September 2016 - Department of Mathematical Sciences

September 2016
Language of Physics Blood Types Remembering Coombs Parks Centennial Skating and Skiing Stress 5-­‐pt Sidecut Skis 1
Page 2
Peak Performance, September 2016
Photo on the Summit
On the cover photo: Doug Coombs takes on the mighty Corbet’s Couloir, often called the “world’s gnarliest marked run.”
Classic photo by Bob Woodall – Focus Productions. See more about Doug Coombs on page 6.
Long time ago, Barry Corbet, a ski instructor at the Jackson Hole Ski Resort in
Wyoming, spotted the narrow ribbon of snow between the rock faces and said “one
day that’s going to be skied…”, with the first descent by patroller Lonnie Ball in
1967. But, I don’t think he said that this will be a marked ski slope.
.
Advice for the first timers going down Corbet’s: stay left, drop, instant hard right, and wrestle back
control before the cliff face on the opposite side is fast upon you.
Jackson Hole’s Aerial Tram will take you up 4,139 vertical feet in 9 minutes.
It can hold up to 100 people plus an operator, and it can operate in 70 mph winds.
2
Peak Performance, September 2016
Page 3
Contents
Page 4
Language of Physics
Juris Vagners
Page 6
Remembering Coombs
Witold Kosmala
Page 8
Parks Centennial
National Parks Foundation
Page 9
Blood Types
American Red Cross
Page 11 Stress – Weight Gain
Witold Kosmala
Page 12 Skating and Skiing
Witold Kosmala
Page 18 5-pt. Sidecut Skis
Witold Kosmala
From the Top
By Witold Kosmala
The Publisher and the Editor of Peak Performance Gazette
PSIA-E Alpine, Level III
Ski Instructor, Coach and Trainer mostly in NC
K2 Ambassador
Welcome all our new and returning readers to this 68th
issue of Peak Performance Gazette. Our passion is
skiing.
This does not mean that every day of our lives we wish
it was winter. It is not just wishing for deep pow
conditions and bluebird skies. It is not just going to
exotic ski areas or attending awesome camps or
clinics. It is not just owning a good pair of skis or
bindings. It is not the love of sliding or a rush it gives
us. The package is much larger than that. If our
passion is skiing we must care about our world, and
about each other, as we are part of it. We must not
only
care
about
physical,
mental,
and
emotional health, but care about so many other things
– practically everything. Try naming one thing that does
not affect skiers, and you will realize that that too is
part of the ski world. We should care even about
where the wax goes off of our boards. Seemingly
everything is part of skiing – definitely not just ski
technique. For this very reason, we try to balance our
Peak Performance publications to include a variety of
topics.
For skiing, LIFE is definitely a must. There is no life
without blood, and there is no synthetic blood. However, so many of us lost blood and needed more of it. The only place
to get more blood (for now) is from another person. I know that without other people donating blood, I would not be here
today. After my skiing accident 8 years ago, I was loosing blood quicker then they could pump more into me, and all that
came from donors. I can’t thank those people enough for giving me LIFE. I wrote an article on donating blood in the March
issue of Peak Performance Gazette. There is another article on blood on page 9 in this publication. I encourage you to
donate. Let’s make a difference in the world one skier at a time.
So, the ski season in the North America is around the corner. Are you prepared? Are you training and studying? Is your
equipment ready to go? Are you motivated and mentally strong? Do you have a plan?
It is good to see you reading this gazette. We hope that you will find it truly worth your while, just
like all the previous issues. Don’t dismiss the old issues. They contain material which is still current.
Hope you can look through the Article Index compiled by Gordon Carr of Sugar Mtn. NC. It can
help you locate an article that you are looking for, or just see what sort of articles have been
published. You can find it the same place where you can find all the issues of Peak Performance
Gazette. Here are a number of ways to do that. Choose your favorite method.
3
Page 4
•
•
•
•
•
•
Peak Performance, September 2016
Use the dropbox www.dropbox.com/sh/wjrz16pzrpho63i/PQr004dmUj
Go to the website www.peakperformancegazette.com
Look up the Facebook www.facebook.com/peakperformancegazette
Google search “Peak Performance Gazette” and see the first item.
Go to the bottom of my Appalachian State University (ASU) webpage www.mathsci.appstate.edu/~wak/
Go to the ASU Library's webpage at www.library.appstate.edu.
