Friction is unmistakably a part of what causes blisters. This is bad friction.
But friction is also good. In fact, it's vital to the way you walk, run and play. You'd be lost without it.
First, let's agree on the definition of friction
Friction has a double meaning in the English language. Most people think of friction as "rubbing". I want you to forget about this definition, just for now.
Scientists know friction as "the force that resists movement". It's a force that keeps one surface in stationary contact with another.
Low friction means slippery. High friction means grippy - things tend to stick together.
Your biomechanics relies on friction
Friction is good, for the most part. Friction equals traction. Your foot needs traction for the mechanical efficiencies of gait. It’s necessary for propulsion and acceleration. It’s necessary for efficient deceleration and for rapid changes in direction. Traction is necessary for the efficient transfer of weight from one foot to the next, whether you’re running (or walking) on an incline or a decline, on flat or uneven surfaces, in a straight line, in circles or dodging obstacles. Without it, your toes would jam into the toebox of your shoe, giving you black toenails. It would make you more susceptible to injuries like ankle sprains and proximal muscle strains. And it will make you work harder to produce the same speed. If your foot slips and slides around in your shoe, it's a bad thing.
So where do you get traction from? You get traction from high friction levels, from things gripping together.
Good friction, bad friction
So friction is good. But it can be bad when we get blisters. The important thing to realise is that friction is necessary and is why your shoes, socks and insoles are made out of high-friction materials. It’s only when high friction levels are giving you blisters that you need to manage that friction – and only in that discrete location. Not all over, just in the area of your blisters so you can maintain necessary traction.
ENGO Patches allow the targeted management of friction. You select the appropriate shaped patch (or you cut it to size) and apply it to the shoe. That way good friction is maintained everwhere else for traction.
Many blister prevention strategies reduce friction. But not all of them do it in a way that is targeted. Strategies that are not considered targeted include moisture-wicking socks, double socks, lubricants, taping (depending on application technique), powders. That's not to say these are bad choices for blister prevention. I highly recommend moisture-wicking socks. And taping has it's place. But if you need to be serious about reducing friction levels, you only want to make it more slippery where your blister is - not all over your foot. Or you'll end up with black toenails, ankle sprains or other injuries. And you'll expend more energy than you need to.
When it comes to blisters, think of friction this way. Shoes, socks and insoles are made of high-friction materials in an attempt to keep your foot still in your shoe. This is both intentional and appropriate. It stops your foot from sliding around in your shoe. But this doesn’t stop the bones from moving around inside your foot. Moving bones cause everything between the bone and skin to stretch (shear). When this occurs to excess, the connections between skin cells fatigue and a small tear develops under the surface of the skin. When fluid fills that tear (within two hours), you have a blister.
Don't let this happen. Reduce friction. But do it in a safe and targeted way that maintains necessary traction for your foot in your shoe.
- Friction is the force that resists the movement of one surface against another.
- Friction is necessary for traction. Traction is necessary to function efficiently.
- If you get blisters, don't reduce friction all over. Use a targeted approach.
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 both "The Blister Prone Athlete's Guide To Preventing Foot Blisters".