#478 Can a blister on the big toe cause peroneal tendinitis? - DOC

#478 Can a blister on the big toe cause peroneal tendinitis?

Can a blister on the big toe caused peroneal tendonitis? Well, that’s what we’re talking about today on the Doc On The Run podcast.


Now, I just got a great question from one of the runners in our weekly, Monday, Wednesday, Friday doctors office hours for recovering runners and this is where I actually meet with runners all month long on a Monday, Wednesday, Friday basis, as runners are actually getting back to running and they’re trying to make sure they don’t make an injury worse.

The question was actually a really good one. This is somebody who said he went rock climbing over the weekend and he got a huge blister on his big toe from his climbing shoes. And so he didn’t really complain that much about the blister, in fact, he’d even been running. But then he said he was getting peroneal tendonitis. He was having this pain on the outside of the ankle where the peroneal tendons go down around the back of the fibula bone.

He wanted to know if it was somehow related to the blister on the big toe. And he didn’t really think so, because it’s the completely opposite side of the foot. But the fact is that actually can happen, and it’s because they’re on the opposite side of the foot.

So obviously your big toe is here. The peroneal tendons are over here. So the peroneal tendons curve down around, behind the fibula and the peroneus brevis tendon attaches to this little bump on the outside of the fifth metatarsal bone, and it helps to hold your foot stable, and it prevents you from rolling your ankle. Well, because it prevents you from rolling your ankle, it is the thing that you will fire oftentimes to stop you from actually losing your balance. And what happens though, is that when you have some injury around your big toe or on the opposite side of the foot, you compensate.

So you basically twist your foot to keep the big toe off of the ground. And as you pull the inside of your foot, the arch, the medial side of your foot, as you pull the arch up and you move the big toe away from the ground, it actually stretches the peroneal tendons where they curve around the outside of the ankle and under the bottom of your foot, around the fifth metatarsal and the cuboid bone.

When that happens, it can actually cause peroneal tendonitis. And peroneal tendonitis often scares runners, because when you look it up, there’s a lot of discussion about surgical repair of peroneal tendons in athletes and how it doesn’t heal if you don’t have surgery. So many times I get questions from runners about the peroneal tendons, like the peroneus brevis tendon, where runners have a little bit of irritation. They’re a little bit concerned about it, and they really start to get worried once they look it up, because they start to believe they might need surgery to repair it.

Now, that is not going to be the case with this runner. Some really simple things we talked about during our call on webcam just to reassure him that he could get it back under control really quickly and then get back to running. But trying to compensate to keep pressure off that blister as it’s healing is what’s really causing the problem. So the blister in itself is not going to be a problem. And in the end, I don’t think the peroneal tendonitis will be a problem either. But that’s how a blister on the big toe can actually cause peroneal tendonitis in a runner.