"It is impossible to say exactly when the Finnish hobbyhorse craze began, because it spread for years under the radar before adults became aware of it.
In 2012, a filmmaker, Selma Vilhunen, stumbled across internet discussion boards used by hobbyhorse enthusiasts and was enraptured.
Teenage girls had invented a form of hobbyhorse dressage, in which the rider’s lower body pranced and galloped like a horse, while her upper body remained erect and motionless like a rider. This evolved into an elaborate network of coaches and students and competitions, but it was discussed only online, for the most part.
“It was like a secret society,” Ms. Vilhunen said."
https://www.nytimes.com/2019/04/21/world/europe/finland-hobbyhorse-girls.html
In 2012, a filmmaker, Selma Vilhunen, stumbled across internet discussion boards used by hobbyhorse enthusiasts and was enraptured.
Teenage girls had invented a form of hobbyhorse dressage, in which the rider’s lower body pranced and galloped like a horse, while her upper body remained erect and motionless like a rider. This evolved into an elaborate network of coaches and students and competitions, but it was discussed only online, for the most part.
“It was like a secret society,” Ms. Vilhunen said."
https://www.nytimes.com/2019/04/21/world/europe/finland-hobbyhorse-girls.html