The flutter kick is a simple motion, but like many other parts of swimming is often done incorrectly. The power of the flutter kick comes from the larger muscles of the upper leg and hip, including the Gluteus Maximus, Gluteus Medius, Pectineus, Adductor Longus, ErectusFfemoris, and well, all of them. In order to deliver the most power, the swimmer needs to keep their knees predominantly straight with a flexible ankle. There are three common mistakes made by swimmers:
- Kicking from the knee versus the hips: Many swimmers are generating the kick by flexing and extending the knee. This motion may look correct from the surface, to the uninitiated, but it does not have the power that the larger muscles of the hips and upper legs. You want to keep your knee straight but not locked , think of a branch blowing in the wind, you have to bend with the wind but not break allowing the ankle to deliver the power (more on the ankle below).
- Dorsi flexing the ankle: This mistake, common in men who have not done an activity that promoted ankle plantar flexion (pointed toes). If you can’t sit on your feet you may not be flexible enough to perform an effective flutter kick.
- Making the kick to large: The size of your kick, from top to bottom, should be about the size of a shoe box. The common mistake it to make your kick to large. Keep your kick smaller and quick.
For the best flutter kick, keep your knees straight, but not locked, your toes a relaxed pointed and keep the kick small and quick.
Up Next: Why you must train multiple strokes, even if you only compete in one.