At least once a week I treat a runner with painful calluses under one or both big toes. This type of callus is known as a pinch callus and typically goes unnoticed until it gets so thick a blister forms underneath it, or causes pain due to lack of cushioning from the running shoe.
Removing the pinch callus alleviates the pain, however understanding the cause is key to preventing a recurrence.
Today, a runner came in having a pinch callus and didn’t realize the cause was his unsupportive running shoes. When the foot collapses, or pronates, during running, push-off of the big toe occurs on the side of the toe as opposed to the bottom. This in turn creates friction, and when there’s skin friction, there’s callus. Using our scientific gait analysis video software, you can see how this runner’s right foot pronates significantly. This is made worse by wearing the wrong type of running shoe for his alignment.
If you or someone you know suffers from pinch callus, don’t wait until it causes pain. Make an appointment with your Sports Medicine Podiatrist to have it shaved down. Also ask them to check your gait for excessive pronation, which may be the underlying cause.
Sometimes a more supportive shoe is all that’s needed to reduce a pinch callus buildup and sometimes custom orthotics will be necessary to reduce excessive pronation. Either way, pinch callus is not protective and should not be ignored.
Life happens. Don’t wait.
Dr. Jenny Sanders Shoe Blog 
Dear Dr Sanders (Jennie), thanks for another wonderful post that will help our patients. Dr Rich Blake (friend and colleague)
Thanks Rich. I hope everyone’s heading to your blog – drblakeshealingsole.com for equally valuable information as well!
I have a question. I have a pinch callus on my left great toe but I walk toed in and supinate with that foot. What would cause a pinch callus if one does not pronate? Do I spin on that toe causing the callus?
Good question Shelley. If your rearfoot excessively supinates at heel strike, your forefoot will excessively pronate in response. If it didn’t, you would have to run on the entire outside of of your foot (rearfoot and forefoot), which would be inefficient and unsustainable. This compensatory pronation, coupled with structural in-toing (metatarsus adductus) will further overload the side of the big toe joint, producing excessive motion and friction. Although this will produce a different running gait than what you see on the video, pinch callus will still develop. Hope this helps.
-Dr. Shoe
Thank you, very helpful. It is a challenge to get my left foot to land straighter. I have a forefoot valgus on the Left. My Right foot has a short first met and is more neutral in the forefoot but I toe in bilaterally. Needless to say, I am always battling, trying to get my gait to feel more even.