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U.S. Pat #6871608
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M
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Re-edited
02/2008
Biomechanical and Ergonomic Solutions in Kayaks
1. The Problem
Ergonomics
is a science also known as Human Factors Engineering.
The
problem is simple, and sooner or later practically any kayaker and
kayak fisherman
faces it: Spending long hours paddling and fishing in or on top of an
ordinary kayak (sit-in or sit-on-top) inevitably causes some
circulation problems and leg
numbness, occasional cramps, pain in your lower back, and often fatigue
and discomfort
in
your shoulders and neck.
In fact, kayaking is so closely associated with back pain that kayakers
commonly appear in TV ads for back pain relief patches and drugs...
After you begin seeking information about your problem and advice on
ways to solve it you realize that the only thing
that really works is paddling back to shore, standing up and performing
the exercises that physiotherapists recommend for kayakers. In
other words, there is no gear that you can outfit your ordinary kayak
with that can provide an effective and long lasting solution to any of
these symptoms simply because they occur as a result of you being
seated in the L position - the traditional sitting position in kayaks.
2. The Root of the Problem - Being Seated In The Traditional, L
Kayaking Position
The problem is caused by a combination of two things:
1. Being seated in a non ergonomic position to start with,
and
2. Being unable able to switch to any other position and
release the stress that builds up in the critical pressure points in
your body, especially in your legs and lower back.
Have you ever asked yourself why
is it that the traditional, L kayaking
position is used only in ordinary kayaks and in no other land, snow or
water equipment? The answer is that it's because although the L
position is the worst for you it's simply the only one that ordinary
kayaks can offer.
Double Trouble: The
Combined Effect of Horizontal and Vertical Pressure on Your Lower Back:
Figure
1. Horizontal Pressure
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Figure 1 on the
left shows
the horizontal pressure that
your legs exert on your lower back in the traditional L position used
in all ordinary kayaks including both
sit-in (SIK) and sit-on-top (SOT).
The pressure points in the lower back
region can cause irritation and inflammation of the sciatic nerve
(sciatica) felt as pain traveling from the lower region of your back
down across your lower thigh.
Foot braces and other support for your feet actually increase the
horizontal pressure that your legs exert on your lower back.
The
back support and foot braces may hold you in your
torso in place and prevent you from falling backwards or slipping
downward, but
they also limit your freedom of movement, increase pressure on your
lower back, cause leg numbness and cramps and result in increased
fatigue.
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Native people of
the Arctic circle who were the first to
make and paddle kayaks used
neither back rests nor foot braces simply because they were accustomed since
infancy to
sitting on the floor
with their legs stretched forward, unlike us modern Westerners who lose
this ability in early childhood when we learn to sit on chairs.
Figure
2. Vertical Pressure (Weight)
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Figure 2 on the
left shows
the heavy vertical pressure
(weight) applied on the lower
part of your spine when you're seated in the traditional L kayaking
position.
The
same sensitive area in your spine that's pressurized horizontally by
your legs pushing on it is being pressurized even more by the combined
weight of your torso and thighs, that is nearly all your body
weight.
Your legs are prevented from supporting your body weight in this
position.
In
addition, sitting in the L position without being able to change your
body position increases your fatigue and discomfort, and reduces both
performance and fun.
Cushioning your seat doesn't really solve any of these problems since
all it can do is spread the pressure from a single point to a wider
area, but the combined pressure is still there and it keeps working on
your lower back all the time. Sooner or later you feel very
uncomfortable, and sometime it's too late since you've already been
injured.
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Kayaking
in the L position with no adequate support for either back or feet is
not a sensible solution for modern anglers and paddlers who have to
spend hours
kayaking and fishing from this low and uncomfortable position.
Food for thought:
If you had to perform some hard work or other physical
activity in any position of your choice, would you even consider doing
it sitting with your legs stretched forward like this?
Do you
fish or do you know anybody who fishes seated in this position from
shore or from any other type of fishing boat? -The
answer is: ABSOLUTELY NOT!
