Here's a photo. from Got Weird on Instagram. of a "Woman wearing motorized "skates" by NSU Motorcycles". This fantastic promotional shot dates to 1952. If you haven't heard of motorized skates until now, join the club.
I love how these look more like something one would wear while walking around in outer space than for skating. It looks like each skate has a controller attached to a wire that the skater holds to increase or decrease the speed.
And of course, there is no helmet involved. Looks extremely safe to me!