A DYNAMIC VIRTUAL HAND MODEL FOR ESTIMATING JOINT TORQUES DURING THE WRIST AND FINGERS MOVEMENTS

Abstract

Determining the dynamic properties of the joints of human limbs is a control and design parameter for humanoid mechanism, rehabilitation robots and orthotic and prosthetic devices. In other researches, some methods have been suggested for estimating joint torques of the hand such as mathematical models and simulation models. A 16 degree of freedom (DOF) dynamic simulation model of an average human hand is suggested in this study. Dynamic model of a human hand has been created by SimMechanics on MATLAB. Abduction/adduction and flexion/extension motions of the wrist and the fingers can be analysed using SimMechanics model by changing joint rotation. The model has been analyzed by inverse dynamics method using the video record of five healthy subjects (31.2 ±9.57 years) and the joint torques of the wrist and fingers have been calculated. The greatest torque of index finger with 0.0149 Nm occurs at the MCP joint during the cylindrical grip. The greatest wrist torque has been calculated as 0.225 Nm during motion of flexion/extension. Our results are similar to previous works. This simulation model can be used for estimating the joint torques at different motions of the hand without external devices and mathematical techniques.

Keywords

• Biomechanical model
• Joint torque
• Virtual hand.