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More food for thought:
Airplane coach seats are fairly comfortable - certainly more than
regular kayak seats, but why is it that after some
time most people feel uneasy sitting in them? The answer is
that the limited space makes it difficult for you to change positions,
which
leads to the buildup of discomfort and fatigue to a point where many
people feel they must stand up and stretch, and those who can afford it
promise
themselves to fly first class next time - if only for the extra legroom. |
Long term effects
Not all damages are felt immediately.
Sometimes it takes years for the damage to accumulate, and by then it
might be too late to fix it. This is true for back and shoulder
problems.
Read more about kayaking
back pains and leg numbness
3.
Search in the Right Direction
What
do cross-country motorbikes, mountain bikes, horses, snowmobiles,
all-terrain vehicles (ATV) and personal watercrafts (PWC) have in
common? It's the Riding
Position.
And what do skiing, surfing, water skiing, dog sledding, snowboarding,
windsurfing, skating and skateboarding have in common? -The Standing Position.
It's
simply because the Riding and Standing positions are the best for you
in both ergonomic and biomechanical terms, which means they offer best
control and more power, and result in less fatigue and injuries.
When we need to
make long efforts during motion we have more
available power and better control standing or sitting with our legs
lower than our upper body (biomechanical advantage),
and we also feel more comfortable and less tired this way (ergonomic advantage).
4.
Engineering the Optimal Solution
For
a solution to be optimal fro you it should first
offer
you the best support to your physical effort to begin with, and in the
case of fishing from kayaks it means maximal lateral stability. Then it
must enable you to both paddle and fish in the most ergonomically
advantageous positions, and give you the ability to switch between
these positions anytime, which is exactly what the patented W Fishing
Kayak offers you.
Freedom to Choose = Less Fatigue = Enhanced Comfort = More Fun and
Healthier Paddling and Fishing
Only the W solution departs
radically from the L
position and offers a new, comprehensive and effective approach to
all ergonomic and biomechanical issues.
The new,
patented W Kayak re-distributes buoyancy from the boat's longitudinal
axis to its two sides and thus offers maximal support to the
kayak fisherman's balancing, control, steering, propulsion and fishing
efforts.
The central part
of the W Kayak- it's 'backbone', which joins the two hulls has the
shape of a long, 14" high saddle. The W Kayaker can move
back and forth on the saddle according to his/her need (e.g. surfing,
taking out etc.) and he can also switch anytime between four ergonomic
kayaking positions:
1.
Riding (Mounted)
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The Natural Position:
Riding is the most stable position, and it
offers you best control over your boat as well as excellent leverage on
your paddle.
In
the Riding position your thighs, legs and feet are positioned directly
below
your body and take active part in all your efforts: Balancing, Control
and Paddling.
Riding
is the best
position for beginning W Kayakers. It is also
the best position in whitewater and surfing applications.
Fishing:
This is the preferred position, second only to standing. When casting
in the Riding position you have both more power and more height than
sitting.
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Riding Position: Legs on Both Sides of
the Body
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Riding (mounting) the W saddle
Riding a W Kayak is similar to mounting a
pony:
Your
upper body rests on the saddle, your thighs hold its sides, and
your feet rest firmly at the bottom of a hull, as they would in
stirrups. |
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2. Sitting
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Sitting means having
your legs positioned in front of your body. Sitting is less stable and
powerful than Riding, and not recommended
for beginning W Kayakers, or for moving water.
Adding a back rest (lumbar support) is not necessary but stadium seats,
kayak seats and even plastic chairs can be easily fitted inside the
cockpit.
Variations:
1. Regular sitting, which is similar to
sitting in a canoe
2. Sitting with both legs stretched forward
3. Mixed: one leg in the regular position and
the other stretched forward
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Sitting
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Regular
Sitting - Legs Stretched forward |
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Regular
Sitting Position
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Sitting
With Legs Stretched Forward
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3. Kneeling
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A very powerful paddling position, which is
preferred by racing and whitewater canoeists.
