Very frequently one part of your body compensates for a failure in another part of your body. As a result the bit that hurts can be surprisingly far from and t

Very frequently one part of your body compensates for a failure in another part of your body. As a result the bit that hurts can be surprisingly far from and the part where the underlying problem exists. That said, the principle is simpler to apply in theory than practice. There really are people who understand the human body well enough to debug it. Their results demonstrate that they aren't making it up, but I have no idea how they actually do it.