The present invention refers to a shapewear device for the adjustment of an electrode belt around the body of a human or animal patient. The device of the present invention comprises: one tensioner body (3)； at least one first arm (2A) and one second arm (2B)； both arms (2A, 2B) stretch out from the tensioner body (3) in opposite directions, each arm (2A, 2B) has a free end (7A, 7B) comprising at least one mean of fastening (4) to an electrode belt.
