Abstract Objective. To define phases of the sit-to-walk movement and test their consistency in a normal population. Design. An observational study of thirteen healthy volunteers. Background. Moving from sitting to walking is a daily activity that may present difficulty for some populations in terms of control and stability. Methods. The movement was partitioned into phases according to changes in ground reaction forces and peak velocity of the total body centre of mass. Consistency of each phase duration was assessed. Results. Four phases of sit-to-walk were defined; flexion momentum, extension, unloading and stance. ICC scores for phase duration ranged from 0.54 (extension) to 0.81 (stance). Conclusions. This is the first study to define distinct phases of the sit-to-walk movement. There was moderate to good consistency for phase duration. Relevance By defining and testing phases of the sit-to-walk movement this study enhances understanding of this everyday movement and provide a model for future research.