Extreme Shoe Modifications

If you suffer from blisters, sometimes they can prevent you from running normally. In that situation, one option to consider is extreme shoe modification that goes beyond Modified Nike Free. You may have seen runners at ultramarathons with the top of the toe box cut away to relieve the pressure on blistered toes. I would consider that a moderate modification. Extreme modification is where parts of the sole of the shoe are removed to relieve pressure on a blister. This approach is not without significant risk. The pressure does not go away; rather you move it from one part of the foot to another. This means that while you may be able to reduce the problem from a blister, you can increase the pressure elsewhere, causing other blisters. You can also change the way the shoe supports your foot, causing biomechanical issues. Here are some examples of things I’ve tried.

1 Heel Blister

This modification was to remove the sole and upper on the inside of the left shoe. This worked well overall, and allowed me to run for several weeks while the blister was healing up. The downside was that I removed enough of the heel to put twisting stress on my foot and trigger a little Plantar Fasciitis.

2 Forefoot Blister

This blister was much harder to deal with, as the forefoot pressure is harder to avoid. My first attempt was to cut a hole in the forefoot with a margin around the blister area. This did not work, as too much of the shoe was removed, creating stress around the blister as the foot was squeezed through the gap.

2.1 Second Attempt

Cutting less of the shoe away was the next attempt. This was better, but started to feel like the blister area was being pinched. I think that the hole in the shoe was closing up as the foot lands.

2.2 Third Attempt

My third attempt was to just remove some of the midsole to reduce the pressure, without creating a hole that could close up.

2.3 Root Cause Analysis

The blister on my forefoot was caused by new callous rubbing. The presence of a callous indicates pressure or rubbing in a spot, and my best guess is that it is caused by the shoe squeezing the side of the foot slightly. I therefore also removed most of the sides of the forefoot, to create more of a ‘running sandal’. So far this option is working well.