#609 How can a 2nd metatarsal stress fracture cause a 5th metatarsal stress reaction? - DOC

#609 How can a 2nd metatarsal stress fracture cause a 5th metatarsal stress reaction?

Today on the Doc on the Run podcast we’re talking about how a second metatarsal stress fracture might cause a fifth metatarsal stress reaction.



I was just on a call with somebody, on a webcam call, who had had a second metatarsal stress reaction, which is basically like a mild stress fracture and that had actually been getting better but then when she went for her first run, she had a different pain, and that pain was on the outside of the foot.

So let’s talk about how that happens. When we look at your foot and we’re talking about the metatarsal bones, you’ve got the first metatarsal here, you’ve got the second metatarsal here, third metatarsal, fourth metatarsal, and the fifth metatarsal.

What we’re talking about in this case is this is someone who had had a stress reaction where this bone’s inflamed, the second metatarsal. And then when she went for her first run after she was getting better, she started to have pain over here. Well, how can that happen? Is it contagious? Did it spread from one to another? No. But we’re going to talk about the way that does happen.

If we look at your foot, to make it simple, in cross section where this is your leg coming down and this is your foot, and we’re looking in cross section say through here. You have your first metatarsal bone, your second, your third, your fourth, and the fifth metatarsal bones and so let’s say you have a stress reaction here. Well, your brain knows that this thing is irritated and aggravated and when you’re walking on it, there’s pressure under it. So the way to get the pressure off of that bone is to tilt your foot.

If you then tilt your foot in this direction so that the ground, instead of being right under your foot is actually angled and you’re supinating your foot to take the stress off of there and you get that second metatarsal way up in the air so that there’s no pressure on it, because you’re holding it up away from the ground. Well, what does that do? It puts a ton of pressure on the outside of the foot.

This is very, very, very common. So now you have basically metatarsal overload on the fifth metatarsal. So right here, that little fifth metatarsal bone. You’re tilting your foot, you’re standing on the side of the foot, you’re running on it and your brain, knowing that you’ve got inflammation in the second metatarsal bone, is moving it away from the ground.

Well, how do you know that? Well, one of the ways you can tell when you’re running is if you’re doing that, a lot of times the simplest way to do it is to tilt your foot inward and so if you look down at your feet, instead of your feet being perfectly straight, one of them might be slightly tilted inward. And that would be a sign that you’re supinating and compensating without even thinking about it. Unconsciously, tilting the injured second metatarsal up away from the ground.

But then you can start to get another problem over here in the fifth metatarsal. So that’s the way that can happen. It’s not because it’s contagious, it’s not because the stress fracture spread, it’s because your brain is trying to protect you when you’re running and take that more significant injury and keep the pressure off of it and if you’re doing that, you need to try to address that because you do not want to develop a fifth metatarsal stress fracture. That’s actually, in many ways, worse than a second metatarsal stress fracture.

If you found this useful, please like it and share, subscribe and then, if you haven’t seen it yet, you might enjoy the Metatarsal Stress Fracture Masterclass that I put together for you. You can get it by going to docontherun.com/StressFractureMasterclass/, this is a deep dive where I go into all this stuff you really need to think about if you’re a runner with a metatarsal stress fracture. So go check it out, sign up, it’s free, and I’ll see you in the training.