A different kind of heel blister
Edge blisters can occur around the heel’s rim. They’re caused by an irritation to the skin where the insole or orthotic meets the side of the shoe. As the blister fills with more fluid, weightbearing pressure pushes the blister fluid upwards. It can trick you into thinking the blister is caused by something higher up the side of the heel.
Prevention of heel edge blisters is all about two things:
Reducing pressure from the heel cup of the insole or orthotic
Reducing friction levels at that junction
1. Eliminate excess pressure from the heel cup
Insole: Some insoles are more cupped around the heel than others. These contours are most likely to cause edge blisters. Aside from that, your insole’s contoured heel cup may be creased, buckled, folded or protrude in some way. You need to flatten it out or position it so doesn't cause an area of localise higher pressure to your foot. Replace it with a new one if you need to.
Orthotic: If your orthotic has slipped forward, you’ll be standing on the heel cup, with blisters (or at least callouses) a certainty. Apply some double sided tape under the orthotic and fix it so it’s sitting correctly at the back of your shoe. This may not work if your orthotic has made an impression into the shoe - you might not be able to fix it all the way back and make it stay there. But it's worth a shot. Another cause of blisters is a thick or misshapen heel cup. Your podiatrist will be able to adjust this by either heat moulding or grinding it (pictured below).
2. Making a low-friction junction
With the heel cup of your insole or orthotic sorted out, if you’re still getting edge blisters, you’ll need to manage friction with ENGO Patches. This will create a low-friction junction between the shoe and the heel cup. Cover each surface with a separate large oval patch using the Two Patch Technique: one patch goes on the shoe, the other on the insole or orthotic (pictured below).
To get the Two Patch Technique right for the heel, you need to make sure of two things:
The top rim of the heel cup is covered with the patch (so make sure this is where the widest part of the patch is); and
There are no creases that will irritate the skin. Creases on the outside of the heel cup are fine and in fact are usually necessary on curved and contoured heel cups.
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".