The significance of painful “niggles” during exercise

It’s not an injury… yet.

You get a nasty knee twinge while you’re being sporty and physically intense. It’s nothing terrible, just a niggle really, not enough to stop you… but maybe you should stop?

What do you do? Get off the field or the track? Turn around and hike for the trailhead? What if that twinge is a meaningful warning? What if you could know that the twinge means that your risk of an injury just tripled?

No one knows that, unfortunately.

Despite athletes being studied as much as lab mice, this warning sign — which would have immense value to the elite sports industry, if confirmed — has barely been touched by researchers.

But it has been touched now, by Whalan et al. They produced some data showing that minor physical complaints — “niggles” — are probably clear warning signs of more serious athletic injuries. (They even put “niggles” in their title, for extra charm points.) They surveyed 218 soccer players for a season. In any given week, about a quarter of them had a complaint that did not prevent their participation, just something bugging them. And those complaints were linked to at least triple the risk of a more serious injury over the next week. 😲

(Aside: I am not sure I have gone a day without a niggle — let alone a week — in about five years now. And if I stopped for every niggle, I’d never do anything active at all!)

“Do Niggles Matter? - Increased injury risk following physical complaints in football (soccer)”
Whalan et al. Science and Medicine in Football. Volume 4, Number 3, 216–224. 2020.

What about injury risk on the same day?

It would be great to study this in more detail, especially the link between minor complaints that crop up during an event, and the risk of an injury before that event is over. That is, does a fresh “niggle,” or a flare-up of an existing one, increase the risk of imminent injury?

That’s a much tougher experiment. You’d have to define “warning sign” quite carefully, and then get a lot of athletes to agree to either heed them or ignore them in competition! Tough data to get.

But my hypothesis — which I’d love to be able to test — is that many injuries are in fact preceded by clear warning signs just minutes before, injuries that could be prevented if we immediately backed off.

For whatever it’s worth — not much — I did a very unscientific Twitter poll to see what people think of the risk posed by niggles. Based on their own experiences with injuries, about half of respondents reckon a niggle probably suggests “moderately greater” short-term risk.