As any parent knows, children's feet grow quickly. In fact, a recent study found that a majority of children (at least those ages 5 to 10 in the study group) were wearing shoes that are too small and put them at risk of developing serious foot deformities. The problem is compounded by the fact that most children outgrow their shoes before they have had a chance to wear them out.
If you need to buy new athletic shoes for your child, either because his feet have grown (check for fit every month, especially during growth spurts) or because they are worn out (again, don't be lulled into thinking that shoes aren't worn out because the soles look fine; the mid-sole, which provides the cushion, can become compressed and lose its shock-absorbing ability, before the soles shoe signs of wear), you may be considering hand-me-downs or used shoes as an alternative for brand new shoes.
If you are considering hand-me-downs or used shoes, there are two main factors to consider. First, whether the shoes are too worn to offer adequate support, and second, whether the shoes have become so adapted to the original owner's feet that they may actually have a negative affect on your child's foot structure. Compressed cushioning inside the shoe may have molded to the first person's foot, causing problems for the new owner, including arch pain from not enough arch support, and blisters.
So, the bottom line is, hand-me-downs or used athletic shoes may be okay in some circumstances, but be careful you aren't being penny wise and pound foolish when it comes to the long-term health of your child's feet.