Also consider elbow and knee pads. Make sure there isn't any loose clothing that could catch in the wheel or chain. Added Hoag-Apel, "The bike should fit the rider. You shouldn't buy a bike they're going to row into. Where they can straddle it and hit the ground or when they're on it - the pedal in the low position their leg is straight."
And make sure to teach them traffic rules, like how to signal for a right hand turn. "They dart out from driveways. Children don't understand traffic situations. They think because they can see the car, the car can see them," said Hoag-Apel. Common injuries include damage to the spleen or liver, broken arms and legs and even brain injury.