Moon shoes were shoes for children fitted with trampoline-like springs. They were billed as "mini-trampolines for your feet". They were part of a merchandising effort by Nickelodeon

Nickelodeon (TV channel)

Nickelodeon, often simply called Nick and originally named Pinwheel, is an American children's channel owned by MTV Networks, a subsidiary of Viacom International. The channel is primarily aimed at children ages 7–17, with the exception of their weekday morning program block aimed at preschoolers...

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The original moon shoe was introduced in the 1970s and were metal in construction. They were made to fit over the wearer's regular shoes much in the same way as clamp on roller skates

Quad skates

The four-wheeled turning roller skate, or quad skate, with four wheels set in two side-by-side pairs, was first designed in 1863 in New York City by James Leonard Plimpton in an attempt to improve upon previous designs. The skate contained a pivoting action using a rubber cushion, and this allowed...

. The Nickelodeon product featured closed sides, plastic construction and bungee style springs which can be considered a safety improvement.

Another spring shoe type were sold in the early 1960s under the name "Satellite Jumping Shoes".

Kangoo Jumps

Kangoo Jumps

Kangoo Jumps are a type of spring-loaded footwear.Prototypes for springed boots were developed in the 20th century in Eastern Europe. The original purpose for the invention was as a recreation device for athletes recovering from leg injuries...

are a later spring shoe type, introduced by another manufacturer.