My daughter inherited her dad's flat feet.  If you don't address pronation, you can develop knee and hip problems as your feet turn in and put extra strain on you knees.  She loves the shoes (she's 14) and they help her arches and are quite stylish.  They are expensive, but if you're persistant in checking sites, you can find them on sale.  I recommend Orthaheel shoes for pronation.  You can find many shoes for foot problems at footsmart dot com.  In fact I went there first looking for sandals for my daughter this year, because her last pair (Orthaheel Lori white)&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Orthaheel-Women-s-Lori-Thong-Sandals/dp/B004N5AGG6/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Orthaheel Women's Lori Thong Sandals</a>&nbsp;was unavailable in her size at FootSmart.  And we were looking for a second pair.  So I came to Amazon hoping I'd find something that would arrive quickly (we were leaving on vacation soon.  I found these and she LOVES them.