p***r
发帖数: 4859 | 1 ☆─────────────────────────────────────☆
wolfstar76 (天狼星) 于 (Thu Oct 22 20:30:05 2009, 美东) 提到:
http://www.sportsscientists.com/2008/04/running-technique-foots
zt 如下：
Running technique: The Footstrike
Heel vs. Midfoot vs. Forefoot: How do elite runners land?
I've finally gotten around to this post, which is probably two weeks in the
making, and it follows on from our recent series on running shoes. That
series began by looking at whether shoes are in fact as much a cause of
injury as a cure, and then evolved into a discussion of how the running
market is evolving. Twenty years ago, it was all about motion-control shoes
preventing overpronation to prevent injury. Today, it's all about running "
barefoot in your shoes", as companies try to go back to "natural" without
selling you "the Emperor's clothes", in effect! (It's quite a long post, my
apologies, but a lot of important information to get through...)
The next logical question is to ask how is the foot supposed to land during
running? This question evolves out of the discussion of shoes. vs barefoot
running, and is often at the heart of discussions on running technique. Very
often, debates of "technique" tend to start from the feet, jump to the
knees ("lift your knees") and then skip to the arms, and that's about it! We
won't go into too much detail on technique today, focusing instead on only
one of many aspects - the landing of the foot, and particularly, whether the
elite runners tend to land on the heel, the midfoot, or the forefoot.
Elite runners footstrike patterns
Perhaps surprisingly, there are very few studies looking at elite runners
and footstrike patterns during actual races. Despite this, until recently,
the overwhelming majority of coaches and experts were advocating that heel-
striking was the most effective technique, simply because most athletes did
it. That claim will come up again, but the perception that it was most
effective has, over the last few years, been changing. And with the advent
of Pose and other running techniques, as well as the observation that not
all elite runners are landing on the heel first, people have now begun to
advocate that forefoot landing is better! So we have this 180 degree shift,
often in the absence of any substantial data to support the claim.
I am sure that many will have seen this kind of assertion (this one is from
Wikipedia):
Leaning forward places a runner's centre of mass on the front part of
the foot, which avoids landing on the heel and facilitates the use of the
spring mechanism of the foot. In other words, landing on the heel is bad, to
be avoided...
Or there is this, from Gordon Pirie (admittedly somewhat older):
"Running equals springing through the air, landing elastically on the
forefoot with a flexed knee..."
But what is "better"? Where science has yet to catch up with opinion
It's important at this point to ask the very pertinent, but infrequently
asked question: "What does 'better' mean?". In other words, when people are
advocating that it's 'better' to land on the forefoot, what do they mean? Is
it faster? More efficient? Less injury-prone? The fact is, the word "better
" is used without studies specifically looking at any single one of these
aspects. And the 'prudence concept', as applied to science, says that you
cannot say something is "better" unless it's been studied and compared to
the alternatives. Unfortunately, the science lags behind in this regard.
So for example, above you have the quote that you are supposed to land
elastically on the forefoot. That implies performance and efficiency, which
might be true for short exercise, lasting a minute or two. But in an event
like the marathon, are we sure it remains the "better" option? If you went
out and ran 2 hours today, landing on your forefoot instead of landing as
you've always done, what would be the likely outcome? Chances are, you'd be
hurting for a few days, with calf muscles that you had perhaps forgotten you
had! Worst case scenario, you'd be injured for months with an Achilles
tendon injury. That is certainly not a desirable outcome. So there are
problems with making sweeping statements about landing patterns.
But more than this, these kinds of statements are never grounded in proof.
So for example, when it's written that you land "elastically", has anyone
ever done the study of elastic energy return in different types of running?
They haven't, but there is theory about it, and that's where these
recommendations come from. So the approach in the discussion that follows is
for me to adopt the role of "questioner", playing Devil's Advocate, with
the humble admission that science simply does not know the right answer,
only the possibilities...
Looking at one particular study - elite 21 km runners
So in the current climate where real evidence is scarce and opinions hold
sway, let's take a look at one study that has examined footstrike patterns
during running events. It was done in 2004 in Japan, and published in 2007
in the Journal of Strength of Conditioning (not sure of the reason for the
delay - it happens sometimes in science!). The full reference, for those
interested, is Hasegawa et al., J Strength & Cond., 2007, (21), 888-893
It was performed at the 2004 Sapporro International Half Marathon in Japan.
The scientists set up a high speed camera (very important for accurate
collection of information - beats YouTube science any day!) at the 15km mark
of the race, and captured most of the runners coming through. In total,
they were able to observe the foot strike of 248 men and 35 women, and
characterize them as either heel-strikers, mid-foot or forefoot strikers.
They also measured Ground Contact Time at the 15km point.
The finding - what do you expect?
