Once you have selected your running shoes, over time they can point towards problems with your feet. The nature of the wear and tear that occurs to your shoes can become a useful diagnostic tool as to how you run on your feet.

While it is usual to see shoe wear on the outer part of the heel, deterioration of the inner heel could indicate over-pronation, which occurs when a runner pushes off almost entirely from the big toe and second toe, so the foot’s impact doesn’t spread evenly and the ankle has difficulty stabilizing the rest of the body. Over-pronation, common among people with flat feet, can result in knee and shin pain and other running injuries. Proper shoes can improve symptoms quickly and prevent them from recurring.

Excessive shoe wear on the outer sole of the forefoot and heel area can be a result of a rarer condition called over-supination, which happens when there is an insufficient inward roll in the foot’s motion as it strikes the ground. Over-supination may also call for a change in footwear, plus muscle stretching and strengthening exercises.