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Converse All Star Chaussures

in News 20.05.2016 14:54
von jie123 | 62 Beiträge | 5580 Punkte

Finally, I All Star Converse High Tops Pas Cher teach comparative anatomy, and this has some bearing on my thoughts about where footstrike should occur. When you look at cursorial (running) animals, what you often find is that over evolutionary time their ¡°heels¡± have become raised up off the ground. Dogs run on their toes (digitigrade), and horses run on the tips of their toes in the form of a hoof (unguligrade). They do this because it allows them to essentially lengthen their legs, and they have slender distal limbs with many long tendons and ligaments. If one is to believe the theory that humans are/were on a path to becoming distance running specialists, would it not be a logical hypothesis that we were also moving in a direction quite similar to other running animals? We have long Achilles tendons compared to chimps, and an arched foot supported by the plantar fascia. As Magness states above, storage of elastic energy is more effective with a forefoot strike than a heel strike, and most of us will automatically convert to a forefoot strike after running barefoot for a time (sometimes instantly).

As I have written previously here on Runblogger, forefoot striking has been shown to reduce vertical impact peak (many studies, Squadrone and Gallozi, 2009 and Lieberman et al., 2010 are recent examples) and vertical impact loading rate (Oakley and Pratt, 1988; Williams et al., 2000) relative to heel striking. Data showing no difference between forefoot and rearfoot impact loading rate is out there (e.g., Laughton et al., 2003), but data are limited that involve people well acclimated to multiple landing types. Data on loading rates are sometimes difficult to interpret if runners are not Converse American Flag Pas Cher acclimated to a barefoot running style ¨C for example, De Wit et al., 2000 showed dramatically increased vertical loading rate in barefoot runners compared to shod runners, but their barefoot runners were heel striking. One would fully expect a barefoot heel strike to exhibit a higher loading rate since little cushion other than the heel fat pad is present to slow down force application. Lieberman et al., 2010 showed that habitually barefoot runners overwhelmingly land on the forefoot, which suggests caution when interpreting studies of barefoot heel strikers (who were probably unaccustomed to running barefoot). See this recent (2011) paper by Jenkins and Cauthon in the Journal of the American Podiatric Medical Association for more on this issue.

How about the series of studies by the military (Knapik et al., 2009; Knapik et al., 2010a; Knapik et al., 2010b) which showed that when assigning shoes based upon arch type, recruits (thousands of them were included in these studies) were just as well off being assigned a stability shoe by default as they were being put in the correct type of shoe for their arch type. So much for that wet test ASICS!

Bartold goes on to cite a reference by researchers from the University of Massachusetts that reports ¡°a 7% decrease in running efficiency in the barefoot group in a model predicting barefoot vs shod running.¡± I¡¯m not sure exactly which paper he is referring to, but if it¡¯s the one I think it is, it¡¯s a conference abstract in which a computer model was developed based on measurements from a single individual. No oxygen consumption measures from living human beings were involved. So, the two-dimensional computer model based on one person referred to in an unpublished conference abstract ran better on its heels¡­not sure I consider that to be strong evidence. Jenkins and Cauthon (2011) summarize a number of studies which have shown reduced oxygen consumption in barefoot running compared to shod running. However, to be fair, it¡¯s quite possible that this is simply a mass effect since removing shoes removes weight from the end of the limb. Squadrone and Gallozzi (2009) found oxygen consumption to be lower in in experienced barefoot runners running in Vibram Fivefingers vs. traditional shoes, and noted that running in traditional shoes resulted in significantly greater dorsiflexion of the foot on landing (i.e., they were heel striking, albeit mildly). Interestingly, barefoot was not significantly more efficient than either traditional or Vibram Fivefinger running (i.e., it was in between the two). The efficiency question might just be a wash, but I don¡¯t think we can really say either way with any great degree of certainty at this point.

Anyway, yesterday he posted a comment by ASICS hea Converse Chuck Taylor Pas Cher d of research Simon Bartold in which he essentially refers to the minimalist running movement as ¡°nonsense,¡± and says this about ASICS future running shoe plans:

Surely the folks at ASICS must be aware of the paper by Ryan et al., 2010. They showed that neutral runners did better in stability shoes, overpronators did better in neutral shoes, and all severe overpronators in motion control shoes got hurt. In other words, either the shoes don¡¯t do what they are supposed to, or static measures of the foot are not a good basi Converse Limited Edition Pas Cher s for assigning shoes. And the study was supported by Nike.

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