Auxiliary device fastened with a back massaging chair for enhancing massaging effect

摘要

An auxiliary device is used in conjunction with a back massaging device and is composed of a base, a movable seat, a plurality of crank axles, a plurality of roller sets, and a transmission apparatus. The base is provided with a plurality of compression springs to enable the movable seat, the crank axles, and the roller sets to swivel in all directions so as to bring about an effective rubbing of the curved portions of the back of a person. The movable seat is provided with an arcuate slot to prevent the vertebrate of the person from making contact with the movable seat.