A lower back exercise apparatus exercises or imparts laterally and upwardly directed movements into a user's lower back when seated thereupon. The lower back exercise apparatus includes a lower base assembly, an upper seat assembly, and a motor assembly. The lower base assembly includes an upper, laterally concave base surface. The upper seat assembly includes a lower, laterally convex seat surface and an upper seat surface. The upper seat assembly is laterally ridable upon and movable relative to the lower base assembly. The motor assembly is drives a laterally directed, cylindrical arc length trajectory of the upper seat assembly relative to the lower base assembly. The concave and convex surfacing have a common radius of curvature with a common fulcrum point spatially located adjacent an upper portion of a user's lumbar spinal region Lateral flexion is thus imparted into a user's lower back when a user is seated thereupon.