Abstract: A portable therapeutic seat exercise apparatus and method that provide a lightweight personal exerciser designed for a person to use to improve physical status, and for the exercise, alignment, and stress reduction of a person's trunk, spine, abdomen, pelvis, and thighs. It encourages and enhances low back mobility in contrast to the static nature of regular sitting. It consists of a lightweight contoured seating surface supported by at least one arcuate hemispherical base that allows unrestricted motion in all directions, including twisting, tilting, and rocking. It can be placed on many seating surfaces including but not limited to sofas, dining chairs, school desk chairs, office chairs, factory benches, and motor vehicle seats. Its use facilitates low back muscular stabilization, conditioning, strengthening, coordination, and enhancement of proprioceptive senses.