Device for the relative movement of bones, in particular for the treatment of scoliosis in humans, with a first shaft element (1), a second shaft element (2), which is connected movably to the first shaft element (1), and an electric motor, which is connected to the first shaft element (1), wherein an output shaft of the electric motor is operatively connected to the second shaft element (2) in order to permit a movement of the shaft elements (1, 2) relative to each other, wherein the electric motor (6) is arranged lengthways adjacent to at least one of the shaft elements (1, 2).