I once came across this info...can't remember the link sorry:
Footsee, the newest craze with the playground set!
The toy consists of a plastic ankle ring to which is attached a30-in. string with a bell-shaped weight at the other end. The object is to twirl the string with one foot and hop with the other; well-coordinated youngsters can now twirl three Footsees at once—one on each leg and one on anarm. In the first three months on the U.S. market, about 4,000,000 of the $1.29 toys were sold. The reason cannot be novelty: a similar toy enjoyed brief popularity four years ago. Robert Asch, president of Twinpak Ltd. of Montreal, whichmakes the Footsee, is sure the game is far older; he got the idea while watching Arab children in Jerusalem playing with like contraptions.