File:1892 wobble board precursor by William Madsen.png

These are the five patent drawings for a physical-fitness exercise device.

The inventor was William Madsen of Chicago, Illinois.

The 1892 U.S. patent for this device was applied for also in 1892. Its patent number is 478,166.

This device (rather than one invented by Bernard L. Coplin, whose 1957 U.S patent was applied for in 1954) would be the first wobble board known to be patented if it could be stood on without the user holding on to some stable external support, but there are three indications in the patent that it couldn't be:

The patent refers to "suitable devices adapted to be grasped by the user."

In the patent's drawing, the size of the base puts the board about two and a half feet above the ground, a height unlikely for an inventor to recommend balancing at (unless the intended user is an acrobat or, at least, a gymnast, which the patent doesn't indicate is the case).

The patent says: "It will be seen that in the several modified forms of my invention above illustrated a rest is provided whereon the weight of the user of the apparatus will be exerted– that is to say, in the construction shown in Fig. 1 the saddle constitutes a rest to sustain the entire body of the user, and in Figs. 3 and 4 the foot-plates constitute rests for sustaining the user's feet." This description of the foot-plates's purpose doesn't say, as the description of the saddle's purpose does, that they are meant to "sustain the entire body of the user." Although it might be supposed that "sustaining the user's feet" implies sustaining a user's entire weight, this omission when considered together with the two previous indications seems not to imply this.