My hopes are that these gazettes will serve you as an outstanding reading material no matter what your calling is.
Hopefully these publications will make your skiing passion grow even more, bring you awareness, improve your technique,
take you on the hill more often and help you pass that next certification exam.
Take a minute and write me at
Witold.Kosmala@gmail.com
and tell me what you think about these gazettes. Perhaps you would like to get involved and share your knowledge with
other skiers. Write an article, share a photo, tell us about your unusual or funny experiences, send a donation. I would love
to hear from you.
If you like what you are reading in this and other issues of Peak Performance, would
you be kind enough to tell others about it? Share it with your employees, friends and
family. LIKE us on Facebook. Spread a good word.
For legality issues: The ideas, concepts and opinions expressed in Peak Performance are, as always, intended to be
used in good taste for educational purposes only. The opinions expressed or implied in these publications are not official
positions of the Gazette, unless explicitly noted. Authors and publisher claim no responsibility to any person or entity for
any liability, loss, or damage caused directly or indirectly as a result of the use, application or interpretation of the materials
in these gazettes. Skiing is a dangerous sport. Do it at your own risk. In addition, an advertisement in Peak Performance
does not constitute endorsement by Peak Performance.
Main Course
Language Relevant to Discussions
Of the Physics of Skiing
By Juris Vagners
The purpose of this note is to clarify terminology and definitions related to the physics of skiing. We will review some key
concepts and definitions that often enter technical discussions.
1. Inertia: This is a property of a body defined as the tendency of the body to remain in either a state of rest or in
uniform (rectilinear) motion unless acted on by external, motive force. Inertia is not a force.
2. Momentum: The mass of a body times its velocity p=mv (bold denotes a vector quantity having both a magnitude
and a direction of action). Again, momentum is not a force.
3. Motive forces: Forces originating outside the body capable of changing the momentum of the body, in
accordance with Newton’s Second Law: The time rate of change of momentum is equal to the resultant of all
external, motive forces dp/dt = F. In skiing, the motive forces capable of changing your momentum are a)
4
Peak Performance, September 2016
Page 5
gravity, b) body/ski/snow interactions, c) pole/snow interactions and d) air resistance or drag, unless
you contact an outside object or get help from a friend.
4. To move your CM in any direction, you need a (net) force in that direction. And, if that force is acting on your skis,
it must somehow be transmitted to the body CM. This force may be the result of what you do with your muscles,
but ultimately, these movements must result in a reactive force from your environment, in the case of skiing, the
snow.
5. Newton’s First Law: If F=0 then p=constant. That means if no motive forces are acting you will continue in a
straight line, i.e. your velocity will be in one direction only. This means that once lateral force is removed from the
skis, you move in a straight line.
6. Force: Intuitively, this is a push or a pull.
7. Center of mass (CM): A point in the body where one can place the entire mass of the body to then trace it’s
movement in inertial space according to Newton’s 2nd law. A note here: when thinking about where the CM might
be DO NOT forget the equipment we have on our feet in skiing. Skis, bindings, boots can contribute 25 - 30
pounds to the mass of the skier. This will move the CM of the composite of body plus equipment significantly,
particularly if one starts with a small person (the effect for a 120 lb female is far greater than the effect for a 210 lb
male).
8. Key observation: 1) NONE of the “inertial forces” are motive forces, i.e. cause motion, they are the result
of motion and 2) Since your body sensors are fixed to your body, you DO sense them as “forces”!
Specifically, this is true for centrifugal force, a much used term in skiing. Stop turning and centrifugal
force disappears, turn, and it appears.
So with all this information, how should we think about the physics of skiing? In my mind, the issue is simple: 1) there is
nothing we can do about gravity so let it be and act the way it does, 2) unless one is a downhill racer traveling at
significant speeds, we can neglect air drag, 3) the use of the pole, other than as a timing device or assistance to get to the
lift, is more of a recovery move as opposed to intentional use to help change direction, thus leaving 4) the use (and
misuse) of how the skis and body interact with the snow. Skiing is thus reduced to managing the effects of snow on your
motion.
The usual approach is to think of the action of the snow on the skier in terms of the lateral component or the centripetal
component (centripetal force) as influencing turning and along the ski component (friction) as influencing the speed.
Friction is a useful concept if we are looking at skiing on a groomed surface, in powder, it is not really “friction” but a much
more complex interaction of your skis, boots and legs moving through a resistive medium. Analyzing the physics in this
case is really tough – so rather than try, just go out and get some face shots.
