The 4 Key Challenges to the Advancement of Friction Blister Management

Foot friction blisters are one of the most misunderstood sports and foot health issues. They’re not superficial-to-deep wear injuries, or burns. Rather, they are an intraepidermal tear caused by repetitive shear deformation. This distinction is critical for both prevention and treatment.

Problem 1: The Word “Friction”

One of the biggest obstacles in blister management starts with the word “friction” itself. It has two opposite meanings:

• Lay definition: rubbing
• Scientific definition: resistance to rubbing

This confusion has led to entrenched misconceptions—many still believe blisters are caused by rubbing, heat, or wear, and that callouses are obvious topline preventions. In reality, blisters occur when bones move inside the foot while the skin surface remains stationary (due to high friction force), stretching and distorting the soft tissues in between until fatigue injury occurs.

Problem 2: Misconceptions Perpetuated in Academic Literature

Experimental blister research as far back as 1955 (Naylor) and 1966 (Salzburger et al) clearly identified repetitive shear deformation as the cause of blisters. Comaish put this beyond doubt in 1973 – over fifty years ago!

Despite this, academic papers—even recent ones—still describe blisters as abrasions from rubbing. FRom reading the research over many years now, understanding has actually regressed, from around the 1990s and early 2000s, making this a persistent challenge for health professionals.

Problem 3: Inability to Measure Shear

Another challenge is that shear—the real culprit—cannot yet be measured at discrete anatomical sites, unlike pressure.

Problem 4: Limited Evidence Base

When it comes to prevention strategies, the evidence base is limited. Some interventions, like familiarity with footwear and activity, densely padded acrylic socks (compared to cotton socks), and 3mm neoprene (Spenco) insoles, have demonstrated support. Antiperspirants and powders have been shown to not work. We have mixed evidence for paper tape and double socks. Finally, popular options like lubricants, other types of tapes (Fixomull Stretch, rigid sport tape, kinesio tape), pressure-deflective padding, and even optimised shoe fit have not been put to the test. Nor have moisture-wicking socks. Strategies that I rely heavily on, like gel toe protectors and ENGO Patches have similarly not been put to the test in research, although there may be some laboratory research proposing a blister prevention mechanism, such as moisture management.

Moving Beyond Heat, Moisture, and Friction

An effective blister prevention framework starts with understanding what shear is, why it happens and how to reduce it. This means shifting the focus away from the traditional “heat, moisture, friction” model and toward the repetitive shear deformation paradigm.

Applying the Framework in Practice

When applied to real-world cases, this framework can be highly targeted. Watch the video for a discussion of the different preventions you can put in place for a blister under the first MPJ when there is a plantarflexed first ray.

Question 1: Recurring blisters in children’s soccer boots

Successful blister management isn’t about matching preventions to sports—it’s about matching them to anatomical sites. More information is needed about where the blister is happening to be able to answer this question.

Question 2: Ultramarathon runner with a blister under the second toenail

One of two things is causing this blister:

• The toes are hitting the end of the shoe: Assuming the shoe is the correct size to start with, take the insole out and see where the toes are imprinted. You need a thumbs-width between the end of the toe and the end of the shoe. Any less than that shows the foot is moving forward in the shoe. Firm lacing is the answer.
• Digital clawing: Reduce digital clawing with toe props. I suggest people:
  • Get some felt and experiment by add layers until the appropriate level of bulk is attained – something that’s comfortable, but keep the tip of the toe from bearing significant weightbearing force.
  • Get an off-the-shelf toeprop and see if that is too bulky, not bulky enough, or just right.
  • Finally, take what you’ve learned above about appropriate bulk of the prop to a podiatrist and get a couple of Otoform K toeprops made.

What’s Next?

If this all sounds a bit daunting and you need some direction on understanding the mechanisms of action, pros & cons and ideal useage scenarios for all the different preventions out there, take a look at Blister Prevention University. Developed in collaboration with Doug Richie, Blister Prevention University gives health professionals a deep dive into prevention strategies, their evidence base, mechanisms of action, and how to apply them to specific foot locations. With better understanding and targeted solutions, we can move past the misconceptions that have held blister management back for decades.