A proper flutter kick is one of the most important keys to an efficient, fast and enjoyable freestyle swimming experience; however, it is also one of the hardest parts of the freestyle stroke to learn.
I’ve taught countless individuals with varying skill levels and everyone is different in the way they understand how the kick should be performed.
Some get it right away and they move on in their swimming skill learning program, others struggle with the right leg motion which hinders their progress during the other swim exercises.
Unfortunately, everyone learns in a different way so there is no single technique or sequence of drills which will work for everyone.
Before you start, it is important you understand what it is that propels you forward.
Many beginner swimmers start by using the so-called "bicycle kick" which causes the swimmer to kick water backward in the opposite direction to where they want to go.
As much as it makes a logical sense to kick the water behind you, it will get you going very slowly and it is very bad in terms of efficiency, effectiveness. Most importantly, it does a horrible thing to your proper swimming body position.
Imagine running in the water, but instead of being vertical, doing it horizontally. Not a pretty sight, is it :)?
So, where else can you kick the water if not behind you? Well, how about down and up.
Think about a fish and its tail (it either moves from side to side or up and down).
So, pointer number one is to make sure you kick down and up and not only behind you.
You can visualize a dolphin swimming with the caudal fin moving up and down to propel the dolphin forward.
A word of caution here though, do not get into the habit of kicking to the sides instead of up and down as you will end up with a so-called scissor kick which is ugly and inefficient.
Now you know a part of the very basic principle of how you go forward during flutter kick, but like everything in swimming, it is not that simple.
What part of the leg and foot do you move and when etc. etc.?
These are the questions that need to be answered in order for you to understand how the proper freestyle kick is done. So, let's break it down a little bit more.
Freestyle kick actually utilizes the entire leg from hip to toe.
Each part of the leg plays a specific part in your kick movement.
As you might have guessed, the kick starts from the hip and continues to the knee and then finishes with an ankle (a relaxed ankle).
Imagine a garden hose with both ends loose, laying in your favorite garden area.
Grab one end of the garden hose with one hand and start moving your arm up and down. This up and down movement will produce a series of snapping waves that travel down the garden hose to the other end.
Each of the waves is basically one kick in terms of freestyle. It starts at your hip (the hand that holds the garden hose) then the wave continues through your knee and finishes at the ankle.
Obviously, the garden hose waves are much larger than the actual kick, but you get the picture, right?
Another analogy could be taken from football (soccer) where hip, knee, and ankle are used to kick the football (soccer ball). The footballer (soccer player) starts the kick with his hip motion, then knee, then ankle and then the foot connects with the ball.
Now, you hopefully have a little better understanding of how the flutter kick is performed.
However, obviously, it is much easier said than done, so practice practice practice.
To practice the freestyle kick motion as described above, you should first try the wrong approach, so that you can feel how it should not be done.
You have already tried the bicycle kick as I mentioned above and probably the scissor kick, so you know how they feel.
Bad. Very bad.
Now, try kicking only from your knees.
Pretend as if you are laying on the floor face down and you bend your knee with your heel to your butt and then kick down with your foot to the ground and continue doing so.
You will feel certain propulsion forward, but you also find that you are forced to lift your feet out of the water which forces your lower body further down into the water which is not an ideal body position.
Then you can try the other extreme, where you try kicking with straight knees and only with your hips.
You will find that with this kick you will not go anywhere and your legs will more than likely quickly kick themselves all the way to the bottom of the pool.
If you combine these two wrong kick types (hip only and knee only) and meet somewhere in the middle, you should be very close to having the right kick.
Try starting out with straight legs and only using your hips to kick and then slowly loosen up your knee joint, so your leg from the knee down gives in a little when you kick down.
In the video below you will see a few different kicking styles. Some worse than others, but recognizing the wrong mechanics is the first step in having a good kick.
Did I mention that during the flutter kick, your ankle should be relaxed and your toes always pointing toward the opposite direction of where you are going?
Well, now I have.
Keeping your ankle relaxed throughout the kick is important as it increases the flexibility of the ankle and it also maximizes the surface of your foot so you can kick more water.
Try it out.
Do a freestyle kick with a very tight ankle as if you were a ballerina.
Then perform a kick with a loose ankle and see the difference.
To better understand how big a role ankle flexibility and relaxation plays in the freestyle kick, perform a kick where you point your toes to the bottom of the pool so you have a 90-degree angle in your ankle.
This definitely does not work, does it?
Last, but not least, you might be wondering how wide the kick should be.
Easy as 1, 2, 3!
Just imagine that your feet are in a bucket and you cannot kick past the outer perimeter.
So we are talking about 30 cm or 12 inches apart at most.
In fact, stay away from spreading your legs like wings of a bald eagle.
There are a couple of great tools that you can use to improve your kicking.
First, forget about the kickboard (shove it back into your closet and never take it out).
Do all the kicking in a tree log position.
Second, you can use special fins that help you with balance and with lifting your hips to the surface.
These leg fins are called shinfins.
Finally, if you have mastered the basics, why not try out zoomers.
Zoomers will add more power to your kick.
I've covered only the basics here, so rest assured there is a bit more to freestyle kicking than just what is written in this post, however, if you master the kicking basics, the rest is much, much easier to learn.