Managing how the ski/snow interaction forces and gravity act on your body then brings us to consider the role of
inclination, angulation and counter. These are the most easily identified things we do with our bodies in creating or dealing
with the ski/snow interaction forces. There are of course quite a number of movements we do in addition that are not
easily observed e.g. what happens inside your boots. However, I think that whatever happens inside your boots is more
“fine tuning” and related to such issues as turn initiation and fine adjustments. In this note, we focus on the larger picture.
A detailed examination of these concepts is a topic for another article.
MEET JURIS:
Education:
BS Aeronautics, University of Washington, 1961
MS Aeronautics and Astronautics, Stanford University, 1963
PhD Aeronautics and Astronautics, Stanford University, 1967
Professional Appointments:
Started at the University of Washington in 1967, went through the professorial ranks, retired 2002 to
Professor Emeritus rank (current).
5
Page 6
Peak Performance, September 2016
Research and teaching activities:
Professor Vagners' teaching interests included dynamics,
classical control systems analysis and synthesis, and optimal
control and estimation. His research interests have been in the
application of unconventional control techniques, i.e., artificial
neural networks, fuzzy logic and evolutionary programming, to
control systems design. Most recently, his research has focused
on autonomous and semi-autonomous Unmanned Aerial Systems
(UAS). In 1998 he collaborated with The Insitu Group on the first
crossing of the North Atlantic by a robotic aircraft. The
Aerosonde Laima , at ten foot wing span and gross take-off
weight of 29 lbs, was not only the first, but by far the smallest
aircraft to accomplish such a historic feat. The crossing took 26
hours and 45 minutes and consumed one and a half gallons of
aviation gasoline. Since then he has been working on various
aspects of cooperative path and mission planning for multiple
UAVs as well as development of quantitative risk assessment
methodology for UAS operations. Another current area of interest
is collaboration between UAVs and Unmanned Ground Vehicles
(UGVs) and Unmanned Surface Vehicles (USVs).
Doug Coombs – a Legend
By Witold Kosmala
PSIA-E Alpine, Level III
Ski Instructor, Coach and Trainer mostly in NC
It is still hard for me to believe that 10 years have gone by last
April, since the death of our beloved legend – Doug Coombs.
On April 3, 2006, at the age of 48, Coombs and three friends
skied down the Polichinelle couloir, a cliff-rimmed run in La
Grave, France. As his group descended the couloir, Chad
VanderHam, a 31-year old aspiring mounting guide, slipped
off
a
490-foot
cliff. As
Doug
peered over the precipice, trying to help his friend, he fell to his death,
as well as Chad. It was Coombs’s love for untamed skiing that
ultimately led to his demise.
Coombs was born in Boston and grew up in Bedford,
Massachusetts, skiing in New Hampshire and Vermont. He attended
Montana State University in Bozeman where he honed his skiing skills
at nearby Bridger Bowl before becoming a fixture of the extreme
skiing scene in Jackson Hole, Wyoming, helping to found Valdez HeliSki Guides (and the heli-skiing industry) in Alaska in 1994, and twice
winning the World Extreme Skiing Championship, in 1991 and 1993.
Photo by Ville Niiranen
To honor Coombs and VanderHam, Per “Pelle” Lang, a longtime
friend of Coombs and owner of The Skiers Lodge in La Grave,
organized a memorial over the weekend on the 10th anniversary of
6
Peak Performance, September 2016
Page 7
Photos by David Reddick
their passing. Above the run where he perished, they placed a plaque that reads: “Master of the Steeps, Pioneer of the
Chugach. He Made it Look Easy.”
Doug Coombs worked with K2 for more than two
years developing a next-generation powder ski,
designed for steep-skiing alpinists and heli skiers. K2
has built an adventure ski and named this ski
Apache Coomba in his honor. The Coomba featured
a tip shape and progressive sidecut that were
predictable and forgiving in powder and variable
snow. Serious alpinists and aspiring backcountry
skiers alike appreciated the Coomba's balanced flex
pattern and 102mm waist width that provided
excellent flotation and easy handling. Later, K2 added
a rocker to Coomba and called it COOMBAck. I have
a pair of those skis. They are indeed awesome. I think
I ski better when I am skiing on Coombacks. They
make me think of Doug, maybe that’s why.
