Assessing the Influence of Sensory Interaction on Balance

Assessment of standing balance is essential to the treatment of instability in the neurologic patient. The development of clinical techniques for evaluating instability is dependent on a thorough understanding of sensory and motor processes underlying normal balance control. Motor processes in balance control coordinate the action of trunk and leg muscles into discrete synergies that minimize sway and maintain the body's center of mass within its base of support.1,2 Sensory processes in balance control involve interaction among orientation inputs from somatosensory (proprioceptive, cutaneous, and joint), visual, and vestibular systems. Despite the availability of multiple sensory inputs, the central nervous system generally relies on only one sense at a time for orientation information.3 For healthy adults, the preferred sensory input for the control of balance is somatosensory information from the feet in contact with the support surface.