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These pages about video techique analysis are not
intended for most skaters. They are intended for (a) researchers in the
physics and biomechanics of skating; (b) a few skating coaches who want
another set of ideas about what to look for in video analysis, or to try
to get more background in the physics and biomechanics of skating.
Spending lots of time reading and understanding this
will likely not make you a faster skater -- for several reasons
given under video in
learning.
If you want to get faster technique, spend
lots of time skating behind and alongside skaters who are faster than
you -- or find a good coach, which might mean going away to a special
weekend workshop. Many good coaches nowadays use video as a tool -- and
I think that's the right place for it: as one tool in an overall
coaching program.
So I think the only helpful use of these pages
for an athlete would be to: (a) see if this approach to using
video is roughly what you'd want; and (b) find a technique-coach who can
show they are experienced at shooting and analyzing video in this way --
or better than this way.
I've done lots of analysis of the physics of skating,
and written lots about it, but it's not easy to connect with it when
it's lots of words and static diagrams. I'm hoping that tying it to
video will make it easier to get into it.
I'm not any sort of coach or instructor, and I'm only a
little bit of a racer. I do enjoy trying new moves in skating, and I've
had some good training in the physics of the kinematics and dynamics of
human-like linkages. So that's what I focus on in these pages: the
physics of Power + speed in skating, and what it looks like in video.
I leave most of the mental images and creative exercise
drills and progressive learning stages to coaches + instructors.
I do say something about prioritization, but that's
based more on my estimates / guesses about which aspects of technique
are bigger or smaller gains in propulsive power output in physical Watts
(not prioritization in terms of learning progression).
After you use the ease of video analysis to
learn to see that different skaters are handling a check-point of
technique in a different way, you can more accurately observe that same
check-point in live skating without video.
Even if you don't agree with what's presented
in these pages as the best way to handle some technique observation
points, just getting better at observing them can be helpful for
coaching.
In most sports nowadays, video analysis is
used at the elite competitors to enhance their technique. Athletes at
non-elite levels start to expect it too.
also to watch videos of the world's fastest to
see small new moves and timing-changes that they are experimenting with
to gain advantage. The techniques of skating are very complicated, so
there are still opportunities for successful innovations. The next
development of technique might be a new move combined with a
modification of equipment -- and there are so many possible combinations
that you'd want a good knowledge of the physics to at least make a good
guess about which ones to start trying.
In the end, speed is determined by physics, so
at the highest levels of competition it is important to know what the
components of propulsive power (in Watts) look like in video.
Many aspects of technique for skating fast are
non-intuitive, and look very different in video than the mental concepts
the coach has been teaching. This could be confusing or even
discouraging. It can help if the coach gets "out in front" of the
process by helping skaters have their early encounters of themselves on
video in a guided context -- help skaters perceive their positive
fundamentals instead of only the obvious discouraging shortfalls -- help
skaters work on core skills that build power instead of only eliminating
moves that "look funny".
-
by suggesting new questions to study, related to
specific points of analysis.
-
measuring Forces associated with different points in
video analysis.
-
making theory about why certain moves shown in video
are more effective for higher speed for skaters in some situations.
I think most of the advice that most coaches are giving
is very helpful to most learning skaters.
I also know that some things in these pages here about
video analysis sound different from what some coaches are teaching --
and that will be confusing for some people. If I were good at resolving
other people's confusions, I'd be rich or famous. Instead I'll try
offering some context for the confusions.
Here's the main reasons for the differences:
The conscious mind is mainly good at things
like talking, planning, worrying. Its view of what's happening with body
moves is simplified and distorted. So getting the conscious mind
involved with skating is about as likely to mess things up as it is to
help -- unless it is carefully managed.
Many skilled experienced skating coaches have
found that the safest way to manage giving advice to the conscious mind
is to over-simplify, exaggerate, and sometimes distort. Video analysis
(at its current level of sophistication) does not play along with that
strategy. (Video does distort things, but in an a whole different
paradigm.)
Giving advice to a group of learning skaters
requires even more careful management of the multiple conscious minds.
Which usually requires even more simplification. Exposing video
of a skater in the context of a group of her/his peers does not strike
me as likely to be the most effective approach.
A key source of this complexity is that the
motion of skating is fully 3-dimensional. Unlike running or most
bicycling, in skating all 3 dimensions interact to create
propulsive power -- for example, pushing sideways thru the foot gets
converted into foreward motion power. Which means there's a whole lot
more possibilities for engaging moves and muscles to increase speed.
Scientific researchers (as of 2007) do not
have complete models of the complexity of how all the moves contribute
to skating power and speed. No one yet can really demonstrate
scientifically what the truly optimal skating motion is for any
situation. Likely there are new speed tricks yet to be created by the
next generation of racers.
Exposing the minds of learning skaters to this
complexity is more likely to be confusing than helpful for improving
their skating. (A key reason why these pages here are not intended for
most skaters).
Expecting most coaches to understand
the complexity is not realistic. It's more the province of scientific
researchers and a handful of coaches working with elite racers.
Here's some other reasons for some of the differences:
But sometimes that famous racer is just
repeating the (over-simplified, exaggerated) good advice she absorbed
from her first coach. Or saying what her conscious mind intends,
or feels (or thinks it remembers feeling) -- often a distorted or at
least simplified version of what's really happening objectively in the
muscles and joints. Or it's what the racer consciously works on in
practice sessions -- even if that's not exactly what's really effective
objectively for going fast to win a race.
What you learned from the famous coach really
is good advice for your conscious mind. Just don't be surprised if it's
different from what you see in objective video of that same coach
skating in a real race.
