Real-time movement planning: A new model to describe human motor planning level

It has been shown that any movement that satisfies the minimum joint angle jerk constraint can be reproduced by linear combination of 6 consistent Movement Elements (MEs). In this work, we assumed that any given movement is consisted of several successive phases (without overlap) such that each phase satisfies the minimum joint angle jerk constraint. Based on this assumption, we have developed a new model to give a computational interpretation of the movement planning level of motor control system. In this model, any desired movement is planned using the MEs. Considering a critic at the higher level, we also enhanced the model so that it describes how at the movement planning level the desired movement is modified online. The two level of the model are evaluated by simulating the sit to stand (STS) transfer. The results indicate that this architecture can modify the planned movement with movement stability in view. In other words, the model explains how in the presence of unexpected disturbances the pattern of the movement is modified while the dynamic stability of the movement is maintained. We have also discussed the neurophysiological and behavioral basis of the proposed model.