#879 Can peroneal nerve tendinitis cause 5th metatarsal pain? - DOC

#879 Can peroneal nerve tendinitis cause 5th metatarsal pain?

Can peroneal nerve tendinitis cause fifth metatarsal pain? Well, that is what we’re talking about today on the Doc On The Run Podcast.



Today’s episode comes from a comment or a question as a comment anyway, on one of the YouTube videos I have made on peroneal tendinitis, and this runner asked the question, “Can peroneal nerve tendinitis cause fifth metatarsal to be tender to the touch and when walking, I am not sure if I have a stress fracture.”

Okay, well, I am confused, and I will explain why because I am not really sure what is going on with this runner, but I am going to try to explain and answer the question as best I can. So, let me draw a couple pictures here. This is the outside of the foot. So, let’s imagine your little toes here, big toes over here and it is a terrible drawing of a foot but anyway, you get the idea. So, what do we have in there? Well, we have the heel bone, talus sits on top of the heel bone, tibia sits on top of there, the fibula bone is on the outside, you have the navicular and the cuboid, and you have cuneiforms, and the fifth metatarsal bone, and all the other metatarsal bones.

This is the fifth metatarsal, right, so we have a bone, the fifth metatarsal bone here and this person is worried about a stress fracture. So, I am assuming that the pain is in this bone or somewhere around that area. So, that is thing number one, stress fracture. Well, yes, you could have pain if you have a stress fracture. And if it is inflamed, you have swelling within the bone or in the covering of the bone over it because you have stress reaction that could hurt. So yes, you could get a problem with that.

The next question is the tendon. Okay, well, you have a tendon. The tendon, the peroneal tendons, specifically peroneus brevis tendon, peroneus brevis muscles up here, comes down behind the fibula and then attaches right here to the base of the fifth metatarsal. So, when you look at it from the top, if I can draw another picture and try to make this a little more descriptive.

Okay, here’s your foot, there’s the fifth metatarsal bone and this tendon, the peroneus brevis tendon just coming in to attach here. Since it is on the outside of the foot, that is the one that fires and pulls your foot back onto you when you start to roll your ankle. So yes, if you have insertional peroneal brevis tendinitis where it attaches to the bone right there, then that is  a separate problem called tendinitis, specifically peroneal tendinitis.

The other question here, what about the peroneal nerves? Well, it is sort of or sort of not could that be a problem because you  have a couple of different nerves here. You have one of them, the intermediate dorsal cutaneous nerve comes across here and goes like, basically right out here toward the fourth toe up there. It is part of the superficial peroneal nerve. So, I do not know where this person got the anatomy descriptors for this, but the superficial peroneal nerve really does not cause pain in the fifth metatarsal. It could theoretically cause some pain in this general area, yes, I guess it could, that would be pretty strange. It would be unusual.

If you get irritation of the sural nerve that comes down here, that is more likely to be causing pain in that area because it is closer to where the actual trouble is, where the insertion of the peroneus brevis tendon goes over the fifth metatarsal. So, it is three different things. A nerve problem, a bone problem or a tendon problem.

I guess at the base of the question is can the tendinitis issue with the peroneus brevis pulling on the muscle causes stress fracture. Yes, it causes traumatic fractures a lot where you roll your ankle so hard that instead of pulling the tendon loose, it cracks the bone right here and causes an actual avulsion fracture, meaning that you Avulsed or ripped the bone right off, that happens a lot. Very common. Less common is to get a stress fracture there from tugging on it persistently but I suppose if you’re running in unstable shoes on unstable surfaces, that you could get persistent tendinitis that does that.

The other way that it can conceivably happen is that if you have chronic tugging away of the bone, and it is chronically inflamed and irritated. You have inflammatory fluid in there, that the increased blood flow and the degradative enzymes that degrade the collagen over the periosteum and stuff, theoretically, could like keep it inflamed and then because of your sort of washing out the calcium in the bone with the chronic irritation and inflammation, where the tendon attaches to the bone, it could get weaker and develop a stress fracture from that process. So, it is possible.

Yes, you could have peroneal tendinitis, that leads to fifth metatarsal pain and even potentially the stress reaction or stress fracture in the fifth metatarsal under those circumstances. So, if you haven’t checked it out yet, if you think you have a stress fracture, you might well check out the stress fracture masterclass.

You can get it for free at https://www.docontherun.com/stressfracturemasterclass. It is where I do a deep dive into all the strategies I use with athletes who have stress fractures and want to get back to training instead of just waiting for the thing to heal.

Go check it out, https://www.docontherun.com/stressfracturemasterclass, and I will see you in the training.