Fin Propulsion and Force Fin’s Efficient Kick

Populsive Divers Kick, Efficient Kick

Divers propel themselves by moving their legs (and the increased surface area of their fins) back and forth against the water with a flutter kick motion. This kicking results in a complex combination of propulsive forces that move the diver forward as well as resistance or drag forces that hinder that movement.

With other fins, virtually all of the propulsion comes from the downward phase of the kick (imagine you’re horizontal in the water with your stomach toward the bottom) and almost none on the up-kick. You can test this yourself in the water by trying to kick up, with or without fins. You’ll go nowhere. But simply extend the lower leg down and watch yourself move ahead.

Force Fin KickOne reason for this uneven propulsion is that humans naturally have more strength when kicking down. The power or downward phase of the kick emphasizes the powerful quadriceps muscle group at the front and side of the upper leg. The kick’s upward phase uses the weaker hamstrings at the back of the thigh and is mainly a recovery movement setting up the leg for the next power phase. The result is a natural two-stroke kicking cycle of power and recovery for each leg. It’s the same with other continuous activities like running, bicycling or swimming where a power/recovery cycle is built-in to conserve your energy.

While most other fins make you work just as hard on the recovery as on the power phase, Force Fins take advantage of this two-stroke cycle and work in harmony with the body’s natural strength. The flexible blade of our Force Fin opens out to its maximum surface area to move a high volume of water during the powerful downward portion of the kick.

During the recovery, the blade folds down, channeling water behind while limiting resistance to conserve your energy. (If you have to put the same amount of energy into both parts of the kick, you fatigue much sooner.)

As you kick down, the blade opens out to its maximum surface area, engaging the muscles of the whole leg to push water and provide initial forward thrust.

 

At the end of the downstroke, the fin recoils, setting up to rebound to its original position during the recovery or return kick stroke.

 

The fin then rebounds to help begin the upward recovery phase of the two-cycle kick stroke.

 

The fin’s tips fold inward to aid the upward recovery and to prepare your leg for the next downward power stroke.

 

Force Fins are the only fins that provide propulsion consistent with your natural two-stroke kick cycle to this degree. By providing for more of a separate power and recovery phase, oxygen depletion is reduced, and the onset of fatigue is delayed. The result is that divers can kick continuously for longer periods of time.

SCUBA FINS

Powerful Fins, Are They the Best Fins?

ARE “POWERFUL” FINS REALLY BETTER?

powerful fins, navy diverOne of the biggest areas of confusion regarding fins is the notion of “power.” Many divers believe that the more they can feel their fins, the more they’re getting out of them. And to capitalize on this belief, many fin manufacturers have responded by making longer and stiffer (more “powerful”) fins that fool divers into thinking that they are generating more propulsion with less effort.

However, the laws of physics don’t agree.

You are the power for your forward movement, the more you can feel your fins, the more energy you’re expending and the more you’re working for them, instead of having your fins work for you

“Power” is a measure of energy expenditure. More power requires more energy, and more energy requires more effort, not less. A 100-watt light bulb is more powerful than a 60-watt bulb. It puts out more light, but it also uses more electricity and costs more to operate.

The same with fins. What divers believe to be power in fins is really resistance. That’s what you feel. “Powerful” fins rapidly waste your energy supplies and actually transfer a much smaller percentage of the effort into forward propulsion than you think.

Since the name of the game in diving is to decrease energy use (which decreases oxygen consumption and increases bottom time), it makes sense to use more efficient fins, not more “powerful” ones, as long as they do the job of moving you through the water.

The fact is, no fins have power. You are the power for your forward movement, the more you can feel your fins, the more energy you’re expending and the more you’re working for them, instead of having your fins work for you. Force Fins are specifically designed not to be felt; Force Fins are designed to work efficiently for you.Extra Force Fin, Powerful Fin

And, for those of you who still want “power” our EXTRA FORCE FIN is the best fin.

The Extra Force Fin has the largest surface area for extra leverage under load. The way Master Fin Designer Bob Evans puts it, “You don’t fly a learjet to carry a herd of elephants. You fly a 747 or C130. The EXTRA FORCE FIN is our C130.

