Abstract: The present invention provides an adjustment structure of the chair backrest. The adjustment structure includes a sliding end of the first part of the backrest, and the guiding sliding seat of the second part of the chair backrest. A positioning component is placed on the pre-determined part of the guided sliding seat and on the assembled part of the positioning component of the guided sliding seat, which includes a controlling end and a fastening end. The controlling end can be extended out one side the guided sliding seat, and the fastening end can be extended to the zigzag positioning groove of the sliding end. There is a resilience component placed on the corresponding location of the positioning component. The new adjustment structure of the chair backrest can be simple, have high stability, and more practicality.

Abstract: A body shaping machine has an action mechanism and a massaging belt which is fastened at two ends to two action members of the action mechanism. The action mechanism includes two deceleration devices and two displacement devices. The deceleration devices each have an output shaft, and a crank mounted on the output shaft. The two cranks of the two deceleration devices are mounted in reverse. The rotary motions of the two cranks are changed into the reciprocating linear motions by the two displacement devices, thereby enabling the two action members to bring about linear displacement motions opposite in direction.