I am on top of Mammoth Mountain holding wonderful K2
Coomback skis.
7
Page 8
Peak Performance, September 2016
National Park Service Centennial
By National Parks Foundation
National Park Service's 100 Year Birthday. August 25, 2016 was the 100th Birthday of
the National Park Service. Starting with Yellowstone in 1872 there are over 400 units in the
National Park Service today.
How Old is the System? The National Park Service was created by an Act of Congress and signed by President
Woodrow Wilson on August 25, 1916. Yellowstone National Park was established by an Act signed by President Ulysses
S. Grant on March 1, 1872, as the Nation's first national park.
The Mission of the National Park Service: The National Park Service preserves
unimpaired the natural and cultural resources and values of the National Park System for
the enjoyment, education, and inspiration of this and future generations. The National
Park Service cooperates with partners to extend the benefits of natural and cultural
resource conservation and outdoor recreation throughout this country and the world.
Who is the director of the National Park Service? Jonathan B. Jarvis
What government agency oversees the National Park Service? The
National Park Service is a bureau of the Department of the Interior. Directly overseeing its
operation is the Department's Assistant Secretary for Fish, Wildlife and Parks.
How many employees are in the National Park Service? Permanent,
temporary, and seasonal: Approximately 22,000 diverse professionals. Volunteers in
Parks: 221,000.
How many areas are in the National Park System? The system includes 413 areas (called units) covering more
than 84 million acres in every state, the District of Columbia, American Samoa, Guam, Puerto Rico, and the Virgin Islands.
These areas include national parks, monuments, battlefields, military parks, historical parks, historic sites, lakeshores,
seashores, recreation areas, scenic rivers and trails, and the White House.
How many people visit the national parks? Total recreation visitors to the national parks in 2015 was
307,247,252.
The most-visited national park is Great
Smoky
Mountains in
North
Carolina
and
Tennessee, with over ten million visitors in 2014,
followed by Arizona's Grand Canyon, with over 4.7
million. The Great Smoky Mountains are a hikers
dream with over 800 miles of tended trails ranging
from short to long strenuous treks. Pictured on the
right is the Sky Lift in Gatlinburg, TN with view of
the Smokies in the background.
The largest national park. Alaska, the largest
state in the Union also has the largest national
park. Actually, seven of the top 10 are located in
Alaska. Wrangell-St. Elias is the largest U.S.
national park with over 13 million acres, far
exceeding the second-largest, Gates of the Arctic,
which covers just under 8.5 million acres.
Rounding out the all-Alaskan top five are Denali,
8
Peak Performance, September 2016
Page 9
Katmai and Lake Clark. Glacier Bay is No. 7 on the list and Kobuk Valley is No. 9.
The largest in the lower 48. The largest U.S. national park outside of Alaska is Death Valley in California and Nevada.
Death Valley is the sixth largest national park. This desert park also has the distinction of having the lowest elevation in
North America at Badwater Basin, a section of the park that is 282 feet below sea level.
Oldest Park. Yellowstone, America's first national park is its eighth-largest. Yellowstone was established in 1872 and
has territory in three states – Montana, Idaho and Wyoming. Along with being one of the largest national parks,
Yellowstone is also one of the most popular. In 2010 the park received 3.6 million visitors, making it the fourth most-visited
national park that year.
The smallest national park site is Thaddeus Kosciuszko National Memorial, at 0.02 acres. The Tadeusz Kościuszko
(Polish spelling) National Memorial is located at 3rd and Pine Streets in Philadelphia, PA. This is the house where wounded
Polish freedom fighter Thaddeus Kosciuszko lived. Hear how this brilliant military engineer designed successful
fortifications during the American Revolution. The house is within walking distance of Independence Hall and the Liberty
Bell Center.
More information. See http://www.nationalparks.org/our-work/celebrating-100-years-service.
Blood Types and Mixing
By Witold Kosmala and
American Red Cross
Blood is the most precious gift that anyone can give to another person — the gift of life. A decision
to donate your blood can save a life, or even several if your blood is separated into its components — red cells, platelets
and plasma — which can be used individually for patients with specific conditions.
