Q&A: Can “compensation” for an old injury cause a new pain?

This is a very common kind of question about back pain and other common mystery pains:

“Can “compensation” for an old injury cause a new pain? Was my new painful problem caused by the stress of compensating for that old hip injury? Was I so weak/unstable/unbalanced that other anatomy was taking the load and eventually got into trouble?”

Mostly no. There are exceptions to every rule, but the rule here is clear: “compensation” for old injuries as a major mechanism for new injuries is probably rare.

And we are talking about “new” injuries here: that is, relatively out-of-the-blue problems that need an explanation. Compensation for an old injury gets proposed in the absence of an obvious explanation. Of course severe injuries can relentlessly cause obvious strain from trying to adapt to them. But people don’t ask about those. There’s no need. Obvious is obvious!

What people are asking about is if there could possibly have been a subtle-yet-corrosive force, something that they were barely even aware of, leading eventually to a surprising failure.

This is the “slow loading” hypothesis. To be true, it means that old injuries have to result in adaptations just awkward and stressful enough to cause wear and tear to eventually lead to tissue degeneration and new injuries … but not enough for the process to be obvious along the way (or the question wouldn’t even need to be asked).

And that’s generally implausible. A problem that’s like mild arthritis, or something like it, is unlikely to be more much painful than such problems normally are … and they aren’t usually very painful (it takes quite a bit of severity and other physiological factors).

I also have serious doubts that even mild chronic overload would occur without rather glaring dysfunctional posture/movement, and there is good evidence that such forces are clinically trivial in general. We’re mostly just not that fragile.

In other words, non-obvious compensation for old injuries is also probably non-serious, and unlikely to drive future injuries. If there are exceptions, they would live in the gray zone between obvious and non-obvious compensation — and I don’t think it’s a huge gray zone. It’s not that compensatory injuries don’t exist at all, it’s just that the concept is quite badly abused and overused.