Cultivating Functional Variability: The Dynamical-Systems Approach to Rehabilitation

based on the environmental cues received as the task is performed. If there are changes in the task or environment, the sensorimotor system can organize a new strategy to satisfy demands associated with the movement goal. More strategies translate to an enhanced ability to successfully accomplish the movement goal and cope with change. This has been referred to as invariant results through variant means, which is also referred to as functional variability.2 Injury can significantly hinder the sensorimotor system in its ability to UNCTIONAL REHABILITATION associated with physical activity has been touted to be the cornerstone of athletic training’s niche among health care professions. This rehabilitation paradigm has focused on restoring sensorimotor function related to sport/ activity-specific rehabilitation exercises and equipment. Advances in techniques associated with this paradigm have brought forth such things as jump training programs for the prevention of ACL injuries in female athletes and balance training for those with chronic ankle instability. As the utilization of these programs become more widespread, the need for a theoretic construct to aid in decisions associated with program design, evaluation, and progression has grown. The dynamical systems theory (DST) provides such a framework. A previous ATT report introduced DST as it relates to sports medicine research.1 According to DST, the behavior of the sensorimotor system is controlled by (a) the health of the person, (b) the task being performed, and (c) the environment in which a movement goal is executed (Table 1). Rather than having preprogrammed neural pathways to accomplish a movement goal (associated with traditional theories of sensorimotor system function), DST suggests that the sensorimotor system is free to develop and change strategies as it interacts with the environment. In this way, coordination within the sensorimotor system changes on the basis of demands imposed by the movement goal. Because of this spontaneous (goal-oriented) self-organization, a healthy sensorimotor system can accomplish a movement goal in a variety of ways, any one of which is John Parsons, MS, ATC, AT/L, Report Editor