LITTLE HISTORY
When a person's blood is analyzed under a microscope distinct blood differences are visible. In the early 20th century, an
Austrian scientist named Karl Landsteiner classified blood according to those differences. Landsteiner observed two
distinct chemical molecules present on the surface of the red blood cells. He labeled one molecule "A" and the other
9
Page 10
Peak Performance, September 2016
molecule "B". The discovery of the blood group system, ABO earned Landsteiner a Nobel Prize. This resulted in 4 blood
types:
•
Blood Type A – If the red blood cell has only "A" molecules (antigens) on it.
•
Blood Type B – If the red blood cell has only "B" molecules on it.
•
Blood Type AB – If the red blood cell has a mixture of both "A" & "B" molecules.
•
Blood Type O – If the red blood cell has neither "A" or "B" molecule. This group was later called "O" after the
German word "ohne", which means "without".
Interestingly enough, in 1910, scientists proved that the red blood cell antigens are inherited.
In addition to the A and B antigens, there is a third antigen called the Rh factor, which can be either present (+) or absent
( - ). Rh factor in blood types stands for "Rhesus Factor". Blood tests were performed on Rhesus monkeys and the Rh+
and Rh- factors were isolated. An antigen found in the red blood cells of most people: those who have Rh factor are said
to be Rh positive (Rh+), while those who do not are Rh negative (Rh-).
THERE ARE 8 BLOOD TYPES
1. O negative. This blood type doesn't have A or B antigens, and it doesn't have Rh factor.
2. O positive. This blood type doesn't have A or B antigens, but it does have Rh factor. O positive blood is one of
the two most common blood types (the other being A positive).
3. A negative. This blood type has A antigens only.
4. A positive. This blood type has A antigens and Rh factor, but not B antigens. Along with O positive, it's one of
the two most common blood types.
5. B negative. This blood type has B antigens only.
6. B positive. This blood type has B antigens and Rh factor, but not A antigens.
7. AB negative. This blood type has A and B antigens, but not Rh factor.
8. AB positive. This blood type has all three types of antigens — A, B, and Rh factor.
Blood banks and hospitals keep careful tabs on blood type to be sure that donated blood matches the blood type of the
person receiving it. Giving someone the wrong blood type can cause serious health problems including death.
WHY BLOOD TYPE MATTERS
The immune system produces proteins known as antibodies that act as protectors if foreign cells enter the
body. Depending on which blood type you have, your immune system will produce antibodies to react against other blood
types.
If a patient is given the wrong blood type, the antibodies immediately set out to destroy the invading cells. This aggressive,
whole-body response can give someone a fever, chills, and low blood pressure. It can even lead vital body systems — like
breathing or kidneys — to fail.
Here's an example of how the blood type-antibody process works. Let's say you have Type A blood. Because your blood
contains the A antigen, it produces B antibodies. If B antigens (found in Type B or AB blood) enter your body, your Type A
immune system gets fired up against them. That means you can only get a transfusion from someone with A or O blood,
not from someone with B or AB blood.
In the same way, if you have the B antigen, your body produces A antibodies. So as a person with Type B blood, you
could get a transfusion from someone with B or O blood, but not A or AB.
Things are a little different for people with Type AB or Type O blood. If you have both A and B antigens on the surface of
your cells (Type AB blood), your body does not need to fight the presence of either. This means that someone with AB
blood can get a transfusion from someone with A, B, AB, or O blood.
0
Peak Performance, September 2016
Page 11
But if you have Type O blood, meaning your red blood cells have neither A or B antigens, your body will have both A and
B antibodies and will therefore feel the need to defend itself against A, B, and AB blood. So a person with O blood can
only get a transfusion with O blood.
Type O-negative blood can be given to people with any blood type. That's because it has none of the antigens that can
set off a reaction. People with this blood type are considered "universal donors" and are in great demand at blood banks.
Because Type AB-positive blood has all the markers, people with this type can receive any blood type. They're called
"universal recipients."
Your Blood Type
A+
O+
B+
AB+
A–
O–
B–
AB–
Donate Blood To
A+, AB+
O+, A+, B+, AB+
B+, AB+
AB+
A+, A–, AB+, AB–
Everyone
B+, B–, AB+, AB–
AB+, AB–
Receive Blood From
A+, A–, O+, O–
O+, O–
B+, B–, O+, O–
Everyone
A–, O–
O–
B–, O–
AB–, A–, B–, O–
American Red Cross Biomedical Services plays a critical role in our nation’s health care system. It is the largest
single supplier of blood and blood products in the United States, collecting and processing approximately 40
percent of the blood supply and distributing it to about 2,600
hospitals and transfusion centers nationwide. The Red Cross also
plays a leading role in protecting the safety of donors and patients
and increasing the availability of blood. It has been among the first
to help develop and implement testing for infectious diseases and is
frequently the single major contributor to clinical trials to improve
blood safety. Providing life-saving blood and blood products to
patients is a key component of the Red Cross mission to help people
in times of emergency and disasters. For more information see
www.redcross.org.