Before giving their main finding away, take a moment to guess what they
would have found...If you are anything like me, and have read the
substantial amount on the internet and in books about how it's "better" (
there's that word again) to land on your forefoot, then of course, your
expectation might be that they found:
* The majority of runners land on the forefoot
* Those that DO NOT land on the forefoot are the runners who finish
towards the back of the field
Well, if that's what you thought, you'd be completely incorrect...! Because
the finding is the following:
* The vast majority (75%) of the elite runners land on the heel
* About 1 in four (24%) runners landed on the mid-foot
* Only 4 out of 283 runners landed on the forefoot
Those runners that landed on the forefoot did not finish in the first four
positions, so the common argument (a flawed one) that the best athletes are
forefoot strikers is not supported by this finding.
Possible conclusions - how you read the study is influenced by what you wish
to prove...
So, given this, one is tempted to say that the landing of the foot makes no
difference to overall performance. Of course, this is not necessarily true.
As I wrote above, science is often taken out of context, and this is one
such example. You cannot, for example, rule out the possibility that these
heel-strikers might be a few seconds or minutes faster if they just learned
to land on their forefoot! Personally, I think that's highly unlikely, and
what is more likely is that they'll end up in rehab for Achilles injuries,
but even that is a "bald assertion", based only on opinion!
Now, however, here is where it gets interesting, and this is where the
forefoot advocates got quite excited. When the researchers divided the
finishers into groups of 50, they started to see something of a change in
mid-foot landing as you moved further down the list. In otherwords, there
was a higher percentage of midfoot strikers in the first 50 runners than in
the second, and then third, and so on. The graph below shows this for heel-
strikers and mid-foot strikers (I haven't shown forefoot, because it's so
tiny and insignificant by comparison):
At first glance, the conclusion from this graph is that if you want to be a
faster runner, finishing higher up in the overall order, then you should be
a midfoot striker, not a heel-striker. That's how many people interpreted
the finding. And this may well be true. Unfortunately, there is another
possible reason it looks like it does - perhaps it's simply a function of
running faster.
Speed and footstrike
In otherwords, you naturally shift your contact point with the ground
further forward when you run faster. The average speed, incidentally, of the
first 50 runners was 3 minutes 3 seconds per kilometer. The second group of
50 runners averaged 3 minutes 10 seconds per kilometer. Hardly a big
difference, but given the range (the 50th runner is at least a minute behind
the 1st runner), is it possible that groups of 50 is too big, and that all
this "finding" represents is a speed effect on footstrike?
The point is, this study does not allow you to differentiate between three
possibilities:
1. Faster runners are midfoot strikers (could be co-incidence or some
other cause); or
2. Midfoot strikers are faster runners (and therefore we should all
change our running style and land on the front part of the foot more); or
3. All runners would eventually be midfoot strikers, if they just ran
fast enough!
This is another classic example of how a scientific result can be taken out
of context and applied to give advice that may not be 100% correct.
Personal opinion and implications of this study
My personal reaction to this research, when it came out, was that it
disproved the popular theory that all runners should be aiming to become
midfoot or forefoot strikers. Most of us (well, I'm in this group, apologies
if you are not) are nowhere near the elite level, and we're often told by
experts and coaches that the elite are landing on the ball of the foot or
the midfoot, and so we should too.
But the next time you think of running like Gebrselassie and trying to land
mid or forefoot, consider this: if you go out and sprint 100m, you're likely
to run on your toes the whole way - because you're running faster, you land
more on the mid-foot, or even the forefoot.
Sprinting as you are, you'll probably cover 100m in 14 seconds, which puts
you only 1 second ahead of a Bekele or a Gebrselassie in a 5000m race, so is
it any wonder they are midfoot strikers on the track - they're running as
fast as most of us sprint? The point I'm trying to make is, if you ran the
speed they did, you'd be a mid-foot striker too! But just as I suspect they
change as they slow down, we all do. So why, and on what basis, should you
try to run with the same foot strike when you are running perhaps 3 minutes
per kilometer SLOWER than them? Again, these are relatively bald assertions,
but hopefully you recognize the implication of speed on foot strike.
So when you go out and run a 3 hour, or a 4 hour marathon, that's another
story altogether. And what the Pose running study at UCT showed me a few
years ago is that if you change the landing of the foot, you predispose the
athlete to injury - that study took a group of runners and within two weeks
had them all running on the midfoot (please don't write in to say that Pose
doesn't mean midfoot, because Romanov was the coach and he was happy with
their technique!). Two weeks later, they all broke down with Achilles tendon
injuries!
Why? Because sitting where you are right now, if I was to walk into your
office or your home and take you outside and ask you to please run landing
on your forefoot or midfoot, I can pretty much guarantee that the way you
would achieve this is to point your toe down...you're probably doing this as
you read this - contract the calf, and point your toe away from your body,
like in ballet. Now imagine your body weight landing on that contracted calf
muscle 85 times a minute for 4 hours. That, simply put, is a recipe for
disaster.
