In this project we investigate the contribution of the passive viscoelastic component that comes from the musculotendon structure in the hand during the coordinated wrist and hand movements.

First we have carried out a system identification experiment to determine a model of finger joint stiffness as a function of finger and wrist configurations. Our studies of dynamic coordinated motion of the finger and wrist show that the passive viscoelastic component is dominant over dynamic coupling terms. It is interesting to note that for the coordinated shoulder and arm movements it has been shown that the dynamic coupling terms dominate over the viscoelastic components.

We believe that the nervous system must have a good model of the biomechanics in controlling the hand, and the multi-coupled-joint hand structure may have simpler control strategy due to the dominant musculotendon passive structure.