Methods and therapeutic compounds for treating pain, mitigating inflammation, effecting analgesia andor effecting sedation in a subject are described. The roller unit includes a plurality of rollers and is positioned between the siderails and freely moveable between the pair of spaced chocks. The joint end portions of the first and second frame members each has circumferentially continuous first-fourth edges and the first-fourth edges are inclined when the joint end portions are viewed radially in any direction.