Electric Dumbbells

Electrical stimulation of muscle tissue during exercising was the purpose of many patented devices, which began to appear in the 1880’s. The simplest of these devices were the electric dumb-bells. Unlike the galvanic spectacles covered in part 1 of this series, which continuously produced tiny currents, electric dumb-bells used induction coils connected to batteries or magnetos to produce a more substantial “shock”. Of the 10 patents for electric dumbells, 3 provided a self contained battery and induction coil within the dumb-bell. Three patents were for a self contained magneto. One of these was driven by the user’s finger, similar to a generator flashlight. The second was weight driven and activated each time the dumb-bell was inverted. The third type was driven by a clockwork contained in one end of the dumb-bell. One patent was for a dumb-bell electrode for use with a conventional electromagnetic machine. The last class of electric dumb-bells (3 patents) provided a separate battery and induction coil worn on a belt or around the neck and wired to the dumb-bell electrodes. A precursor to the electric dumb-bell was patented in 1883, by William McGinnis, of New York. It was simply a hardened steel dumb-bell which was strongly magnetized. McGinnis states in his patent “Being thus magnetized, it will, when grasped in the hand, act in the usual manner to stimulate the nerves and fibrous tissues of the hand and arm”. Three months later, McGinnis applied for the first patent for an electric dumb-bell and Indian club. The dumb-bell, made of non-conducting gutta percha, contained a bisuphate of mercury battery and an induction coil. He states in his patent, “The object of my invention is to admit of the generation and transmission of a gentle electrical current through the muscles and tissues of the body, simultaneously with their exercise, as they are brought into play by the use of appliances adapted for the purpose”. Electric dumb-bells were generally made of wood or India rubber with metal contacts where the hand would grasp it. The ends frequently had removable hemispherical caps to gain access to the internal parts. Often, only one dumb-bell of the pair contained electrical components and the other was simply an electrode, with a wire providing electrical connection to the coil.