American Council on Exercise Evaluates Benefits of Vibram FiveFingers® Shoes ...

[Longboard]

I'm still wondering if the

I'm still wondering if the 50% that "heel struck" were really landing much lighter than they did shod, as Lieberman's study showed, rather than increasing their risk for injury.

The evidence of a heel first/simultaneous landing may be quite different than a true heel STRIKE (ouch!).

 

[Barefoot TJ]

So properly identifying what

So properly identifying what is taking place would be very helpful.

 

[Longboard]

Yes, like is it a light

Yes, like is it a light landing or a hard landing. As Scott would tell you, you know it when you feel it/see it.

Maybe he could be our landing judge and help to quantify this!

 

[Barefoot TJ]

He's a damn good pilot.  He

He's a damn good pilot. He can land a plane before the passengers even know they're on the ground. So why am I afraid to fly?

 

[Longboard]

Just a neurosis, same as any

Just a neurosis, same as any foot phobic.

Curable though!

 

[Barefoot TJ]

Ha!  How do you cure it

Ha! How do you cure it though? He said he would retro fit the belts with air bags for me, but still! Now he's pushing to go down to Destin this weekend, the kids have a four day weekend coming up. It would take 1 hour and 20 minutes. Or we could drive for 6 and a half. I don't like my options.

How old were your kids when they first started flying with you?

 

[Barefoot TJ]

We should probably move this

We should probably move this discussion to another thread.

 

[Longboard]

Yeah, but a GA in GA thread

Yeah, but a GA in GA thread on the BRS? Pub I guess.

I'm in.

 

[jackie hayes]

Longboard wrote:I'm still

I'm still wondering if the 50% that "heel struck" were really landing much lighter than they did shod, as Lieberman's study showed, rather than increasing their risk for injury.

The evidence of a heel first/simultaneous landing may be quite different than a true heel STRIKE (ouch!).

I'm fairly certain that's not what the Nature study is saying. Using the notation in the paper -- the habitually shod runners are still RFS, because Lieberman and his coauthors do separate out those who switch to a MFS (17% in US adults, 19% in Kenyan adolescents). The MFS is a full-foot strike (or close), while the RFS is still a true heel strike (see the note below Table 1: "RFS equivalent to heel-toe running; FFS equivalent to toe–heel–toe running").



Now it is true that the habitually shod individuals do adjust somewhat in the angle of the foot, so that it is slightly flatter than it was before. But it's still not close to the angle used by habitual barefooters. (Table 1 has all these data.) In other words, the heel is still taking a pretty direct hit. And that's borne out by the impact data in Figure 2. The impact force of RFS barefoot is not much different than RFS shod (statistically, no difference). So there's no improvement by that measure. And the mean rate of loading is dramatically higher in RFS barefoot runners. The total force is the same, but it hits much more suddenly.



So while RFS barefooters do compensate somewhat, it's not enough -- they are still landing much heavier than they did shod.

 

[Longboard]

jackie hayes wrote:So while

So while RFS barefooters do compensate somewhat, it's not enough -- they are still landing much heavier than they did shod.

So your saying that Lieberman's work shows that most shod runners that switch to barefoot INCREASE the shock to their joints?

 

[jackie hayes]

Longboard wrote:jackie hayes

So while RFS barefooters do compensate somewhat, it's not enough -- they are still landing much heavier than they did shod.

So your saying that Lieberman's work shows that most shod runners that switch to barefoot INCREASE the shock to their joints?

It depends on whether or not they switch to a FFS. If they continue to RFS, then yes, the shock is larger. But if they transition to a FFS, it is dramatically reduced. (I don't think there's any data on the shock of a MFS.)



In that study, the habitually shod runners tended to continue to RFS when running barefoot. But those who had worked to make the transition clearly could do so (75% of the habitually barefoot US adults were FFS -- I have to think virtually all of them wore shoes while growing up). So most transitioners do eventually run lighter. But it takes time to adjust and you can actually do worse than shod if you try to do TMTS.

 

[Barefoot TJ]

If anyone has any follow-up

If anyone has any follow-up questions about FFS, MFS, and RFS and the Nature study, we could pose them to Lieberman in an interview. I'm sure he would make himself available to us. Anyone interested? What questions do you have?

 

[Longboard]

My questions for himo the

My questions for him:

Do the majority of normaly shod people running barefoot for the first time on a hard surface for 10 minutes have increased shock to joints, decreased shock, or no change?



Is a barefoot RFS that's flatter than the typical shod RFS as was prevelent in the study among habitualy shod BFRunner subjects an acceptable landing for a BFR or is the MFS neccesary?

 

[Barefoot TJ]

I'd ask him what he thinks of

I'd ask him what he thinks of the survey/news article we are discussing.

Anyone else have some questions? We want to pose a few of them, so it's worth his replying.