Cracks in the skin at the back of the heel are unsightly and can be painful. They are reasonably common, especially in those people who are susceptible to them. These kinds of splits in the skin about the heel occur when the skin is thicker and dry. As the fat bad under the heel bulges out sideways when walking puts pressure on the skin that it may not take, so the skin just tears or cracks. The wearing of open back sandals also contributes to this condition of cracked heels. Various medical conditions might also contribute to the dryness of the skin and a number of different biomechanical issues contribute to the thickening of the skin.
When a split occurs, it does have to be treated as it can act as a entrance for an infection to get in. First of all, an antiseptic should be used to prevent that if the crack is open. It is next necessary to take off the thick callus around the peripheray of the heel. This can be done by a competent podiatrist if you have access to podiatry. If not, you'll need to use something like a foot file, pumice stone or emery board and get to work on reducing the callus. This can take a lot of effort. When that callused skin is taken care of, then it's important to use lotions and emollients to help make the skin elastic and adaptable so it doesn't have the tendency to crack. Urea based creams are usually much better for that. Once this original problem is taken care of, then preventative measures have to be put in place to continue with or else the cracked heels will in all probability happen again. Regular use of a foot file or similar is advised to keep the thick skin down and frequent use of a urea based lotion is essential to help make the skin resilient to cracking and stop the dryness. Avoiding open back shoes is also recommended to prevent cracked heels.