Progress in locomotor rehabilitation has created an increasing need to understand the factors that contribute to motor behavior, to determine whether these factors are modifiable, and if so, to determine how best to modify them in a way that promotes improved function. Currently available clinical measures do not have the capacity to distinguish between neuromotor recovery and compensation for impaired underlying body structure/functions. This Special Interest article examines the state of outcomes measurement in physical therapy in regard to locomotor rehabilitation, and suggests approaches that may improve assessment of recovery and clinical decision-making capabilities. We examine historical approaches to measurement of locomotor rehabilitation outcomes, including rating scales, timed movement tasks, and laboratory-based outcome measures, and we discuss the emerging use of portable technology to assess walking in a free-living environment. The ability to accurately measure outcomes of rehabilitation, both in and away from the clinical/laboratory setting, allows assessment of skill acquisition, retention, and long-term carryover in a variety of environments. Accurate measurement allows behavioral changes to be observed, and assessments to be made, regarding an individual's ability to adapt during interventions and to incorporate new skills into real-world behaviors. The result of such an approach to assessment may be that interventions truly translate from clinical/laboratory to real-world environments. Future locomotor measurement tools must be based on a theoretical framework that can guide their use to accurately quantify treatment effects and provide a basis upon which to develop and refine therapeutic interventions.