This is a disappointing article to write as I been going on about it for more than 15 yrs, have written about it before in several other places and so have a lot of other people, but the myth just won’t go away. The myth is that when there is a leg length difference, the foot (or more specifically the subtalar joint) will pronate more on the longer leg side to compensate for the difference in leg length (and by implication, allegedly increase the risk for overuse injury due to that overpronation ). The myth did not start with the good work of Bill Sanner , but this work was used to reinforce the myth.
Read the article:
Foot Pronation and Leg Length Differences