Provide is a health appliance and a method using the same which achieve active and appropriate assistance of bending of a knee joint. The health appliance, which allows a user lying or seated to move their knee joint while supporting the knee joint, includes a support 1 which is a triangular prism having one side surfaces as a bottom surface 11, and an aid 2 mounted on the leg below the knee and can be pulled by the user. The support 1 has a width W at which one knee is supported, and has a cross section forming a triangle with a base corresponding to one side surface 11 and an acute diagonal angle θ1. When sandwiched under the user's knee, the base angle θ2 adjacent to the toe is larger than the diagonal angle θ1 and smaller than the base angle θ3 adjacent to the thigh.