Leg fins lift your knees & straighten your kick. So your swimming feels a lot more streamlined without your knees dragging through the water. They give you a better kick for freestyle, backstroke and fly.
Because regular foot fins are on your feet, they sink your knees down too far in the water when you swim. They also make you bend your knees too much. You can feel your knees dragging through the water. So they don’t give you a better kick. Instead, foot flippers force you to do a different kick to good swimming without fins.
Good squad swimmers keep their knees much higher and straighter, and they swim a lot faster. However, you see many swimmers at the pool who kick with low, bent knees. So their kick feels inefficient and lacking in power. This is a common problem for swimmers, even without fins. But foot flippers make it worse.
Leg fins overcome these problems because they attach to your legs. So the water flow over the fins lifts your knees up. If you fit them a bit higher, they lift your knees up more. This even works at slow speeds. It also works even if you don’t kick and just pull with your arms. They give you higher knees and straighter knees, for a better kick for freestyle, fly and backstroke. A better kick helps you to improve your arm pull as well. So these fins speed up your whole stroke swimming.
Your body remembers your higher knees, straighter knees and better kick, even after you take off your leg fins. So they give you a better kick for your normal swimming without fins too.
Now you can have fins for extra speed and have higher knees, straighter knees and a better kick!
See related FAQ about higher, straighter hips to improve your kick.
See all FAQ about smooth forces for faster swimming.