This article in ‘The Journal of Foot and Ankle Research’ looks at the medical evidence of how shoes affect the way children learn to walk and run. Part of the conclusion is below and the link to the article follows:
‘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. The long-term effect of these changes on growth and development are
currently unknown.
Please see this link for the full article