目的 考察冷刺激对食指运动学及动力学特性的影响。方法 为减少对食指屈伸的影响，采用高速摄影仪记录食指屈伸运动过程的方法，记录食指在自然状态和冷水刺激两种情况下的屈伸运动，通过自行编写的程序对视频文件进行处理，得到食指各关节角度随时间的变化，最后通过一个包含两块肌肉（FDS: flexor digitorum superficialis，FDP: flexor digitorum profundus）的肌骨骼模型计算得到肌肉力随时间的变化关系。结果 冷水刺激后，食指第二关节在屈伸过程中的平均角速度变小。冷水刺激前后，FDP肌肉力没有太大的变化，而FDS肌肉力在弯曲结束时增加了1倍左右。结论 本文通过影像结合图像处理的方式得到了食指在屈伸过程中的轨迹信息，并通过简化建立了连接食指表观信息与内部肌肉力的计算模型，进一步讨论了冷水刺激前后食指的运动学和动力学特性。

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.