Figure 1.

To enable simulation of combined wrist and finger motions, (a) the kinematic tree of the dynamic model described in Saul et al. (2015) was augmented to (b) include the degrees of freedom and kinematics of the fingers, thumb, and carpal-metacarpal joints. Location of the colored spheres represent the location of center of mass of each individual segment in the distal upper limb within the original model (Saul et al., 2015) and the adapted model; the diameter of each sphere indicates the mass of the modeled segment (see Table 1). Red lines represent simulated muscle-tendon paths within the model; for the purposes of this study, we only included the extrinsic muscles of the index finger.