Rotation lower back with stability ball

Rotate the torso under control through the rib cage and waist while keeping the pelvis as stable as the variation allows. Return without bouncing. Use a steady tempo: control the return phase in particular and avoid relying on momentum. Exhale through the hardest part and inhale as you recover the starting position.

Check that the movement stays stable in both directions and that the torso is not compensating. The goal is controlled loading of lower back; match resistance and range to a beginner level and never force a painful repetition. On unstable surfaces, master the position with light resistance first; stability should limit difficulty before load does.