Underneath. And on the outer corner of the toe.
What causes big toe blisters?
Blisters under the big toe are more than likely a consequence of your foot's structure or biomechanics. Here are some potential causes:
- You walk with your feet turned out and roll off the side of the toe rather than toeing-off straight through the toe.
- Your big toe is angled towards the others (often the result of a bunion) and the same thing happens.
- You're wearing shoes that are too narrow at the toes, so a part of your big toe is "hanging over the edge" of the shoe.
- Your big toe knuckle (1st MPJ) is stiff in the upwards direction causing higher weightbearing forces under the big toe.
- Your big toe knuckle has plenty of upwards bend when you're off your feet. But when you're on your feet, this range of motion becomes unavailable for biomechanical reasons (more on this below).
A common biomechanical cause of big toe blisters
The Windlass Mechanism
The windlass mechanism is an important biomechanical function in the foot that promotes efficient gait. When this is not working efficiently, one consequence is lower forces under the big toe knuckle and high forces under the big toe.
Take a look at the pressure map above. This person had what we call a "functional hallux limitus" (FnHL). A FnHL is caused by an inefficient windlass mechanism. That means she had plenty of upwards bend at the big toe knuckle. But when she walked, this range of motion was not available. And so an excessive amount of pressure was borne by the big toe. A more normal pressure map would see red under the knuckle, not under the big toe.
Don't forget friction
The friction properties of all the materials within your shoe are high. I'm talking about:
- Your clammy skin
- Your socks
- The lining of your shoes
- The innersole
- The cover on your orthotic
It's important that these materials are high friction. Because your foot needs traction within your shoe. You don't want your feet sliding around too much in there! Thankfully, most people get away with these high friction levels most of the time. But for some of us, this high friction when combined with high pressure, produces an amount of skin shear that causes blisters.
Preventing big toe blisters
Let's home in on what I believe are the two most important preventative strategies for big toe blisters.
1) Dealing with the biomechanics
The best way to deal with high pressure under the big toe (including edge blisters) is to see a podiatrist. They will figure out if there is a reason that can be fixed by changing your biomechanics. The blisters mentioned earlier (pressure map) were addressed successfully with orthotics. Not just any old orthotics though! Orthotics with specific design features that are known to facilitate the windlass mechanism. So load is reduced under the big toe. Podiatrists have many tools and therapies at their disposal that can improve this important biomechanical function. If you're getting recurring big toe blisters, I recommend you get your feet checked.
And they can help guide you with shoe fit and selection. If it's more of a structural reason, it’s not quite so easy to significantly reduce pressure. In these situations, managing friction in this specific location is paramount.
2) Cutting friction levels with ENGO Blister Prevention Patches
If changing foot function is insufficient, you’ll need to rely on reducing friction levels. If the blistering is under the toe only, one patch under the toe is all that’s needed. The patch shown on the insole is a large oval patch, from the ENGO 4-Pack. If you’re dealing with more of an edge blister (watch the video to figure that out), use the Two-Patch Technique. In this instance, you'll need two of these oval patches per shoe.
These oval-shaped ENGO Patches provide versatility for any blister situation. The shape makes them easy to apply to any area of the shoe and the size provides perfect coverage for most blisters. Most commonly used for blisters under the ball of the foot, top of the toes and edge blisters.
- 4 x Large Oval Patches (4.4cm x 7cm) in each pack
A Podiatrist and a couple of ENGO Patches are your best chance of stopping even the worst cases of blisters under the big toe.
Written by Rebecca Rushton
Rebecca is an Australian podiatrist with over 20 years experience. She has spent a lifetime dealing with her own blister prone feet in her sporting and everyday life. Rebecca specialises in helping athletes and sports medicine professionals figure out how to manage foot blisters with ease. And for kicks, she enjoys providing blister care at multiday ultramarathon events.
Rebecca is the founder of Blister Prevention and author of "The Blister Prone Athlete's Guide To Preventing Foot Blisters".