Healthy Turn
Stress – Weight Gain
By Witold Kosmala
PSIA-E Alpine, Level III
Ski Instructor, Coach and Trainer mostly in NC
Stress is a huge idea in the world of skiing and life in general. Stress management is vital in our sport, and it should not be
confused with fear.
In the next few issues of Peak Performance Gazette we will bring up different problems caused by stress. In this issue we
will start with weight gain.
Research shows that levels of "the stress hormone," cortisol, rise during tension-filled times. This can turn our overeating into a
habit. Because increased levels of the hormone also help cause higher insulin levels, our blood sugar drops and one will crave
sugary, fatty foods.
1
Page 12
Peak Performance, September 2016
So instead of a salad or a banana, we’re more likely to reach for cookies or mac and cheese. That’s why they’re called “comfort
foods.”
Jason Perry Block, MD, an assistant professor of population medicine at Harvard, says eating can be a source of solace and
can lower stress. “This happens, in part, because the body releases chemicals in response to food that might have a direct
calming effect.”
Fatty and sugary foods are usually the big culprits, because lots of people have such a strong love for them. The bottom line?
“More stress = more cortisol = higher appetite for junk food = more belly fat,” says Shawn M. Talbott, Ph.D., a nutritional
biochemist.
Drinking water before a meal, eating slowly, eating less and more often may be some ways to keep the pounds off. Not having
comfort foods around the house would be helpful. Can’t eat it if it is not there. Not going to a grocery store hungry is another
way to keep from buying snacks. Or going to a grocery store with only fixed amount of cash. Of course, lowering the stress level
and keeping clear mind would be best.
Here are some tips to ease our stress.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Decrease a workload. Take some time off. Stop to “smell the roses.”
Take a vacation. Go on a road trip.
Go to a waterpark or a beach. Go to kids’ activities.
Go to a relaxing concert. Go to a parade.
Do something that you normally do not do, but be smart about it.
Learn to play a musical instrument.
Do gentle exercise. High-intensity workouts can raise cortisol levels.
Take a brisk walk. Go outside to get “fresh” air. Work in a garden.
Meditate, do yoga or tai-chi.
Get support from family and friends.
Talk out problems with someone.
Read a relaxing book, maybe a love story.
Listen to calming music, soft songs or classical music.
Spend time with pets. Go to a Zoo.
Draw, paint or sculpt.
Get more rest – sleep in particular.
Count your blessings. Pray. Go to church.
Buy something???
Seeing a physician.
GO SKIING!!!
We all struggle with stress once in a while, but you do not want it to be an ongoing thing. Getting it under control is not easy.
Cross-Training
Skating and Skiing
By Witold Kosmala
PSIA-E Alpine, Level III
Ski Instructor, Coach and Trainer mostly in NC
After I am assigned to teach a ski lesson, I try to get acquainted with my students. I will ask them what sorts of activities
they like to do. This often gives me an idea of how quickly they can pick-up skiing, and tells me which spot on a hill to take
them to. If someone tells me that they roller-skate or ice skate – I smile. Inline, quad or ice skaters usually learn basics on
skis quite quickly. Skaters come to a ski lesson with:
2
Peak Performance, September 2016
•
some amount of fitness and athleticism, as well as strong ankles,
•
comfort in sliding,
•
proper basic “home” stance,
•
balancing over balls of their feet,
•
awareness of necessary toe action,
•
loose arms and wrists, and head looking ahead,
•
awareness of the inside edges, especially if they can do leg cross-over when skating,
•
the ability to actually skate as well as to perform step turns.
Page 13
In the next issue of the Peak Performance Gazette, I will discuss all different types of quad skates, for now let me just
mention 3 kinds of skates that we all know of: inline, quad and ice. They all bring different things to the table of skiing.
They are like cousins to skiing.
Inline skates.
Inline skating is often misunderstood for rollerblading. The reason for this is that the company Rollerblade© USA played a
large role in making inline skating popular. Rollerblade© did not invent, design or manufacture the very first inline skates.
