Maybe these 1927 midsized wheel devices from France (LOOK UP THREAD) caused some to get sprained ankles
So maybe that's why they never were commercially made, after 1927?
https://razor.com/age/kids/ Looks like the company RAZOR made the flipping kids scooter, safer
Maybe adding a brake and a helmet fixed the problem of injuries
Maybe not having one aged 4 to 10 use the razor scooter was the solution