Abstract: A device is provided for exercising the muscles of the back, which includes a chair seat and a rod fastened to a feet plate. The feet plate is coupled to a tilting member which is surrounded by a damping member. The damping member can rest on a bottom plate which is fastened by a fastening member. A cloth which surrounds the damping member and is fastened to the feet plate can replace the bottom plate and the fastening member. It is further an advantage that the rod is telescopic. The tilting member can have a circular cross section and a downwardly conical form. The damping member which surrounds the tilting member is of a flexible material and may be fastened to the feet plate by the fastening means member which can assist in dampening the movement of the tilting member.