ONE Method Ensures Chest Connection for Underwater Undulation

By SwimSwam Partner Content
January 18th, 2018
Swimming gear news courtesy of SwimmersBest, a SwimSwam partner

Science shows that underwater undulations are best when swimmers imitated eels and engage each undulation from the chest area to create a propulsive wave with the body. This stands in contrast to the more traditional idea of a “body dolphin.” Body dolphin undulation creates propulsion primarily from knee kicks; this knee kick concept has a forward “propulsive phase” and a backward “recovery phase,” which greatly hinders the efficiency of undulation.

The process of a chest-lead body undulation generates opposing lines of force on each side of the body that ripple down the body to generate consistent propulsions. This eel-like undulation requires the swimmer to: finish each undulation past the midline in both the forward and backward phases, keep the ankles extended to finish each undulation, start each undulation from the chest/rib area, and engage muscles on the “recovery phase” of each undulation.

To help generate “feel,” muscle engagement, and muscle memory, SwimmersBest invented the Eel-fin, both a Regular and a Pro version. The SwimmersBest Regular Eel-Fin incorporates a moveable weight that acts as a pendulum to train novice swimmers to properly undulate to the front and back of their midline by feeling the shifting weight. In this situation, the weight acts as a pendulum like in a grandfather clock. As the weight is moved closer to the feet, the undulation rate quickens, and the size of the undulation decreases to help calibrate swimmers to the scientifically-proven rate of 0.40 to 0.45 seconds per undulation.

The newest member of the SwimmersBest Eel-Fin product line is the Pro Eel-Fin, a shorter and wider version of the Regular Eel-Fin. The Pro is used to create the muscle memory of straight ankles and closer knees and is designed for strong, efficiently-undulating swimmers that are 13+ years of age. On top of that, the Pro version allows the heels of the feet to naturally pivot outward into the propulsive phase and forces strong muscle development in the recovery phase. Through these features, the Pro Eel-Fin is the final measure to ensure powerful undulations starting from the chest with a consistent wave through to the toes.

A further immense advantage of the Pro Eel-Fin is its ability to connect the body core to the full butterfly stroke. By helping to elongate both phases of the butterfly “kick,” the swimmer is encouraged to create a smaller amplitude undulation by engaging a range of core muscles throughout the stroke cycle. The Pro version is now being used by a host of Division 1 college teams and age group teams alike.