 

EXTRA FORCE FIN

No Pain, No Suffering, Fins Without Cramps

tan delta force fin

Pain & Suffering a Thing of the Past

One of the most common complaints that people have about diving is that their feet and legs hurt when they try to kick with today’s long or stiff fins. Their arches or calves cramp, their toes are smashed into the end of the foot pocket, their legs tire… Sound familiar?

The primary cause of all this pain is that most fins are designed to concentrate much of the force from kicking on the smaller muscles of the lower leg and feet. And those muscles simply can’t take the stress of powering a large fin blade through the water. The result? Fatigue and cramping.

But with the trail-blazing Force Fin, our unique foot-pocket design transfers much of the effort of moving the blade to the largest muscle group in your body, the quadriceps, removing pressure from the toes and feet. Because your entire leg is now doing the work, muscle fatigue and cramping is significantly reduced.

Force Fins are designed to let your toes really breathe, move and wiggle about like they’re meant to do. Because of our true, open foot pocket, your toes are finally free!

Try this simple test to see the difference between how our fins work with your body as compared to other brands.

While seated, cross your ankle over your knee, grab your toes and pull them in the direction of the sole of your foot. Do you feel the stretch and tension running from the top of your foot up and along the shin? Those are the primary muscles that other fins work because the fin blade extends from your toes.

Now, hold the top of the foot – pull again toward the sole of the foot and resist with the leg. The tension has moved up to the upper leg, hasn’t it?

Because of their unique design based on human bio-mechanics, Force Fins work the larger muscles of the upper leg in addition to the lower leg. These muscle groups are large and powerful. They are best equipped to efficiently power your fin blade.

DIVE FINS     SWIM FINS

The Truth About Swim Fins

Force Fin Swim Sponsor

WHY SWIM WITH FINS?

Increase fitness and cardiovascular conditioning
Increase ankle flexibility
Develop leg and swim kick strength
Improve body position and technique so you can swim fast

WHY SWIM WITH FORCE FINS?

Foot-Pocket Design that leverages power from your strongest kicking muscles in the upper thigh
Snappy Blade Design promotes high turnover, with power and recovery for aerobic workout
How Force Fins are made, hand crafted in the USA using highest quality polyurethane

WHY FORCE FIN SWIM FINS?

We’ve been designing and making improvements to fins for over 30 years, with millions of satisfied customers, and many major product design awards under our belts, we can honestly say that we are the experts in fin design. That’s all we do, and we think our innovative fins are without equal in terms of comfort, efficiency, durability, performance, versatility and sheer value for your money.

We offer a variety of fins and each as been developed in response to your needs, comments and suggestions. Studying marine animal locomotion and human biomechanics, we have researched and designed our fins to take advantage of the laws of nature and physics. Not to mention common sense.

Open Toe Pocket Design

Slim Fin fins for swimming

 

Unlike all other fins, even those with open toe boxes, only FORCE FIN swimming fins are designed to concentrate the force of the blade further back on the foot, using the muscles of the whole leg, not just the lower leg.

Your toes are free to wiggle about to feel the water.


Patented Blade Design

Force Fins fins do not have flat blades like most other brands. Instead the blade curves up or away from the bottom of your foot to provide more resistance on the power or downward (during freestyle) phase of the kick. The blade then snaps back to assist on the recovery. This two-stroke cycle does several things for a swimmer:

By kicking against a load that provides for a separate power and recovery cycle as opposed to the traditional power-power cycle of other fins, oxygen depletion is reduced, the legs and body work more aerobically and less anaerobically, and swimmers can maintain their workout efforts for longer periods of time.

Independent research has shown less lactic acid buildup (lactic acid is the proof of anaerobic activity) and more oxygen absorption with Force Fins. Flat fins, other fins bring on symptoms of fatigue and cramping more quickly.

Other fins, flat fins want to go through the water along the path of least resistance, which is sideways! Don’t believe it? Hold a flat, heavy object at the surface of the water, let go and watch what happens. It turns on its edge and heads for the bottom. Or, if it’s light like a sheet of paper, it will zig-zag or “dish” its way down. Neither action is going to help your kicking. With flat fins – even small or cutoff flat fins – a swimmer is constantly fighting all this twisting and torquing, and any effort spent this way is wasted.

FORCE FINS or SLIM FINS?

