Have you ever done a measurement of the arch of your foot the one in which you dip your foot in water and make an imprint on a piece of paper to determine your arch, or plantar, shape? U.S. Army researchers looked at whether this more meticulous selection technique had any influence on injury in 1,500 recruits, compared to another 1,500 who were given stability shoes that weren't chosen based on the particular plantar contour of their feet. They concluded in the May 2009 issue of The Journal of Strength and Conditioning Research that choosing a shoe based on a plantar outline did not offer additional protection against injury. What does keep injuries away? Replacing old shoes when they no longer provide support, which can occur at about 400 miles of use.