"If you run for more than five minutes at any time, you might need a pair of running shoes." Advises Stephen Pribut, a US sports expert. Running shoes are highly technical footwear. The provide stability  while bearing up to three times the wearer's body weight. But it's not easy to find the right pair. Finding the right running shoes is something of an art, or a science and a feel.       The science part begins with the shape of the arch  of your foot, which anyone can find out at home with this quick experiment: Put your foot in water and place it on a piece of brown paper. If you see a "C" shape on the paper when you remove your foot, you have a rare high arch. If the shape looks more like a rectangle, that means you have flat feet. See something in between? That's a normal arch.            Conveniently for shoppers, shoe companies nowadays divide their shoes in three categories: neutral ( for high arches), stability ( for normal or low arches) and motion control (for flat arches). So you'll know which type suits you.       At this point, most people would just grab an appealing shoe and try it on, But professionals would do a few quality-control tests. First, you bend the shoe toe to heel to see where it bends. If it's not at the forefoot---where the foot actually be bends, be afraid. Then you grip both ends and twist in opposite directions. If you can twist it like a tower, it means there's zero support. Finally, you squeeze  he heel in both directions. A stable heel won't  _ .       Now you need to check the mold  that shapes the inside of the shoe: whether its wide or narrow in the mid-foot, how it sits on the heel and how roomy the toe box is.       It's wise to make the shoe purchase in the late afternoon, to allow for any swelling  that your feet do throughout the day. Toes also decide sizing choices. The rule is that you need a finger's width from your longest toe (whether that's your big one or not) to the end of the shoe. If the arch of your foot look like a "C" shape, you have   _  .
a normal arch a high arch a flat arch a low arch