So when coaches try to apply their normal
intuition to guessing the answer, they sometimes get it wrong. Even
people who know physics tend to assume that how skating motions produce
and transmit power could not be that complicated -- so they cut
off their analysis early. Which sometimes works and sometimes does not
-- because the actual speed of person skating is determined by the full
3-dimensional full complexity of many human bones + joints + muscles
interacting.
Video analysis is only a small part of an effective strategy for
learning techniques to skate faster. There are some tricky
pitfalls from relying on video.
To try to help show the limited role of video in learning, here's
some of the other questions that need to be considered before
changing some aspect of a skater's motion based on seeing it in a video.
Suppose a move is identified in video analysis which
could be changed to improve skating power and speed. Here's some
questions that could be important for implementing that change:
-
Although the analysis of physics says that making
this change "normally" results in an improvement of propulsive
power, is this skater's style and approach different from "normal"
in ways that might lead to an unhelpful result from this change?
-
Is this a change of something that mostly just
"looks funny" in the video, or is does it deliver a significant
increase in propulsive power?
(It's not wrong to work on changing some skating move for
appearance's sake, but it's good to keep clear on which changes are
for which reason.)
-
Does this change fit with the larger learning
progression for this skater? or for the team? Does this skater have
the "prerequisites" for succeeding with this change? Or would it be
better focus on a different change which will have a smaller
immediate benefit in skating power, but serve as a foundation for
bigger improvements later?
-
What makes it difficult to learn this change? or
difficult to get an increase in power + speed after the change?
(If this change were easy to learn and immediately resulted in an
increase in power, most athletic skaters would already be
doing it. The trap of many uncoached athletes using video analysis
is they think if they see how their favorite champion racer does it,
then it will be no problem to make their muscles do the same.)
-
Are there other changes that need to be made at the
same time in order to get a significant gain in power from it?
(One obvious problem is that to increase propulsive Force in
skating, you have to manage both "ends" of it, action and reaction.
Subtler and harder is that the brain's unconscious muscle control
module might be secretly "in love with some other moves which block
the effectiveness of this change.)
-
Are there other skaters on the team who are good
models of the changed move? Are their clever mental images or
special isolation / exaggeration drills that can help learn how the
changed move should feel "from the inside"? (or how it should not
feel?)
-
Are there special workouts to more quickly develop
some of the skater's muscles in new ways to deliver the
increased power enabled by this changed move? or is it better to
allow the new muscular capacity to develop in the usual way from the
overall training program?
(Other than downhills and maybe fixing some obvious
beginner problems, there is no "free lunch" in skating power. An
increase in power output from a change in technique must be
delivered by an increase in real muscular work -- either from new
muscles getting engaged, or old muscles getting used differently or
used more. Often it takes at least a month for the muscles to
develop the capacity to deliver this work sustainably.)
Video analysis does not improve skating power and speed
because there's nothing in it that forces you to ask those questions --
and nothing in it that tells the answers.
methods for learning
[ more detail to be added ]
I might be making a move in my video which
looks much like the positions and direction and range-of-motion distance
of winning eliter racer -- but the amount of Force I am applying through
that move might be completely different. This difference is critical for
propulsive Work + Power.
It's not that what's in the video image is
incorrect data. But it's captured in a different way how we normally get
visual data through the lense and retina of our eye and the
(unconscious) pre-processing by our brain's super-computer vision
modules.
So sometimes if you try to "see" angles +
lengths in a video image, your built-in visual processing calculations
which are "tuned" for direct eye data will deliver inaccurate judgments.
One problem is that a video image is often sort of "foreshortened": Your
brain assumes that it was shot from a much closer distance that it
really was. Working from that 2-dimensional video image, your brain
performs the amazing task of automatically inferring and "calculating"
angle and length relationships in 3 dimensions. But in this case its
calculations are based on a false assumption about baseline distance.
So when analyzing video for technique, it's
important to select for analysis only the short segment (or individual
frame) that was shot from a camera viewpoint angle that is
appropriate for the specific aspect of motion or position you want
to analyze.
Often the camera viewpoint angle relative the
skater shifts a lot during a video clip, so only a short segment of it
is accurate for analyzing a technique checkpoint - (These pages
sometimes say what angle is best to select for a specific observation).
the image of what the move is supposed to look
like "from the outside" in video does not necessarily help you do it
that way -- because lots of time what it feels like "from the
inside" to make the move is very different. Often it turns out
that different mental images work better for different people to
discover the right feeling. Or sometimes it's not a mental image, it's a
special exercise drill that enables discovery of how to feel the move so
it looks right in video from the outside. Takes experienced and creative
coaching (and a little luck) to find the right combination for each
skater's learning style.
like notice things about the hands and head
and angle of the skate -- instead of the subtle important points, like
stable transmission of force near the hips.
The static positions + angles in a single
frame sometimes feel more "objective". But in the physics usually it's
the motions and accelerations that determine the amount of
propulsive Power + speed. Static position and angles are sort of like
props and scenery for a stage theater production: sometimes necessary to
enable the acting, but never a substitute for the real acting.
progression of learning stages
-
the motions of effective skating for speed are
(objectively) very complicated.
-
often a learning skater needs to first absorb a
simpler style of skating to train their perceptions and timing,
before they are ready to effectively learn to coordinate complex
moves which are optimal for maximum speed.
that's why the approach here includes a "standard-form perceptual check"
style.
-
different skaters are different in what mix of
emphasis on moves + strategies will be fastest for them.
-
different skaters are different in how they learn
(e.g. verbal, video, feeling) and in their progression of skating
stages to learn
-
Priorities: often the aspects of moves and
positions that look most obvious in a video are of secondary
importance for increasing power + speed.
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