Background:This paper analyzes the effect a straight knee kick has on the production of lactate acid during elite level backstroke competitions. Using results from Lactate ProTM we
With proper technique the straight-knee butterfly kick can increase speed and proper training will be able to mitigate the excess production of lactate acid.
Methods:We collect stroke and lactate date from several elite level swimmers during practice and competition. Kick speed is analyzed by Kinovea (0.8.15, 1GHz, 256Mo) the butterfly
kick s with a 1/500sec frequency and underwater high speed HD camera (Panasonic HDM:1080i 720p 480pHX-WA30). The lactate test after a 50seconds wall kick with a tempo of 1.10sec/stroke measured by a
FINIS tempo machine. The subjects lactate data is generated by the Lactate ProTM LT-1710 (Arkray, 5μl, Kyoto, Japan) meter for on-farm determination of the blood lactate of teleost fishes. Blood
lactate of farmed cod, caught by rod and line, was below detection limits of the meter (< 0.8 mM), and confirmed by laboratory assay as 0.459 ± 0.037 mM (mean ± SEM, n = 34).
The data for the straightness knee backstroke kick speed and the lactate test are collected during a 60second wall kick, where tempo is 1.10-1.20sec/stroke measured by the FINIS tempo machine. The
one stroke velocity, distance per stroke, and max speed data is collected from two 25 meter backstroke swims after a race start. The first 15 meters were completed under water using the dolphin kick
and the final 10 meters are completed at maximum effort.
Results:When measuring the effects of straight-knee butterfly kick, we find the proportion of kicks greater than 170 degrees knee-bending increase from 12.5% to 67.4% and knee angle
average 151.15degree to 171.06 degree, distance per cycle (DPC) improved from 2.12±9M/C to 1.93±12M/C, in the race distance per cycle 2.04M/C to 2.17M/C, Wilcoxon/Mann-Whitney.: 4.766278, p ≤0.01. The
elbow angles of >170 degrees elbow-bending from 25.3% to 60.3%, Wilcoxon/Mann-Whitney.: 4.776403, p ≤0.01, but the straightness knee backstroke kick increased lactate acid 6.1mmol/l compared to the
bending knee backstroke kick 4.3mmol/l.
Conclusions:Backstroke performance seems to be associated to the straight elbow and straight knee in elite world class swimmers. Butterfly performance improved through possible
reasons are less resistance equal to increase the distance per cycle in the championship meet races. The results of this paper reveal that with proper training and technique, the straight knee
backstroke kick can result in much faster 100 meter backstroke times for swimmer able to mitigate the increase in lactic acid production during competition.