I am frequently asked about passing shoes on to siblings or friends and whether this is ok, the simple answer is no ... these are some of the reasons why.
I completely understand the temptation ... children's shoes are expensive and they can grow out of them so quickly! However, while the shoes may still look good, or at least passable, on the outside, it is the internal wear that causes the greatest problem.
Shoes made of natural materials, such as leather and cotton (generally the best choices for footwear), will mould to the shape of the wearer. After just a few wears you will start to see an imprint of the foot forming on the insole. If another child then wears the shoes their foot will try to adapt to this imprint, this can affect the way they place their foot and in turn how they position their whole body when on the move.
The sole of the shoe may also have worn unevenly, depending on the previous wearer's walking pattern, this again can potentially throw the body out of alignment.
Children's feet sweat twice as much as an adult's, a leather shoe will draw this moisture away from the foot and help to regulate it's temperature. All good so far, however, over time this process will start to degrade the leather from the inside. I don't know about you but the thought of putting my foot inside someone else's sweaty shoe is not appealing!
Most importantly, no two pairs of feet are the same, even siblings can have vastly different shape feet. When fitting a pair of shoes we check length, width, height of the instep, fit at the heel and around the ankle and consider other factors that might influence the choice of shoes. The chances of all these factors being the same for both children are low.
The bones of the feet remain soft and vulnerable to damage until they stop growing during the teenage years, until this time persistent pressure on part of the foot, particularly the toes, can cause a permanent deformity. A pair of shoes specifically chosen to suit the shape of their feet and stage of development really is the best way to ensure their future foot health.
Finally, having said all of this, there are instances where having a pair of hand-me-down shoes is better than having no shoes at all. Charities such as Sal's Shoes, Little Village and ShoeAid, collect preloved shoes and ensure they find their way to some new little feet, which will be very happy for the protection they provide.