Abstract: An exercise device for strengthening muscles used in horseback riding includes a handle and a base having opposed surfaces. An elongated arm has a joint between a first and a second section. The first section is affixed to the handle at an outer end, and the second section is affixed to the base at an outer end. The joint permits angular movement between the first and the second section in a plane generally parallel to planes defined by the base surfaces. The first and the second section are bendable between a first and a more-acute second angle. In use, a user lies substantially prone and grasps the handle, places one heel against each of the base surfaces, and draws the base toward his/her trunk using heel pressure, thereby bending the arm from the first angle to the second angle.