A dynamic stretching, strengthening and stabilization device is provided for postural correction and retraining. The device has a pair of closed loop resistance tubes and a central harness member which positions the closed loop resistance tubes roughly in the form of a FIG. 8. Each loop of the resistance tube is sized to accommodate the arm and shoulder of the user. The device may be used in a stabilization mode or stretching/strengthening mode, and transitions easily between these modes to correct and retrain the user's posture.