Force Fins are our original design, and being somewhat larger than Slim Fins, they provide a more concentrated leg workout (more resistance). They are a more versatile fin, in that they can be used for other sports, such as snorkeling, SCUBA and float tube fishing. From a swimming perspective, they are a very specific training tool and are excellent for butterfly, “new-wave” breaststroke, and the backstroke dolphin kick.

Slim Fins are narrower than the Force Fin and are specifically designed for pool swimming – especially freestyle – applications. With Slim Fins, the blades don’t touch, flip turns are no problem, and high stroke turnover or cadence is easily maintained. Slim Fins can be used either while swimming or in kicking-only drills. They receive the highest recommendations from swimming coaches and professionals, and will do the best job for and are probably the best choice for most swimmers.

HOW ARE THEY MADE?

Manufactured in the USA and backed by more than 30 years of research and development, Force Fin swimming fins are made of ultraviolet-, abrasion- and chemical-resistant polyurethane and heat-treated for 16 hours at temperatures where other fins melt. This process allows the molecules to cross-link giving the blade its snappy, high-performance characteristics and extreme durability. Unlike other brands, Force Fin swimming fins will not melt on hot pool decks or mark the sides of pools, and should last season after season, even when used daily.

We could go on forever describing the unique benefits of using Force Fin swimming fins to improve your swimming. But there’s only one way to really find out why our fins are the best swimming fins in the world: try a pair you will be happy!

SWIM FINS

Body Position and Swim Technique

swim position, swim technique

Improve Body Position and Swimming Technique

Fins add extra propulsion to the stroke, which increases a swimmer’s speed through the water. Good swimmers tend to plane on top of the water while poor swimmers tend to drag their legs and swim in a more vertical position slowing them down.

One of the goals of swimming faster with fins is to swim faster when the fins are taken off! By transferring the feeling of swimming faster and higher with fins to swimming without them, a swimmer makes use of a phenomenon know as neuromuscular patterning. The muscles and the nerves can actually remember the feeling of swimming faster and will try to duplicate the pattern the next time out. The more times the pattern is repeated (swimming faster and higher in the water with fins), the easier it is to duplicate it. The end result: the swimmer’s technique and neuromuscular coordination improves.

“The curves and flexibility of our blade design help keep the legs properly oriented for more efficient power, even as they fatigue.

Force Fin swimming fins utilize the body’s strength and put it where it’s needed. The human body is built to have more strength when kicking down (during freestyle), than when kicking up. The downward or power phase of the kick emphasizes the powerful quadriceps muscle group at the front and side of the upper leg.

The upward, recovery phase uses the weaker hamstrings at the back of the thigh. While still developing both sets of muscles, our blade design assists — or helps take the load off — the upward recovery phase that uses the weaker muscles, maximizing energy efficiency. Flat fins, other fins make your legs work as hard on the recovery as on the power phase of the cycle, because the flat rigid fins must push aside water to get back into position.

As you kick down, the blade pushes against the water engaging muscles of the whole leg and providing initial forward thrust.

At the end of the downstroke, the fin recoils, setting up to rebound to its original position during the recovery or return kick stroke.

The fin then rebounds to help begin the upward recovery phase of the two-cycle kick stroke.

The fin’s tips fold inward to aid the upward recovery and to prepare your leg for the next downward power stroke.

  • The snap of the blade helps increase kicking tempo keeping correct arms-to-legs coordination intact. There’s no worry about the kick slowing down unnaturally as with all other fins.
  • The rebound of the blade during the recovery phase helps bring the legs higher in the water (during free-style), raising the lower body to the surface in the desirable high-in-the-water position, where you encounter less drag and can swim faster and more efficiently.
  • Other fins, flat fins want to go through the water along the path of least resistance, which is sideways! Don’t believe it? Hold a flat, heavy object at the surface of the water, let go and watch what happens. It turns on its edge and heads for the bottom. Or, if it’s light like a sheet of paper, it will zig-zag or “dish” its way down. Neither action is going to help your kicking. With flat fins – even small or cutoff flat fins – a swimmer is constantly fighting all this twisting and torquing, and any effort spent this way is wasted.The curves and flexibility of Force Fin  blade design help keep the legs properly oriented for more efficient power, even as they tire.

