According to this article by Owen Anderson published in Peak Performance online, wider hips cause women to land more on the outside of their soles when compared to men.
For this reason, Ray Frederickson, who has a PhD in Biomechanics says , "Women's shoes should have more support on the outside edges of the midsoles, because the outside is where the first impact with the ground takes place."
Women with narrow heels may also have a problem finding a good fitting shoe that does not slip.
Ned Frederick, PhD, another running shoe expert, thinks women need a more flexible shoe because they typically weigh less than men and therefore have more trouble flexing the shoe.
(c) Dave Elger 2007 All rights reserved