What exactly is a boot shank? truly positioned, the shank is a load-bearing piece of metal (or any other hard, bendy material) this is sandwiched between the insole and the outsole of your shoe. it usually sits among the ball and heel of your foot, underneath the arch. you can’t see it, but it’s there to aid you: shanks relieve anxiety through diminishing the burden on your arches, calves, and knees, and assist you hold your stability on uneven terrain. They also keep the form of the boot over time, which means that you’ll get the maximum from your investment.