Solution space: Monitoring the dynamics of motor rehabilitation

This article presents and discusses a perspective on the concept of "solution space" in physiotherapy. The model is illustrated with a subjective assessment of the way movements are performed and an objective quantification of the dynamics of the recovery process for a patient with a knee injury. Based on insights from the domain of human motor control, solution space is a key concept in our recovery model that explains the emergence of a variety of adaptive changes that may occur in the movement system recovering from an injury. The three dimensions that span the solution space are: (1) information and control processes; (2) time; and (3) degrees of freedom. Each dimension is discussed within the context of feasible physiotherapeutic assessments to identify and facilitate desirable behavioral patterns or bypass emerging but undesirable behavioral patterns that could impede both short- and long-term recovery. Central to this article is our view on the relationship between the recovery process and the three dimensions of the solution space, which determines the model's usefulness as a motor-rehabilitation monitoring tool.