p***r
发帖数: 4859 | 1 http://www.runblogger.com/2012/04/effect-of-step-rate-on-lower-
Just over a week ago Amby Burfoot wrote a post about a new study from Japan
that provides additional evidence supporting the benefits of a shorter strid
e for reducing loading of the lower limbs. The study by Hobara et al. is tit
led Step Frequency and Lower Extremity Loading During Running and was publis
hed in Orthopedics and Biomechanics. I thought I’d follow up with a few tho
ughts of my own.
In the study, Hobara et al. wanted to determine how increasing or decreasing
step rate would influence vertical impact force and vertical impact loading
rate during foot strike (see first peak on the image above or read this pos
t for a detailed discussion of these variables). Vertical loading rate has b
een linked to some types of running injuries (e.g., stress fractures), and t
he idea was to determine whether altering stride rate could lead to alterati
on of loading, and thus possibly reduce injury risk.
The study itself was fairly simple. They had 10 subjects run on an instrumen
ted treadmill at 2.5 m/s (about a 10:45 min/mile pace) at five different ste
p rates: freely chosen step rate, and –30%, –15%, +15%, and +30% of the fr
eely chosen step rate. Modifying step rate at a constant pace results in a c
hange in stride length, so increased step rates lead to a shorter stride, an
d decreased step rates lead to a longer stride. The researchers monitored pe
ak impact force, instantaneous vertical loading rate (VILR; this is the peak
loading rate observed during impact), and average vertical loading rate (VA
LR) as each runner ran on the treadmill.
Results are pretty well summarized in the following figure adapted from Hoba
ra et al. 2012 (any errors in reproduction are my own – I recreated it to a
void copyright issues):
Hobara Figure
The stars in the above figure indicate values that are significantly differe
nt from that observed at the –30% step frequency. This implies that running
with a really slow step rate/long stride significantly increases impact for
ce and the rate at which that force is applied. Though there appear to not b
e significant differences among the other stride frequencies, a quadratic re
gression analysis found that impact peak, VILR, and VALR were all minimized
at a step rate of roughly 17-18% higher than the freely chosen step rate (i.
e., this is the low point of the black curved lines fit to the sample data f
or each step frequency). Data for individuals were unfortunately not provide
d.
This is not the first study to suggest that a shorter, quicker stride might
be beneficial when it comes to reducing loading of the lower limb. Others ha
ve found similar results (e.g., read this post on stride length and leg join
t loading), and the topic has received a lot of attention of late. In fact,
I wrote an entire chapter on the topic in my forthcoming book that summarize
s historical advice on stride length as well as what modern science has to s
ay about the topic. I’ve come to the conclusion that stride length is likel
y one of the more important form characteristics to consider when it comes t
o reducing injury risk. Though there is a great deal of debate about proper
foot strike, most people seem to agree that overstriding is bad, and there a
ppears to be some solid science backing this up.
Limitations of this study are that it’s difficult to say whether the result
s are generalizable to runners across a range of paces (all ran at a 10:45 m
in/mile pace here). It’s also difficult to know whether treadmill-derived r
esults are applicable to overground running. Nonetheless, the fact that thes
e results are consistent with previous research on the topic adds further su
pport for the use of stride length modification as one potential tool in the
prevention and treatment of running injuries. | c*********n
发帖数: 2120 | | t*********t
发帖数: 4766 | 3 有人翻译一下吗。怕一下看睡着了。
Japan
strid
tit
publis
tho
decreasing
loading
pos
【在 p***r 的大作中提到】
: http://www.runblogger.com/2012/04/effect-of-step-rate-on-lower-
: Just over a week ago Amby Burfoot wrote a post about a new study from Japan
: that provides additional evidence supporting the benefits of a shorter strid
: e for reducing loading of the lower limbs. The study by Hobara et al. is tit
: led Step Frequency and Lower Extremity Loading During Running and was publis
: hed in Orthopedics and Biomechanics. I thought I’d follow up with a few tho
: ughts of my own.
: In the study, Hobara et al. wanted to determine how increasing or decreasing
: step rate would influence vertical impact force and vertical impact loading
: rate during foot strike (see first peak on the image above or read this pos
| t*********t
发帖数: 4766 | 4 这篇的结论好象有点费话啊。快频当然跳不高。慢频当然要跳高点才能慢点落地。
Japan
strid
tit
publis
tho
decreasing
loading
pos
【在 p***r 的大作中提到】
: http://www.runblogger.com/2012/04/effect-of-step-rate-on-lower-
: Just over a week ago Amby Burfoot wrote a post about a new study from Japan
: that provides additional evidence supporting the benefits of a shorter strid
: e for reducing loading of the lower limbs. The study by Hobara et al. is tit
: led Step Frequency and Lower Extremity Loading During Running and was publis
: hed in Orthopedics and Biomechanics. I thought I’d follow up with a few tho
: ughts of my own.
: In the study, Hobara et al. wanted to determine how increasing or decreasing
: step rate would influence vertical impact force and vertical impact loading
: rate during foot strike (see first peak on the image above or read this pos
|
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