As I take my child to school I often notice how inappropriate some kids' footwear is for riding bikes and scooters. I see many kids on both with only flip flops, or open toed sandals, or shoes without a back. I have often seen children come off bikes or scooters (I saw this twice today). It really seems very dangerous having bad footwear as in any situation where the rider needs to use their feet to protect them in a sudden movement, the toes are the first thing to get hurt. Yes, wear helmets, but remember that grazed toes and feet are just as likely in a tumble.
This goes for adults too. Correct foortwear should be modeled to our children and then it will be easier for them to see what is the correct attire.