But, the company was so successful in marketing inline skates and equipment that the
term "rollerblading" was and still is used when referring to inline skating sports. Inline
skates are often called "rollerblades" regardless of which company actually built them.
The name "rollerblading" has become inline skating to most people, overshadowing
other
manufacturers.
Inline
skating or inline roller skating is the official name for "rollerblading"
or "blading" sports and inline skates is the correct name for
"rollerblades" manufactured by any other company.
It is the same as with a Jacuzzi. A "whirlpool" is the official name
for any spa or hot tub's circular "water action". A "Jacuzzi" is not
a generic name for spas. Jacuzzi is a company that makes
"whirlpool baths" and spas. Any spa or hot tub will provide a
"whirlpool action" of the water.
Inline skates are excellent for simulating skiing at higher speeds.
You can tip them on their side and go around gates, just like skiing.
They are similar to riding a bike at a higher speed where tipping
does more cornering action then actual steering with handlebars.
Wheels are large and not negatively affected by road’s irregularities.
They can be used for long distances and provide great physical
workout. Inline skates are indeed great ski racing training tools.
Quad skates.
Quad skating, often referred to as “traditional,” is absolutely an outstanding cross-training for skiing, especially when
performed at slower speeds and on a slick surface. They can be used outdoors, but wheels are small and all cracks in
sidewalks need to be respected. Stones and other obstacles need to be carefully looked after as well.
You cannot tip the quad skates as much as inline skates, or else outside wheels will come off the ground, so cornering is
slower. Advantages are that in cornering you will need to do more foot steering, like steering when riding a bicycle slowly.
The toe pressure needed to turn the quad skates is the same as in skiing, yet so often over-looked by lower-end skiers.
Instructors often over-look the missing toe articulation in skiers as well because toes are hidden inside the boots and they
don’t see the consequences that are a result of poor foot activity inside the ski boots. In roller-skating these actions are
relatively obvious.
3
Page 14
Peak Performance, September 2016
Any more tipping will make my outside wheels of my
quad skates come off the ground. But, great for low-end
maneuvers and work on fundamentals (like toe
pressures), like riding a tricycle or a bicycle slowly.
Inline skates are like riding a bicycle, good for higher
speeds with less steering and more tipping.
Quad skates have a very short base of support. If your foot
was to be pressured at the ends of their base of support they
would instantly and without mercy jet from under you. You
don’t just tip over – your feet will fly from under you and you
hit the ground before you know it.
If you can inspire quad skaters to skate down a gently tilted
smooth pavement, they will very quickly learn not to move to
the “backseat” at the beginning of a turn as the skates
accelerate.
Same as on other skates, leg cross-over (not recommended
for skiers, unless in a terrain park) teaches valuable inside
edge awareness, even though fore/aft balancing is altered.
Short base of support of the quad skates reminds me of my training on Kneissl’s Big Foot skis
in the 1990’s, pictured above. There is no such thing as sitting back, especially on a steeper
terrain. Skis being short, easily dug into the snow, especially after a jump, resulting in a
possible summersault. The big toes were also not curved up enough and would get caught on
even small snow piles causing possibly unpleasant results. Being short and not really wide
enough, they skied little deeper in the snow then a longer ski would, causing big toe to dig in.
Ice skates.
We all know what ice skates look like and how wonderful they are.
You can tip them, pivot them, steer them – basically anything you
want, they can do it. You can “skate” on them and perform “hockey
stops.” After all, that’s where the name comes from. Absolutely
outstanding tool for cross-training for skiing. But, you have to do it on
ice.
When I was a kid in Poland, my mother would “hose” down a flat area
on the side of our house creating a super rough skating area for my
clip-on a shoe ice skates. Later, I graduated to playing hockey and
developing a never-sit-back or lean forward “home” position.
4
Peak Performance, September 2016
Page 15
Click Link Below to
TM
Request VIPro
Form:
http://www.kneebinding.com/KB-Contact-VIPro.aspx
5
Page 16
Peak Performance, September 2016
In all skating …
It is recommended to wear full body pads (wrist, knees, elbows, bike helmet) and hockey shorts. Pavement or ice is not
the same as snow on an incline! If you have a pad protection you will more likely go out of your comfort zone to improve
your skills. Unless you are like me. I hate to admit it, but I have never invested in any pads. I must be a slow learner. I
never got a road burn from skating, but I did get lots of those from road biking where one never wears leg pads or butt
pads, just crotch pads. But, I did rip muscles in my back when performing a hockey stop on quad skates. I guess I was
just too comfortable on them and forgot what I was doing. Amazingly, I was fine with hopping on skates down the stairs.
