As shown in the illustration, there is nothing to prevent the heel of the foot from riding up slightly because of the way a boot is constructed. When the boot is new, the sole is stiff. With time, most of the slippage will disappear. If the instep is too loose, the boot will slip excessively in the heel. To remedy this, you may need a more narrow width to shorten the circumference of the throat and thus lessen the slippage without cutting down on the length of the boot.
Slight slippage is necessary to obtain a proper fit.
Justin Brands a Berkshire Hathaway company. All rights reserved.