Predicting Reaching Postures Using a Kinematically Constrained Shoulder Model

We present a new muscle effort criteria for predicting physiologically accurate upper limb motion in human subjects based on skeletal kinematics, muscle routing kinematics, and muscle strength characteristics. The new criteria properly accounts for the cross-joint coupling associated with the routing kinematics of multi-articular muscles. We also employ a new kinematically constrained model of the human shoulder complex, which is critical for the proper evaluation of our muscle effort criteria. Through a set of subject trials we have shown good correlation between natural reaching postures and our proposed criteria.