In your W kayak the kneeling positions
are good for racing and for paddling against
strong wind and current. You can kneel on one knee ('High
Kneel') or on
both knees. You may use either a
double blade or
single blade paddle.
If your knees don't reach the bottom of the hulls you can use
padding as seen in the right side image
Fishing: While Kneeling doesn't
offer any particular advantage when casting using the 'High
Kneel'
can make a difference when you're struggling with a strong fish and you
need extra power.
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"High Kneel"- on one leg
Kneeling on both legs
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4.
Standing
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Standup paddling is easier than it looks
-You can paddle standing with your legs parallel or in
diagonal, and with the knees either straight or bent (similar to
skiing).
You can paddle on both sides of the boat or just on one side- in
parallel and with a J stroke.
After some practicing you could try to paddle standing in moving water
and in the surf.
In such conditions it's recommended to have your feet pointing a little
sideways for additional stability.
Fishing:
Standing is the natural, preferred position that offers both leverage
and height. If you find it hard to fight a strong fish and balance
the boat you can switch to a lower position - preferably Riding.
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Kayak skiing - one
side Kayak skiing
- both sides
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NOTE: Taller,
heavier and older people are generally more challenged in paddling, and
therefore in paddling standing too.
Height, weight and age should be considered as factors that might slow
your learning of paddling standing.
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5.
Side Saddle
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You can sit in this new position only in
the 2008 models, that have a lower spray deflector.
Side Saddle is
practical as a static fishing position in shallow water.
It can offer sufficient space, comfort and stability for two adult
fishermen to use a 2008 kayak for fishing together, which is difficult
if both were to sit inside the cockpit.
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Other
Positions
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More
Options |
The W design enables additional positions:
1. Mixed
Riding and Sitting:
You can paddle and fish with one leg in the Riding position and the
other leg
placed forward in the regular sitting position, or completely stretched
forward.
Such position can be useful for counteracting a lateral current or
wind, and simply as one more option for reducing fatigue in long trips.
2. Sitting with one leg folded on top
of the saddle:
This position can be comfortable when you spend time in one place and
need to operate a fishing rod or a camera.
It is also useful when two people paddle in tandem using single blade
(canoe) paddle - each on a different side of the boat.
3. Sitting
with both legs in one hull:
Since this position is not particularly efficient for paddling it can
be useful mainly when the boat is static and occupied by two people,
each facing a different side of the boat, e.g. when fishing, bird
watching or photographing.
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Putting a plastic armchair in the
cockpit may not be a very efficient solution for either paddling
or fishing, but it's a most relaxing one on flat water...
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Key To Best Stability |
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The patented W
Kayak offers improved stability by combining three things:
- Distribution of
the boat's buoyancy along its sides instead of along its central,
longitudinal axis.
- The
users and passengers make natural use of their legs and feet to balance
themselves by shifting their weight from one leg to another, and
they apply this weight directly at the bottom of the hulls -below
waterline, thus creating an effect of 'dynamic ballast'.
- By
offering a high level of lateral resistance the immersed profile of the
W hulls acts as 'Hard Chines' do in traditional, monohull kayaks and
canoes.
The figure on the right shows a cross section
of the W Kayak hulls at 200 lb load.
More info on stability
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Cross Section of W Fishing Kayak |
5. Casting
The
W Kayak offers you the ability to throw to longer distances, which
presents two advantages:
1. Being able to cover more water from a stationary
position before you need to move your kayak
2. Some fish species can sense the presence of your kayak nearby and therefore are better caught
from a distance.
For more information visit our website's Shallow
Water Fishing section
6. The Cockpit - A better place to be in and work in
The
cockpit has other functions besides protecting you and offering you
optimal comfort:
It is also a workplace in which you store and handle different tools
and equipment.
Inside
the cockpit (photo: Jeff MG, FL)
The saddle's top side ('mini-deck') provides a comfortable working
platform
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The photo on the left may offer a certain idea of what it's like to sit
on the saddle and handle fish and fishing gear.
