Motor control, excitement, and overarm throwing.

Although motor control has historically been an important discipline, it runs the risk of being overshadowed by other newer areas of neuroscience. One response would be to generate increased excitement in motor control, e.g., by more clearly defining the big questions, by discussing them in new audience-friendly formats, and by promoting them, perhaps in the context of applied motor control. One recent exciting development has been a shift to the study of natural multijoint movements in three dimensions. We are currently investigating one such multijoint movement, overarm throwing. The question we are asking is, What causes inaccuracies in overarm throws? Is it errors in the timing or in the velocity of joint rotations that produce the hand trajectory? Surprisingly, inaccuracies (high and low throws) do not result from errors in rotations of proximal joints; instead they result from variability in the timing of onset of finger opening. It remains to be determined whether the decreased accuracy in throwing in cerebellar patients is caused by an increase in this error or from disorder in some other multijoint coordinating mechanism.