Thursday, June 09, 2011

Juneathon 2011 Day 9: Shoes and injury

2011 Streak Day 160/365; Walk - 7.15 miles, Time - 2hr 18min, Weather - changeable
Part 1 - More about shoes
One of the interesting things about the debate around barefoot running is the argument on injury. The proponents of minimalist shoes point to statistics that show the proportion of runners with injuries has not declined despite improvements in cushioning and trainer design since the 70s, which suggests that all the purported improvements have not really worked.  They also claim that studies sponsored by the shoe companies which show increased impact absorption are only proxy measures that do not translate into real life protection.
On the other hand the studies they like to quote which show reduced forces when landing on the forefoot are also proxy measures, which may or may not translate into real life protection.
So the situation is confused with no definitive answers about the link between shoes, running style, and injury.
It is very difficult to find the direct cause of injury because there are so many confounding factors. Even, as an individual, it is sometimes difficult to identify the cause of a particular injury. My recent knee problems are a case in point. I have no idea if they were caused by: running in worn out shoes, pressing too hard on hill sessions, the cumulation of not doing enough stretching, or having my cleats badly adjusted on my cycling shoes. All are possible (though I tend to favour the cleats - I don't think the injury was caused by running). It is possible it was a combination of things but it is also possible that it was the result of something more deep seated (the physio found that my hip was out of alignment).
The best types of studies for the effect of shoes on injuries are therefore likely to be epidemiological in type. One such was done on runners in the Vancouver Sun Run, a 10k which has about 60,000 entrants. The interesting finding was that injuries were more common when men ran in shoes older than 4 months and when women ran in shoes older than 6 months. So the degradation of cushioning is obviously important. (I will hastily pass over the fact that age is is the main factor associated with injury).
However there is always a place for the study looking at a specific factor. One I find particularly interesting seems to suggest that the attention paid to matching degrees of pronation to either neutral, stability or motion control shoes, is misplaced. Motion control shoes caused the most pain to everybody but the eye catching finding was that neutral runners had less pain in stability shoes than in neutral shoes and pronating runners had less pain in neutral shoes than in stability shoes. Although the study has limitations of sample size and of being only of women (I don't know if that makes any difference) there is a clear implication some of the basic assumptions about trainer choice are not well founded.
The unsurprising conclusion is that things are never simple, never clear-cut. But we have to have something on our feet (unless, of course, you are a barefoot purist). Personally I am pragmatic and choose shoes that fit the best and seem the most comfortable, everything else I ignore.
Part 2 - The Walk
I had the idea that my pictures have neglected animals this June, so I walked to and around Boxmoor, where cattle and horses graze. I then walked further along the canal before looping back home. During the walk I had a wonderful sense of the abundance of nature: meadows full of buttercups, hedgerows thick with variety, trees in full leaf, and birds singing. However my day was made when I saw a heron standing stock still beside a bush, in a field. I have only ever seen them in flight or by the water before. I don't know what it is but there is something I find quite appealing about the way heron stand and look-around.
Unfortunately I could not get near enough to take a picture of the heron but cows are good. They are very tolerant of people walking up to them.

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