Effect of Adding a Dolphin Kick to a Breaststroke Pullout
Scott McLean, Southwestern University
Rod Havriluk, Swimming Technology Research
Steve Brandt, Southwestern University
USA Swimming Grant, 2006-2007
Medicine and Science in Sports and Exercise, 2008, 40(5).
PURPOSE: To assess the effect of adding a dolphin kick to a breaststroke pullout.
METHODS: Eleven (20.9±2.3 yrs, 1.86±0.05 m, 79.6±5.5 kg) swimmers experienced with performing traditional and dolphin kick breaststroke pullouts participated in the study. Underwater video analysis was used to track whole body center of mass kinematics during a pullout. Time for the center of mass to travel distances ranging from 2.5-4 m from the initiation of the pullout were computed. Hand force data were derived from differential pressure measurements during the pulling phase of the pullout.
RESULTS: Use of a dolphin kick in a breaststroke pullout significantly (p=0.016) improved performance. Time for the center of mass to travel 4m after the initiation of the pull was reduced by 0.19 s. This performance improvement was not attributable to enhanced force production from the pull. Hand force was not significantly different between pullout techniques for the right hand (p=0.142) nor left hand (p=0.303). Total impulse produced by the pull was reduced by 3.6% (p=0.039, ES=0.34) when using the dolphin kick pullout.
CONCLUSION: These data suggest that the use of a dolphin kick during a breaststroke pullout provides a significant advantage over the traditional no-dolphin kick pullout. Furthermore, this advantage comes from enhanced propulsion from the kick but not the pull.
Supported by USA Swimming Science and Technology Seed Grant.