Multidimensional Analysis of Head Stabilization-Progress and Prospects

The ultimate objective in studying the vestibulocollic (VCR) and cervicocollic (CCR) reflexes is to understand their dynamic and spatial properties at three levels: the kinetics of movement of the head, neck vertebrae, and neck muscles following perturbation of the body in any direction; the dynamics of activation of each class of receptor and each neck muscle; and spatial and dynamic properties of neuronal circuits that transform receptor input to muscle output. Current progress and future prospects for understanding each of these aspects are summarized. Three-dimensional power spectral characteristics of movements of the head-neck system have been measured during functional activities. Significant power was observed in the pitch and yaw planes, with the wider bandwidth for pitch occurring for walking in place.