However, if you can gradually change your landing, then I do believe that
you can shift your footstrike. But it's a gradual process. And more
important, what is the point? There is no evidence that heel-strikers are
injured more, no evidence that mid-foot runners are faster and perform
better than heel-strikers, and so the ultimate question is:
Why would you want to change your foot landing to begin with? Science has
little to offer you in support of this. And so my advice, having read this
far (well done!), is to forget about the possibility that you're landing "
wrongly", and just let your feet land where, and how they land, and worry
about all the other things you can when you run!
If there is one thing you change in your running, don't focus on your
footstrike, but rather on WHERE your feet land relative to your body.
Because if you are over-reaching and throwing your foot out in front of you,
that's a problem, but what happens when the rubber meets the road is less
relevant!
I'm sure there's more to this topic, based on your questions and comments.
As usual, fire away! And remember the humble admission from earlier -
science, believe it or not, does not know the answer definitively! (just as
we can't tell you why Bekele is so dominant in World X-Country!)
Ross
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wolfstar76 (天狼星) 于 (Thu Oct 22 20:31:12 2009, 美东) 提到:
the
shoes
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timmy9 (过客) 于 (Thu Oct 22 21:36:29 2009, 美东) 提到:
我就把我的跑步姿势从heel striking改成ball landing. 促使我改的原因是跑步膝盖
痛。我看了网上关于pose method of running的讨论，觉得make sense. 不过第一次跑
后，痛苦不堪。我傻傻地跑了5miles. 一个多星期，archilles tendon 和calves走路
都痛。但这不是ball landing的错，是我archilles tendon和calves太弱。现在跑了两
个多月，长跑也能到10mile. 跑完后，archilles tendon和calves有些紧胀，正常的酸
疼，但膝盖却没问题了。
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mark (花生，微爷远爷的爸爸) 于 (Thu Oct 22 21:48:06 2009, 美东) 提到:
AT可以跑跑就变强么？
ball landing肯定对膝盖有好处。但是对脚跟和小腿又是挑战了.
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destyl (destyl) 于 (Thu Oct 22 22:30:04 2009, 美东) 提到:
我觉得可以。我也是从heel landing改成ball landing，花了半年多吧，开始时痛苦死
了，不止是calf muscles, 还有脚面也疼，慢慢就好了，我觉得我的calves 比去年强
多了。改成ball landing不但膝盖不疼，ITB也没出什么问题。而且我觉得用ball
landing的另一个好处是它可以强迫你更加注意running form, 因为ball landing时，
只有上身挺直，重心刚好落在脚的着地点，以及paw back时才是最省力的。
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wolfstar76 (天狼星) 于 (Thu Oct 22 22:51:35 2009, 美东) 提到:
我是表示怀疑这篇文章的发现：75%的elite runner居然是heel striker
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winndixie (because of) 于 (Fri Oct 23 12:11:29 2009, 美东) 提到:
I had similar experience as you ever since I practice mid-foot strike, which
is "just behind the ball" landing. I had knee pain, ITBS, and ankle problem
before. Now they are all gone. I still need to learn how to avoid sore
quads, but it is something I can deal with not like the above mentioned
injury. I think it is not just foot strike issue, but overall body posture
and running form we need to pay attention to.
Here is Danny's blog on mid-foot strike I found very helpful.
http://chirunning.com/blogs/danny/tag/midfoot-strike/
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Meltaways (绿袖子) 于 (Sat Jan 9 21:50:36 2010, 美东) 提到:
结论是？ | L********e
发帖数: 1202 | 2 Just wondering about this these days: If one has good running form and does
not heel strike, is there any harm to use cushioned but flat shoes? Is
cushion itself good or bad?
the
【在 p***r 的大作中提到】
: ☆─────────────────────────────────────☆
: wolfstar76 (天狼星) 于 (Thu Oct 22 20:30:05 2009, 美东) 提到:
: http://www.sportsscientists.com/2008/04/running-technique-foots
: zt 如下：
: Running technique: The Footstrike
: Heel vs. Midfoot vs. Forefoot: How do elite runners land?
: I've finally gotten around to this post, which is probably two weeks in the
: making, and it follows on from our recent series on running shoes. That
: series began by looking at whether shoes are in fact as much a cause of
: injury as a cure, and then evolved into a discussion of how the running
| R*****s
发帖数: 41236 | 3 我觉得还是需要cushion的， 你看elite也是穿racing flats跑，而不是光脚
或者VFF。。。。
does
【在 L********e 的大作中提到】
: Just wondering about this these days: If one has good running form and does
: not heel strike, is there any harm to use cushioned but flat shoes? Is
: cushion itself good or bad?
:
: the
| L********e
发帖数: 1202 | 4 是啊。我也觉得不管哪，踩在地上还是硬生生的不舒服。还在和新买的Hatorri 拼呢。
【在 R*****s 的大作中提到】
: 我觉得还是需要cushion的， 你看elite也是穿racing flats跑，而不是光脚
: 或者VFF。。。。
:
: does
|
|
