The current reality of blister prevention
The frustrating reality of blister prevention is it often fails. It can be difficult to find a strategy (or combination of strategies) that works, is long-lasting and is quick and easy to use. Several factors are at play here including the extreme forces encountered by the weight-bearing foot and the hot and humid in-shoe microclimate. But also:
- there are inherent limitations in each strategy that must be understood
- the misunderstandings of what really causes blisters can lead to an unsuitable prevention strategy being chosen
Chapters 5-7 will look at all of your blister prevention options. One by one, we’ll look at how the strategy works, its pros and cons and what research can tell us about its effectiveness.
LET’S TAKE A CLOSER LOOK AT FRICTION
But first, there’s one concept that’s generally missing from the mainstream discussion of blisters. We’ve touched on it, but you may not have realised its importance. If you can understand this concept, you will expand your repertoire of blister prevention options. The concept is that of interfaces.
Friction is present between any two surfaces. We call a pair of surfaces an interface.⁷³ The in-shoe interfaces are the skin-sock (black) interface and the shoe-sock (blue) interface, depicted below. When looking for blister prevention opportunities to do with friction, you need to get specific about which interface you’re looking at because it makes a difference!
Consider the black interface. By making it more slippery here, movement of the sock against the skin is encouraged. This rubbing in not necessarily going to be a problem to the skin – unless friction increases to a level that is abrasive. Strategies that work at this interface, like lubricants, powders and moisture-wicking socks will be explained in the following chapters.
Now consider the blue interface. By making it more slippery here, movement is encouraged between the shoe and sock. The rubbing can’t cause abrasive skin damage because nothing is rubbing against the skin – the sock is protecting it. The sock is protecting the skin because the two are stuck together and remain in stationary contact (thanks to friction) while movement occurs on the other side of the sock. The following chapters will explain how this works – particularly polytetrafluoroethylene patches (ENGO Patches).
Figure 16: The two interfaces present in most athletic situation when wearing shoes and socks
BLISTER PREVENTION STRATEGIES
Next we’ll look at individual blister prevention strategies that you can employ, focusing at either your:
- Shoes and socks – including types of insoles, orthotics and patches applied to your shoes
- Skin – including moisture management techniques and tapes applied to your skin
- Activity – including your technique and the intensity with which you perform
- Blister prevention fails when the wrong strategy is chosen for the activity; and when the inherent limitations of the strategy are not understood.
- Friction exists between any two surfaces (called an interface). Friction may be high or low.
- There are two interfaces in the shoe that are commonly used to apply blister prevention:
- Skin-sock interface
- Shoe-sock interface
- Friction reduction at the shoe-sock interface allows the sock to protect the skin from abrasion.