SWIM FINS

Develop Leg Strength by Kicking Fins

kicking with swim fins, slim fins

How To’s  of a Good Swim Kick

Kicking with fins is like lifting weights: the added resistance of the water on the blade of the fin increases the workload on your leg muscles. Your body adapts by increasing the strength and endurance of the muscles involved. Stronger muscles move more water making you swim faster, all other things being equal.

Force Fin,Kicking with FinsA word about specificity: It’s important to realize that muscular strength for swimming needs to be “specific.” Good runners, cyclists, roller bladers, etc. can have very strong leg muscles, but the muscles have developed for running, cycling or roller blading, not for swimming. Fins develop leg strength specifically for swimming, and in a way that few other activities can.

“Force Fin swimming fins utilize the body’s strength and put it where it’s needed. The human body is built to have more strength when kicking down (during freestyle), than when kicking up. The downward or power phase of the kick emphasizes the powerful quadriceps muscle group at the front and side of the upper leg. The upward, recovery phase uses the weaker hamstrings at the back of the thigh. While still developing both sets of muscles, our blade design assists — or helps take the load off — the upward recovery phase that uses the weaker muscles, maximizing energy efficiency.”

SWIM FINS

Flexible Ankles to Swim Better and Swim Faster

swimming, kicking with fins, slim fin

Increase Ankle Flexibility

Have you ever noticed that runners, cyclists or triathletes new to swimming who start a serious swim program have a hard time just kicking and going anywhere? In fact, they sometimes go backward! One reason is that their ankles are so inflexible that when they kick, their feet act like hooks, catching the water and pulling the frustrated swimmer in the wrong direction.

Good swimmers, on the other hand, can hyper-extend (plantar flex) their ankles, pointing their toes so that the top of the foot forms a straight line with the shin. Because of the extra load from the increased surface area that fins provide, swimming or kicking with fins forces ankle extension during the power phase (pushing down when swimming freestyle) of the kick. Repeated fin use eventually stretches the ankles, increasing their flexibility for moving in all directions and helping the kick become more propulsive and efficient.

The extra load from the increased surface area that fins provide, swimming or kicking with fins forces ankle extension during the power phase (pushing down when swimming freestyle) of the kick. Repeated fin use eventually stretches the ankles, increasing their flexibility for moving in all directions and helping the kick become more propulsive and efficient.

Ankle flexibility is one key to efficient kicking.

flexible ankles,ankle flexibility, swimmingTo measure your flexibility, sit on the floor with legs extended and place a stiff piece of paper against the side of the foot. With heels touching the floor, point your toes as far forward as you can while having someone trace this side view.

Measure the distance from the base of your big toe to the ground or floor; your goal should be from one to four inches.

Using a regular program of kicking with FORCE FIN swimming fins, re-measure and chart your progress.

SWIM FINS

Increase Fitness and Cardiovascular Conditioning

Slim Fin

Only Force Fin swimming fins are designed to concentrate the force of the blade further back on the foot, using the muscles of the whole leg, not just the lower leg.

 

Although swimming is considered one of the best aerobic or cardiovascular-conditioning exercises, many people forget to use their legs where the largest muscles are located. Since the greatest cardiovascular benefits come from including the highest percentage of the body’s muscles – that’s why cross-country skiing and rowing are considered two of the most demanding sports – it makes sense that swimmers who activate the large muscle mass of the legs by kicking will benefit from a more demanding workout that burns more calories and increases fitness levels.

Add fins to the equation and the increased load they add to the legs means that as long as exertion levels remain high, the cardiovascular system gets an even more intense workout with even greater fitness benefits. Unlike all other fins, even those with open toe drains, only Force Fin swimming fins are designed to concentrate the force of the blade further back on the foot, using the muscles of the whole leg, not just the lower leg.

Try this simple test to see the difference between how our fins work compared to other brands.

While seated, cross your ankle over your knee, grab your toes and pull them in the direction of the sole of your foot. Do you feel the stretch and tension running from the top of your foot up and along the shin? Those are the primary muscles that other fins work because the fin blade extends from your toes.

Now, grab the foot in both hands – one holding the heel, the other holding the top of the foot – pull again toward the sole of the foot and resist with the leg. The tension has moved up to the upper leg, hasn’t it?

Because of their unique design base don human biomechanics.Fo rce Fins and Slim Fins work the larger muscles of the upper leg in addition to the lower leg. These are the muscle groups you need to develop a strong kick and a better workout.

SWIM FINS