More on children's foot maturation.

source article:

Watch what you put on your kids feet! encourage them to go barefoot early or use a minimal support type shoe (like Robeez or similar with a soft leather sole)
“Shoes affect the gait of children. With shoes, children walk faster by taking longer steps with greater ankle and knee motion and increased tibialis anterior activity. Shoes reduce foot motion and increase the support phases of the gait cycle. During running, shoes reduce swing phase leg speed, attenuate some shock and encourage a rearfoot strike pattern”.

Effect of childrens shoes on gait: a systematic review and meta analysis J Foot Ankle Res. 2011 Jan 18;4:3.