All the gear you need is within arm's reach yet there's no chance of it
going overboard since in case it slips out of your hand it usually ends
at the bottom of one of the hulls, where it's easy for you to find and
reach it.
A partial view of 6'4" Jeff stretching his legs in the cockpit of his W
Fishing Kayak
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Paddler Size and Additional Considerations
This information is taken from our
Kayaks Product Info page
General Limitations
Exceptionally
tall and/or very heavy people, and/or
people with certain physical disabilities can find it more difficult to
paddle traditional canoes and kayaks.
Similarly, such people might experience
some difficulties in W Kayaking that most people won't
experience.
This is especially true for people with severely
injured or disabled knees because of the important role the legs have
in all W Kayaking positions.
W Kayak Data
The following tables are offered in order to help
you evaluate the likelihood of the W Kayak being appropriate for you
and for the applications you are planning for it. The numbers are
not absolute and represent our best estimate based on on
experience. If you have questions regarding these or other issues
please CONTACT US
You may find this information useful is understanding and assessing the
likelihood of other kayaks and canoes being fit for you and your needs.
Other factors play
significant roles in the overall quality of W kayakers'
experience. Such factors can be:
NEGATIVE: Older age, Lack of experience in Canoeing, Balance problems,
Knee problems, Gender (Male)*
POSITIVE: Younger age, Previous experience in Canoeing, Good balance,
Good physical condition, Gender (Female)*
* Note: Generally, men's Center of Gravity (CG) is higher than that of
women of similar height.
I. Estimates for Your
Height and Weight As Factors in Your W Kayaking Experience
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OK
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OK
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No
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No
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OK
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OK
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OK
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No
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OK
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OK
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OK
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OK
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OK
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OK
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OK
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OK
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OK
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II.
Recommendations For Types of Load and Total Loads As Function of Number
of Passengers, Passenger Physical Attributes, Gear Weight and Paddling
Environment
A
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B
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C
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D
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E
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F
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G
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Total
Number
of Passengers
on Board
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Maximum
Recommended
Weight of Heaviest
Passenger on Board
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Maximum
Recommended
Height of Tallest Passenger on Board
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Total
Maximum
Recommended
Combined Weight
of All Passengers
on Board
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Total
Maximum
Gear Weight Recommended
With Maximum
Recommended
Combined Weight of All
Passengers (D)
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Total
Maximum Recommended Weight on Board - Passengers Plus Gear (DE) for
Flatwater
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Total
Maximum Recommended Weight on Board - Passengers Plus Gear (D+E) for
Moving Water
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1
Passenger
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240
lb (113 kg)
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6'
6" (198 cm)
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240
lb (113 kg) |
70
lb (32 kg)
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310
lb (145 kg)
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280
lb (127 kg)
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| 2
Passengers |
220
lb (109 kg)
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6'
4" (193 cm)
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270
lb (122 kg) |
50
lb (23 kg)
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320
lb (145 kg)
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280
lb (127 kg)
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| 3
Passengers |
200
lb (91 kg)
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6'
2" (188 cm)
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290
lb (132 kg)
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20
lb (91 kg)
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310
lb (141 kg)
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280
lb (127 kg)
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**Note: It is assumed
that the passengers are generally fit to paddle canoes and kayaks, that
heavy gear is stored mostly in the bottom of the hulls, and that water
and weather conditions are not extreme i.e. storms, whitewater, heavy
surf etc.
If you have questions regarding these or other
issues please CONTACT US
W Kayak - Draft As Function of Load:
Note: This figure shows the boat's draft and freeboard as function of
load, but one has to be aware that a small boat such as a canoe, kayak
or W kayak reacts very differently when loaded with gear than it does
when loaded with passengers, especially if the heavy gear is stored at
the bottom of the hulls - below waterline.
When the boat is heavily loaded it is recommended to paddle it in the Riding
position, which offers the highest degree of stability and control, and
a biomechanical advantage in paddling (see above paragraphs)
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M
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