Take Home Points on Kick Timing in Butterfly
Many realize swimmers do not pull their arm past their body, but anchor their arm and move their body past their arm. Despite this knowledge, implementing this strategy is difficult, especially on butterfly. Now, everyone around a pool deck has heard the comment "anchor the arm, then swim past it", but often times this cue falls short of improvement.
In swimming, understanding physics may help highlight ideal biomechanics. For me, physics and knowledge of forces helped me understand a "hip-driven" freestyle stroke and is now unlocking the idea of swimming past my arms on butterfly. Before you move on, make sure to read "How to swim the butterfly" for an indepth review of butterfly biomechanics. This piece goes over a lot of information, yet the timing of the kick and role of the kick with the catch is absent, a vital flaw. The kick, as written, should be small and fast. Ideally, the kick helps counteract the actions of the arms and orients the body horizontal, an ideal position for forward propulsion.
Just before hand entry, the first kick occurs. This motion helps counteract the action of the arms, but also raises the hips and body for the first propulsive phase. Once again, orienting the body in a horizontal position is a must, as this provides streamline for the swimmer as their arms gain propulsion. The kick during the entry counteracts the vertical forces which act upon the arms.
The second kick happens as the hands finish the catch phase. This kick maintains an elevated hip position. This kicks helps keep the hips high, the body in a relative streamline, as the chest and head rose for a breath.
Many perform large kicks during the butterfly, but this is likely unnecessary, bringing the body out of streamline. Although it may help some swimmers time their streamline during propulsion of the catch, it is still wasteful and beneficial if eliminated. Remember, small, fast kicks which counterbalance the arms and streamline the body optimize butterfly horizontal velocity.
Written by G. John Mullen who received his Doctorate in Physical at University of Southern California (USC) and is a certified strength and conditioning specialist (CSCS). At USC, he was a clinical research assistant performing research on adolescent diabetes, lung adaptations to swimming, and swimming biomechanics. G. John has been featured in Swimming World Magazine, Swimmer Magazine, and the International Society of Swim Coaches Journal. He is currently the owner of COR, providing Physical Therapy, Personal Training, and Swim Lessons to swimmers and athletes of all skills and ages. He is also the creator of the Swimmer's Shoulder System, Swimming Science, Swimming Science Research Review, Mobility System and the Swimming Troubleshooting System.