We have had plenty of threads on leg length differences , but many things really bug me about the concepts. For eg, the concept of foot pronation as a compensation for a structural LLD has been debunked, but what about this: If someone has a structural LLD and they are standing with feet side by side, the body can probably detect the difference and compensate for it. BUT, when running there is only ever a single limb support phase and there is no phase in which both legs are in contact with the ground (let alone side-by-side).
More here:
Is a leg length difference in runners really a problem?
