied, and a dynamic calculating model was developed to calculate the muscle forces during the finger movement. Therefore, the characteristics of the index finger before and after the cold stimulation could be further discussed.