Wednesday, May 19, 2010

Blisters Revisited

More and more here in Wyoming, the weather favors hitting the trails, and that makes it seem as if a few reminders on blister prevention (and a bit of fairly new data) could be in order. But first a pre-reminder reminder: blisters are formed where shear forces are at work, separating outer layers of skin from inner layers--and they probably form easiest on damp, hot skin. Logic would suggest, therefore, that anything to keep your feet dry and cool will help prevent blister formation. But that isn't true. Some things work, some don't. Reducing the shear forces on blister-prone sites, such as of course the heels of your feet, is preventitive and possible with moleskin and other products made especially to do the job, such as Blist-O-Ban. Lightweight liner socks that wick away foot moisture are also preventitive when worn beneath heavier socks. Tape can work, but blisters can form beneath tape, so beware. On the other foot, lubricating agents (such as petroleum jelly, mineral oil, glycerin) work for a brief period of time, about a hour, but then increase the risk of a blister by softening the skin. Drying powders seem like a good idea since they absorb moisture, but they typically clump and can form an abrasive surface--and are not recommended for most people. Antiperspirants work to prevent sweating, and some hikers love them on their feet, but whether they actually work or not to prevent blisters remains uncertain. And, finally, you are still wise to buy your hiking footwear late in the afternoon, when your feet are puffiest, and make sure your boots fit.