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Running barefoot less impact because of evolution?

To run just one pair of shoes ... Perhaps not, according to D. Liebermann an evolutionist of Harvard, reported in Nature News by Buchen, Lizzie (2010) ( A Soft ride for barefoot runners ): we could run even better - more flexible in all cases - barefoot. It shows that those who run without shoes have long been a movement which runs over the foot and the impact forces produced more regular with fewer peaks. He even suggests that this may cause fewer injuries. I often think when they heard the high heels of a neighbor slam his office decided not on the hallway floor ...

Fig 1: The flexibility of movement "round" that place his foot would be more important than shoes to minimize impacts. [Img ] Source: F. Lombard Round the foot movement? In contrast to these aesthetic considerations that justify the high heels, a trend Which are part of a movement claiming the natural, but whose connection with the work of Liebermann is not clear. The results do not compare this type of shoe to others, but rather suggest that the flare must come from the movement of the foot and not the shoe that could not absorb a shock on the heel.

ergonomic recent appears to be the shoes to the shoe very rounded rocker sole

Fig 2: A trend in the shoe seems to be footwear soles rounded "rocker sole". [Img

] Source: Ryn: walkwithoutpain.blogspot.com The endurance race: a decisive factor in our evolution? In another publication, Bramble, DM & Lieberman, DE (2004) ( Endurance running & the evolution of Homo ) also defended the anchorage of the evolutionary race barefoot because we run barefoot for hundreds of thousands of years we have developed a harmony between foot structure and dynamics of the stride. We support the comparison pretty well for the endurance with other animals and our skeleton bears clear traces. Lieberman illustrates his point with a video when seen running barefoot on the snowy sidewalk. Thus the endurance race would be a decisive factor in our evolution, developed shortly after separation with chimpanzees and to have played a role in determining our structure. Let us detail the two buttressing their arguments and by the data. running barefoot to run smoother?

Fig 3: Those who are accustomed to running barefoot naturally cushion the impact by landing on the "palm" of the foot, rather than the heel. [Img ] Source: Rick Rycroft / AP Photo. Fig 4: Comparison of the dynamics of the foot during the running of riders used to run barefoot or shod. Riders accustomed to running barefoot (c) produce less peak forces during the impact of the foot on the ground (note the absence of a peak in the first 50 milliseconds) than those who are shod (b) or when Running barefoot runners accustomed to running shoes (a). The force of impact with the ground, even with a cushioned insole as high as three times the weight of the rider. Those who touch the ground from the front (FFS) that are not subjected to forces of 0.6x weight. [Img ] Source: Lieberman, DE, et al. (2010)

Lieberman and his team ( Foot strike patterns and collision forces in habitually barefoot versus shod runners ) performed a biomechanical analysis of endurance runners on a mat with force sensors, with runners who run barefoot for a long time (Used to run barefoot = HCPN) and accustomed to running shoes (HCC = ) as well as recent converts to the race barefoot. (Lieberman, DE, et al., 2010) Lieberman said that the first time a rider accustomed to running barefoot rushed on his aircraft, he was very surprised: the usual peak force during impact was absent. (Trad. personal) He then compared three groups of people: runners who long run barefoot (accustomed to running barefoot = HCPN), distance runners accustomed to running shoes (HCC), and distance runners accustomed to running barefoot running shoes (HCCPN) This comparison showed that those who long run barefoot (HCPN) produce impacts on the ground much softer: the foot hits the ground by the front-foot strike drills (FFS), rather than the heel rear-foot strike (RFS). The majority (75-80%) of runners accustomed to running shoes (HCC) impacting the ground tail first (RFS): it produces reaction forces of ground the order of 1.5 to 3 times the body weight during the first 50 milliseconds: the rise of brutal force is manifested by a peak in figure 4.a. We see that the riders HCPN produce forces that vary more regularly see Fig 4.c. If one looks only at the peaks of the first few milliseconds, measurements show that the impact force was 0.58 ± 0.21 body weights among regulars bare foot (HCPN) that place the foot (FFS), which is 3 times less than used to running shoes that impact on the heel (RFS) or when they run barefoot HCCPN (1.89 ± 0.72 body weights) or wearing (HCC) (1.74 ± 0.45 body weights). Lieberman, DE, et al. (2010)

Use flexion of the ankle to reduce the impact

Lieberman thus shows that the force of impact with the ground by the heel (RFS), even with a sole cushioning is much greater than in those that touch the ground from the front (FFS) (as HCPN) held the foot with flexion of the ankle - allowing muscles and tendons of the foot and calf to function as shock absorbers. He thinks this could explain the frequent injuries of the foot race, but Lizzie Buche said that the link has yet to be demonstrated. Bramble think the race roadway does not take advantage of opportunities in our depreciation and lower limb that increases the risk of injury. "Ignoring how we evolved and how our bodies are made to work is a dangerous game," he said.