Abstract: A physical therapy device for increasing lumbar spine extension range of motion, comprising a cylindrical rod for elastic material capable of repeated flexing without taking a set or deformation, and having its central patient-contacting portion covered by a cylinder of padding material. The roller thus formed is tethered to a treatment surface by a pair of straps or belts, each having one end attached to the treatment surface and the other attached by means of a snap ring and swivel to a ring carried by a collar on the extremities of the rod. The collars can be moved along the rod and secured where desired, to alter the force potential effective through varying the lever arm, and thus the amount the rod will flex. The ring is located in a portion of the collar having a reduced diameter and is free to rotate with respect to the collar and hence the roller.