So the very first step is hamstring curl. It’s the start of every breaststroke kick, and what you do is you take the legs from a standing position or side by side, and you start bending at the knees and you bring the heels up to the bottom. So you can see on this picture on the lower left, how her legs are not very close together, they could be tighter but starts in the straight-line position, and then brings those heels up towards the bottom by bending the knee, that is the hamstring portion of the breaststroke. You’re also combining a little bit of backing extension because you’re shifting the hip forward and dropping as well. But the hamstring curl is the biggest component here while firing your glutes to get the heels up to the bottom to complete this step, a swimmer must think about bending their knees, so you have to bend your knees to get the heels up. There is no way around it.