A waist-and-abdomen-kneading and -swinging or waist-and-abdomen-kneading and -swinging plus back-massaging fitness apparatus, comprising: an outer frame part (10), a set of back massager (20) arranged within the outer frame part (10), a waist-kneading and -swinging belt part (30) arranged at a position within and towards the lower portion of the outer frame part (10), an annular guiding gear (11) and multiple electrically-conductive strips (13) arranged at the bottom side of the outer frame part (10), and a belt body (36) having two ends thereof penetrating a face cover (14) of the outer frame part (10). The back massager (20) comprises two kneading heads (25 and 26) used for kneading massage, and has a motor (21) to drive three gear sets respectively into transmission, or is meshed with the annular guiding gear (11) for transmission, thus driving the back massager (20) to move up and down for back-kneading massage. The waist-kneading and -swinging belt part (30) comprises a rotary shaft that is transmitted by a gear set driven by a motor (31). Two eccentric wheels (34) respectively are fixed at the two ends of the rotary shaft. Two belt body retainers (35) respectively are pivotally arranged on the eccentric shafts of the two eccentric wheels (34). Therefore, when the motor is activated while the belt body is strapped around the waist and abdomen, the swinging of the two eccentric wheels (34) and the eccentric pulling forces thereof allow for the generation of a waist-and-abdomen-kneading and -swinging action.Cet appareil de maintien en forme de type massage par pétrissage de la ceinture ou du dos et de la ceinture comprend : une partie cadre externe (10), un dispositif de massage (20) du dos logé dans ladite partie cadre externe, une partie bande de pétrissage (30) en position inférieure logée dans ladite partie cadre externe (10), un guide-dents (11) annulaire disposé sur la partie inférieure de la partie cadre externe (10) et une pluralité de tubes conducteurs (
