# The Proof of Coupling Motions

For several years I have written many Aqua Notes at The Race Club pertaining to coupling. I have come to believe that coupling motions are extremely important in swimming all four strokes and on the start to enhance power. I have never been able to prove that belief is correct…..until now.
Recently we invested in some technology at The Race Club that enables us to measure propulsion (pressure) on the hands during the pulling motion. The technology also measures the speed and degree of body rotation (angular velocity) with each stroke. We synchronize those measurements precisely with the swimmer’s video so we can see how much propulsion and body rotation are happening at each .02 seconds during the stroke cycle. No one has ever done that before. We call this technology the Pressure Meter and it is now available to any swimmer that wants to use it at The Race Club.
This week, in Lanes 2, 3, and 4, you will see in our webisode how one of the three and perhaps the most powerful coupling motions on the start, the back-leg kick, has a profound impact on the start of elite sprinter, Aaron Greenberg.
Aaron had never used a meaningful back leg kick in his sprint career until we recently worked with him. In just two hours, he completely changed the intensity and height of his back-leg kick, resulting in greater peak velocity and acceleration off the block, as well as increasing his distance to entry and decreasing his time to breakout. Using Velocity Meter technology, we were able to compare Aaron’s old start with the new one. You will find all of the details of the outcome of this comparison, along with a comparison with Brad Tandy’s start, on this new webisode.
As interesting as that information might be, since we didn’t actually measure the forces off of the starting block, it doesn’t necessarily prove that the leg kick increased those forces, even though the back-leg kick was the primary difference in the two start techniques. It is suggestive, but not proof.
When we recently tested several elite athletes from Indiana University’s post grad program, we used the Pressure Meter technology for the first time. Soon, we will release our first webisode publicly on this technology that does prove the relationship between coupling energy and pulling propulsion, showing Zane Grothe, one of the world’s fastest distance freestylers, and Margo Geer, one of America’s top female sprinters.
We are excited to share this new information with you. Hop in Lanes 2, 3 or 4 to check out the back-leg kick and enjoy our entire library of great swimming technique videos. Stay tuned!
Yours in swimming,
Gary Sr.

https://theraceclub.com/video/velocity-meter-aaron-greenberg-start/