You know those extra two shoelace holes that sit off to the side on your running shoes, just far enough that no one ever seems to use them? Did you think they were just a decoration? Turns out they actually do serve a purpose. Mystery solved!

Those two holes can create a "lace lock" that reduces blisters on your heels and toes by more firmly securing your foot inside the sneaker. That should come as pleasant news for anyone who's felt their foot moving around in their shoe, which is what leads to those irritating blisters. And we thought it was just because we needed better socks. But as always, the internet has come to the rescue -- in this case, via the helpful folks over at Illumiseen.

So what exactly does a lace lock (or "heel lock") do?

[The lace lock] creates extra friction between the laces at your ankle. This keeps the ankle and heel area nice and tight, without having to tighten your whole shoe. It also helps to prevent black toenails by keeping your heel and your toes from smashing into the front of your shoe.

Seems simple enough. We'll give it a shot. If it doesn't work out, we can always just go back to buying ever more socks, until we find the perfect pair.