HIGHER PROGRESSION VELOCITY WITHIN THE BREASTSTROKE CYCLE IS A FEATURE OF ELITE SPECIALIST SWIMMERS
Leblanc, H., Seifert, L., Tourny-Chollet, C., & Chollet, D. (2007). Intra-cyclic distance per stroke phase, velocity fluctuations and acceleration time ratio of a breaststroker's hip: a comparison between elite and non-elite swimmers at different race paces. International Journal of Sports Medicine, 28(2), 140-147.
This study compared the movement phases depicted on intra-cyclic velocity graphs of breaststroke swimmers at two skill levels. Two groups of nine male swimmers were videotaped underwater at three swimming paces corresponding to their actual times for the 200-m, 100-m, and 50-m breaststroke races. Their forward intra-cyclic hip velocity was recorded with a velocity meter. The breaststroke cycle was divided into four phases: leg propulsion, leg-arm lag phase, arm propulsion, and arm and leg recovery. Parameters computed were: an index of velocity fluctuations, the distance covered during each stroke phase, and an acceleration-deceleration time ratio.
In both groups of swimmers, when race pace increased the distance covered during the leg-arm lag phase decreased, while the other phases remained stable. When expressed in relative values, the percentage of distance covered during the leg-arm lag phase decreased [the time spent doing little associated with propulsion decreased]. In non-elite swimmers, the percentage of distance covered in the other stroke phases increased significantly, while only a tendency was noted in the elite group. Elite swimmers demonstrated a higher acceleration-deceleration time ratio at the 50-m pace than at their 100-m and 200-m paces. Elite swimmers had higher values for the index of velocity fluctuations and acceleration-deceleration time ratio.
Implication. Breaststroke swimming levels are discriminated by the ability to generate higher progression velocities within the stroke.
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