sit-to-stand (STS), 1. in the treatment of balance disorders, a movement in which the base of support is transferred from the seat to the feet. The feet begin to accept the weight first by downward pressure through the heels as the pelvis rolls anteriorly. The weight then moves to the front of the feet as the trunk moves forward and the pelvis lifts from the surface. 2. a transfer activity in which a patient moves from sitting to standing.
