Toward a Better Understanding of Coordination in Healthy and Poststroke Gait

Locomotor coordination characterizes healthy gait and rehabilitation effectiveness in poststroke individuals. However, despite a large number of clinic-based and laboratory-based measurement options, to date there is no gold standard for measurement of locomotor coordination. A lack of a common definition for locomotor coordination may be a cause of this confusion. Coordination during gait includes both spatial and temporal components that may be measured in extrinsic or intrinsic reference frames. Measurement tools have been used to evaluate one or both aspects of coordination. The authors suggest an operational definition of locomotor coordination and describe how current measures in healthy and poststroke individuals fit with this definition. They define locomotor coordination as an ability to maintain a context-dependent and phase-dependent cyclical relationship between different body segments or joints in both spatial and temporal domains. Advantages and disadvantages of laboratory-based measures, such as cyclograms, discrete and continuous relative phase, power spectral density, and others are summarized and discussed. In addition to the definition, the authors propose a clinically feasible measurement paradigm that accentuates the adaptive component of coordination and that may be useful in merging the clinical and laboratory-based approaches to locomotor coordination.