<p>momoftwins: Good running shoes that match your daughters biomechanics are essential for marathon running. Running shoes that fit properly and match your daughters foot strike should not need to be broken in. Ideally she should have two pairs and alternate them. As soon as they start to break down they should be replaced.</p>
<p>This link may be useful: <a href="http://www.geocities.com/madeads/shins.html%5B/url%5D">http://www.geocities.com/madeads/shins.html</a> </p>
<p>Good luck to your daughter - marathon running is a great sport!</p>