Freestyle Kick and Ankle Mobility
Kicking provides stability, improved body position or "lift" (keeping your butt and legs up at the surface of the water instead of dragging below your torso), and forward propulsion in freestyle. It is also one of the more challenging aspects of swimming, particularly for non-swimmers. I have coached innumerable triathletes that hate kicking, often complaining that when they try to kick they feel like they are "moving backwards" (which, to be honest, sometimes they are). This is generally due to poor ankle flexibility.
High-impact exercises (runners...) and sitting for long periods of time both cause ankles to lock up, making plantar flexion (or a fancy way of saying the ability to point your toes) increasingly difficult.
In a number of sports (running, lifting) dorsiflexion is heavily emphasized, and plantar flexion tends to fall second. In swimming, however, plantar flexion is incredibly important.
There is all sorts of biomechanics and physics that explain the importance of ankle flexibility in freestyle kick, and approximately 4 billion articles explaining all of that (a few of which I will link to below). But here I am just going to show you a quick video of what a proper freestyle kick looks like, and introduce a couple of quick, easy exercises you can do to improve general ankle mobility.
First off, this is what a proper freestyle kick looks like:
To watch the complete minute+ version of this video, go here.
The main thing I want you to notice is the motion of his entire leg, through his toes, during the kick. His feet are relaxed, not rigid, changing position throughout the course of the kick. Often times people will kick from the knees (a topic for another post), or solely from the hips (totally straight legs). BUT I will have additional posts for how to avoid kicking from your knees or hips, today we are just talking about those feet.
So, if you are one of those swimmers struggling with getting your foot to move in the motion above, what are some things you can do to improve your kick and ankle flexibility?
IN THE WATER
Kick often (duh) - Practice makes perfect.
Wall Kicking - Hold onto the wall, face in the water, body position level with the surface, and kick. You won't sink because you are holding onto the wall, and you can play with different techniques and see how they feel, which ones make it easier to maintain your body position, etc.
Kick or swim with fins - This is one of the primary reasons I heavily encourage beginner swimmers to invest in a pair of fins. In addition to allowing swimmers to get a better feel of what your body position and stroke SHOULD feel like (which I touch on in my fins post), kicking with fins can also pull your ankles into plantar flexion, increasing mobility and giving the swimmer a sense of what proper foot position feels like.
WHILE YOU ARE AT HOME WATCHING REAL HOUSEWIVES
Roll and stretch out those calves - Using the wall, a step, or a foam roller (or tennis ball), get those calves and achilles tendons loosened up.
Stretch out the plantar fascia (the bottom of your foot) - take a golf ball (or baseball) and, sitting in a chair with your feet on the ground, roll the ball around under the arch of your foot for a minute or two with each foot.
Spell the alphabet - try sitting in a chair with one foot propped off the ground, spell out the alphabet in the air with your toes. Don't forget to do both feet.
Towel pick up - still sitting in that chair, throw a towel down on the floor and grab the center of the towel with your toes, curling it towards your body. Do that 5x with each foot.
Point your toes and flex your feet - Sit on the floor with your legs stretched out in front of you. Pull your toes toward you then return to neutral, 10x. Then gently point your toes away from you and return to neutral, 10x.
Ankle strength and mobility is super important for life in general. This stuff is good for you even if you don't see any sort of kickboard in your future.
Links with info about kicking and ankles from a few different sources:
Working on Ankle Flexibility with an Olympian
Triathlete: Why It's Important to Conquer the Kick
10 Must Know Tips for Ankle Mobility (Swimming World)
Dryland Tip: How to Improve Ankle Flexibility (YourSwimBook)