Kinematical analysis of the linkage of the index finger on the basis of the posture measurement.

本研究的目的是研究食指的运动学参数（即连杆的长度，DIP关节角度和PIP关节角度之间的配合）如何影响食指尖端的可操控性。采用三维体位测量法测量了20例22 ~ 25岁受试者的食指屈伸度。利用测量数据建立了拇指和食指尖捏位时食指联动的运动学模型。利用三维测量方法获得了食指DIP关节角和PIP关节角在屈伸时的配合度。利用食指的运动学模型，结合DIP关节角度和PIP关节角度的配合，得到了指尖-捏位时指尖速度到关节角速度的变换。利用Mo . More ore Penrose逆矩阵代替DIP关节角和PIP关节角的配合，我们得到了指尖速度到关节角速度的变换。在拇指和食指的三种指尖捏捏姿势中，比较了DIP关节角度和PIP关节角度协同得到的指尖速度到关节角速度的变换与Moore Penrose逆矩阵得到的变换。本研究测量的20名受试者的链接长度的平均比值为：（指尖到DIP关节轴的距离）：（DIP关节轴到PIP关节轴的距离）：（PIP关节轴到MP关节轴的距离）=2.7:2.5:4.8。DIP关节角与PIP关节角的配合关系用平缓的s型曲线表示。在DIP关节角和PIP关节角协同作用下，指尖速度到关节角速度的变换与Moore-Penrose逆矩阵的变换非常相似。在结论中发现，确定了食指的运动学参数，从而可以通过运动中最小角速度的输入来控制指尖的运动。少

The purpose of the present study is to investigate how the kinematic parameters of the index finger (i.e. the length of the link, and the cooperation between the DIP joint angle and the PIP joint angle) influence the manipulability of the tip of the index finger. The flexion and extension of the index fingers of twenty subjects who were 22-25 years old were measured using a three dimensional position measurement method. The kinematic model of the linkage of the index finger in the tip pinch posture of the thumb and index finger was developed using the measurement data. The cooperation between the DIP joint angle and PIP joint angle of the index finger in the flexion and extension was also obtained using the three dimensional measurement method. The transformation from the finger tip velocity to the joint angular velocities in the tip-pinch posture was obtained using the kinematic model of the index finger and the cooperation between the DIP joint angle and PIP joint angle. Using the Mo … More ore Penrose inverse matrix instead of the cooperation between the DIP joint angle and PIP joint angle enabled us to obtain the transformation from the finger tip velocity to the joint angular velocities. In three tip-pinch postures of the thumb and index finger, the transformation from the finger tip velocity to the joint angular velocities obtained from the cooperation between the DIP joint angle and PIP joint angle was compared with the one obtained from the Moore Penrose inverse matrix. The average ratio of the link lengths of twenty subjects measured in this study was as follows; (the distance between the tip of the finger and the DIP joint axis ):(the distance between the DIP joint axis and the PIP joint axis):(the distance between the PIP joint axis and the MP joint axis)=2.7:2.5:4.8. The cooperation between the DIP joint angle and the PIP joint angle was represented by a gentle sigmoid curve. The transformation from the velocity of the finger tip to the joint angular velocities with the cooperation between the DIP joint angle and the PIP joint angle was very similar to the one with the Moore-Penrose inverse matrix. In the conclusion, it was found that the kinematic parameters of the index finger were determined so that the motion of the finger tip could be controlled by the input of the angular velocities whose magnitude was the minimum in motion. Less