From skis to skates
The skill transfer from skis to skates is not as favorable. Low-end skiers have poor “home” position and rely on the skis to
hold them up, as well as excessive skidding. Top end skiers use movements which do not transfer well to skates, like
skillful fore/aft movements. Snowplowing also does not transfer well into skating. Also, skiers will often use poles as their
third point of contact, which might result in a heavy pole drag to improve balancing. There are no poles when skating.
Poor skiers with no toe action will not do well on quad skates. But, skiers of all level can learn skating quickly since much
transfers over. In fact, skating will improve skiers’ performance on the hill.
To come …
There is just as much to skating as it is to skiing. Next few issues of Peak Performance Gazette I will dedicate to sharing
more information pertaining to quad skates. There are many types of skates, many types of wheels, many types of
bearings and bushings, some will give you a rebound and others will not.
6
Peak Performance, September 2016
Page 17
Turn to Wisdom
•
What you get by achieving your goals is not as important as what you become by achieving your goals.
•
Remember that happiness is a way of travel, not a destination.
•
Some people dream of success, while others wake up and work hard at it.
•
The need is constant, the gratification is instant. Give blood!!!
Deep Stuff
What are you hungry for in life, and why?
Thoughts for the Month
•
What is “side-country” skiing?
•
Is the center of mass and center of gravity one and the same?
•
Name some different types of quad skates.
•
What is meant by the “knee angulation?”
Elaborations on last month’s Thoughts for the Month.
Question. (From April 2016 issue.) What makes one blood type different from another? Can they be mixed?
Answer. See article on page 9.
Question. Since steering movements are to start with your feet, why do coaches correct arms, head, back, and all
sorts of other things first?
Answer. If the key body parts are far from being in the right place, there is no way feet can do what they are supposed
to do.
Question. Is it easier to turn the skis when your feet are really close together or when your feet are about 6 – 8 inches
apart?
Answer. 6 – 8 inches apart.
Question. Why do ladies swing their hips when walking more likely then men?
Answer. On the average, ladies are looser and more flexible in their hips then men. Because of that, hips move around
more when walking. It actually takes more work for ladies to keep their hips in a straight line when walking, so why work
so hard? Just let them swing. But, then skiing creates yet another challenge for the ladies that unnecessarily swing their
hips because that swing over-rotates the body when turning.
Question. What are 5-pt sidecut skis?
Answer. See article on page 18.
7
Page 18
Peak Performance, September 2016
Turn Here and There
5-pt SIDECUT SKIS.
A ski of traditional profile is widest at the tip, narrow underfoot
and wide again at the tail. The so-called, 5-pt sidecut skis
have their widest points closer to the binding so the shape
tapers towards the tip and tail. Benefits are:
•
greater maneuverability, especially in deep snow with
plenty of surface underfoot
•
skis feel short and are easy to swing from side to side,
but still provide fore/aft support and ability to guide
the turn entry and exit
•
skis feel light and narrow at the tips and don’t get
hooked up as easily
•
they are like skis with reverse camber in powder, but
with enough camber under foot to allow carving on
the groomers.
Rossignol Sky 7 HD Skis 2017
The Bottom Line
Peak Performance depends on its sponsors. If you find these publications worthwhile, I hope you will choose to support
them. Every little bit helps. Sponsors of this issue of Peak Performance are:
•
•
•
•
•
•
KneeBinding Company
K2 Ski Company
French Broad River Academy, Asheville, NC.
Eastern Division of the Professional Ski Instructors of America.
Chris Anthony Youth Initiative Project, Vail, CO
Anonymous individuals
Base of Support
I invite you to support this gazette. You can do this by one or more of the following:
•
•
•
•
•
•
Send a monetary donation to Witold Kosmala, Department of Mathematics, Appalachian State University, Boone,
NC 28608, USA.
Sponsor the gazette and in return we will publish your ad for a month, several months, or a year.
Submit an article or a photo for publication.
Share Peak Performance with your friends.
Like us up on Facebook.
Send comments and suggestions to me at Witold.Kosmala@gmail.com.