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.
CONCLUSIONS: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.
Sadly, this is the current rule. Given that the Olympians do their butterfly kick first under a similarly worded rule
I think there's a little gray area in that the kick might be considered to occur only when the legs start to go down. Remember there's wording in there about a "downward dolphin." The wording has been changed slightly, but there is still mention of this. So, if this is true, these swimmer might look to be doing an illegal kick, but if they start the downward portion of the kick to coincide with the arm pull then it might actually be legal.
Here's the FINA rule:
SW 7.4 During each complete cycle, some part of the swimmer's head shall break the surface of the water. After the start and after each turn, the swimmer may take one arm stroke completely back to the legs. The head must break the surface of the water before the hands turn inward at the widest part of the second stroke. A single downward dolphin kick followed by a breaststroke kick is permitted while wholly submerged. Following which, all movements of the legs shall be simultaneous and in the same horizontal plane without alternating movement.
Interpretation: A dolphin kick is not part of the cycle and is only permitted at the start and turn whilst the arms are pulling back to the legs or after the arm pull whilst wholly submerged followed by a breaststroke kick.
Sadly, this is the current rule. Given that the Olympians do their butterfly kick first under a similarly worded rule
I think there's a little gray area in that the kick might be considered to occur only when the legs start to go down. Remember there's wording in there about a "downward dolphin." The wording has been changed slightly, but there is still mention of this. So, if this is true, these swimmer might look to be doing an illegal kick, but if they start the downward portion of the kick to coincide with the arm pull then it might actually be legal.
Here's the FINA rule:
SW 7.4 During each complete cycle, some part of the swimmer's head shall break the surface of the water. After the start and after each turn, the swimmer may take one arm stroke completely back to the legs. The head must break the surface of the water before the hands turn inward at the widest part of the second stroke. A single downward dolphin kick followed by a breaststroke kick is permitted while wholly submerged. Following which, all movements of the legs shall be simultaneous and in the same horizontal plane without alternating movement.
Interpretation: A dolphin kick is not part of the cycle and is only permitted at the start and turn whilst the arms are pulling back to the legs or after the arm pull whilst wholly submerged followed by a breaststroke kick.
