Abstract: The present invention provides a dynamic chair having a deterministic motion path that allows a variety to different paths to be selected depending of needs of user. By changing the ratio between drive wheels that control the pitch and roll of the seat, motion paths can be selected to help a person assume and/or avoid certain postures while seated. Embodiments of the present invention move the seat of the dynamic chair through a deterministic path to dictate how often and when the seat is in a level position with respect to pitch and roll.