Background:It is difficult to know exactly what the differences were between the right and left hand when swimming. As there is a flume providing steady flow and the 3 Line Analysis
and Testing System. It can be used to train athletes, capture the videos and analyze the speed. The coach can know more about the athletes’ performance in the flume, which can provide more effective
information to improve the athlete’s technique. In that case, we did some research on the difference of the left and right arms in front-crawl in the flume with the 3 Line Analysis and Testing System.
Methods:Participants: Six girl young athletes (age14.8±2.8 years, height 1.66±0.21 m, body mass 49.6+3.1 kg; m±s).
Swim trials: In the flume pool, each swimmer performed swim trials with 1.45m/s and 1.55m/s using the front-crawl. In each trial, the swimmer was required to swim 30 seconds and the relative speed was
recorded by the 3 Line Analysis and Testing System.
Dynamic analysis: One camera filmed the swimmer from a side view with the frequency of 25 Hz. The 3 Line Analysis and Testing System was used to record the speed.
The movement of the arm was broken down into four phases to describe the whole process of stroke.
The efficiency index was defined as velocity plus length of every phase to estimate the efficiency of left or right arms in different phases.
Results:1. The percentage of each phase
The analysis of the percentage of each phase in time domain showed that no matter swimming in 1.45m/s or 1.55m/s, phase T1 cost more time than other phases, and phase T2 cost the least. Also, with the
speed increasing, phase T2 and T3 cost more time, while the percentage of phase T1 and T4 decreased. On the opposite, Li’s research showed the percentage of T2 and T3 decrease with the flow going
2. The efficiency index of different phases
We compared the efficiency index of different phases.The resault showed when the speed was low, the efficiency index was nearly the same. When the speed increased, it showed differences between the
left and right arms. And with the flow’s speed increased, the efficiency improved, which was the same as reported.
3.The average speed of each phase. The body speed increased with the flow going up, and in phase T3 the body speed was higher than that in other phases. When swimming in 1.45m/s or 1.55m/s, athletes
had the lowest average speed in phase T2. While in phase T1, the speed increased most, about 6.6%. We thought it may be hard to control the arms technique well when swimming on low speed, so when
swimming on 1.45m/s the difference between the right and left arms were more than that in the speed of 1.55m/s.
1. When swimming in low speed, the left and right arms showed fewer differences in each phase.
2. When swimming in higher speed, it showed differences between the left and right arms, especially in phase T1.
3. The reality differences between the left and right arms depend on athletes. More researches were needed to make further analysis in order to improve the young athletes’ technique.