The purpose of this study is to examine the effect of mood phase on body movements of individuals with bipolar disorder. Assessment of body movements in individuals with mood disorders is important for diagnosis, but very few quantitative data exist on the effect of hypomanic, euthymic and depressed phases in bipolar disorder of mood on body movements. In this study, we asked healthy individuals and individuals with bipolar disorder to perform ordinary movements like walking and getting up out a chair. Movement data were collected using motion capture technology and force data were collected using force plates in the lab floor. Participants also completed questionnaires about their mood, and these data are compared with the biomechanical data to explore the relationship between mood phase and body movements. Individuals are tested twice, in sessions about six months apart, to determine if the effects of mood phase are the same over time. Outcomes of the study are important to assess whether body movements can be used as a biomarker of mood phase in individuals with bipolar disorder.