This past August I worked on the most horrific heel blisters I have seen in over 13 years of doing foot care. The event was the running of the Gore-Tex TransRockies Race over six days in the Colorado Rockies. The daily distances ranged from 13 to 24 miles. The course was over trails and fire roads and many were steep. It was not a particularly wet course.
While there were many other blisters, heels and toes and ball of the foot, the heel blisters on many of the runners were impressive. In this first picture, you can see how the forward most edge of a blister has torn and opened up across the whole bottom of the foot.
Looking closely, you can see that the blister’s roof is thick, at least four layers of skin. It doesn’t mean that this is a blister under a callus. The second photo from a different angle allows you to see the blister covers the whole heel, side-to-side and to the back of the heel.
Up to that point, I had only seen this type of blistering on one runner. That was during the 2008 Badwater race in Death Valley. I attended to him at mile 21. He had bilateral heel blisters as shown in these photos. His history was interesting in that he had vacation in Tahiti on the beaches and just before Badwater had hiked down and back up the Grand Canyon. I theorized that the rough sand coupled with the heat on the beaches, followed by the friction of the steep ups and downs of the Grand Canyon, made his heels susceptible to blistering on the hot roads of Badwater.
Then I saw not one runner at the TransRockies, but more than 15 runners with these same blisters! The blisters were on men and women, of all body weights, and of all running speeds. They even affected a few of the race leaders.
The third photo shows a heel blister that tore on the side of the foot. I removed the torn skin because of the condition of the torn part. Leaving it on would have not provided any protection.
At the TransRockies, I talked to David Hannaford, a sports podiatrist from California who was running the race. He speculated that the footwear or the insoles could cause the heel blisters. My feeling is that the blister formed deep under several layers of skin due to a combination of steep downhill running and pressure/friction created when the runner landed on his/her heels. As the runners ran the steep downhills, with their full bodyweight landing on their heels, the added pressure and friction led to the blisters forming deeper then normal. While the coarse was not unusually wet, the feet have hundreds of sweat glands and the sweat typically generated while running could have also been a contributing factor. Many of the runners had these blisters bilaterally on both heels.
The next time I see these blisters, I will ask the runners what type of socks they were wearing. Socks with less moisture control will trap the wetness under the foot and can contribute to softened skin and blistering. I will also look at and feel the insoles. The surface fabric of some insoles is rougher than others and might be another contributing factor.
A good question is why some runners had these heel blisters and not others. It cannot be narrowed down to one thing. Here are my thoughts on possible contributing factors:
1. The steep downhills
2. The shorter day’s distances meant that runners could run fasted than those doing longer races, meaning the downhills were run faster
3. The type of socks they were wearing
4. The surface of their insoles
5. How they landed (heels versus more on the whole foot or forefoot)
6. How much their feet sweated
7. Any pre-existing conditions as calluses or new skin under previous blisters
8. The fit of their feet inside their shoes (allowing extra movement)
9. The use of a lubricant on their feet, which can lead to softened skin
10. A lack of training with enough miles on the feet to warrant running such distance on a back-to-back daily basis
So there the 10 factors I feel could cause such extreme blisters. As you might guess, any one, or several, of the above factors, could have caused these blisters. One person could have been affected by factors that did not affect another runner. Several of the factors, such as numbers 1 and 2, were more than likely factors in a majority of the cases.
My next post, Part II, will detail how I managed the blisters and show photos of the process of patching them, what I learned and how I would manage them the next time.
