3. RESULTS The 10 analysed regular and accelerated backward giant circles for each gymnast were very consistent in terms of overall duration, timing and magnitude of the hip and shoulder actions (Table 1 and Figure 4). When the data from each trial were normalised to total duration the average standard deviations for the times at maximum and minimum joint angles changed by less than 1 ms. Table 1. Point by point standard deviations for the shoulder and hip angles across all trials for each gymnast and giant circle type Group Regular SD Accelerated SD Shoulder [°] Hip [°] Shoulder [°] Hip [°] Most Elite 0.9° 1.4° 1.5° 1.9° 1.4° 1.5° 1.4° 1.7° Less Elite 1.3° 1.4° 1.1° 1.5° 1.7° 3.1° 1.1° 1.7° Mean 1.4° 2.0° 1.3° 1.7° regular accelerated Figure 4. Time histories of the hip (grey lines) and shoulder (black lines) angles of all 10 trials for the regular and accelerated giant circles by (a) the most elite gymnast through to (d) the least elite gymnast. For the regular giant circles the standard deviations at the instants of maximum and minimum hip and shoulder angle ranged from 5 – 192 ms and 1 - 5° for timings and angles respectively (Tables 2 and 3). For the accelerated giant circles the same ranges of standard deviations were 4 – 23 ms and 1 – 3° respectively (Tables 2 and 3). The deviations in the accelerated giant circles were relatively small for all gymnasts. The smallest temporal standard deviation for the most elite gymnast in group 1 was 4 ms for accelerated circles (Table 2, hip min ④). The corresponding range of deviations of the 10 trials about the average joint angle time history ranged from 1 – 9 ms. On the other hand, the range for his shoulder action with the largest temporal standard deviation, 18 ms for accelerated circles (Table 2, shoulder max ①), was 2 – 26 ms. The two corresponding ranges for the least elite gymnast in group 2 (less elite group) were 1 – 22 ms and 1 – 30 ms respectively.
Table 2. Standard deviation of the temporal instants of maximum and minimum hip and shoulder joint angle for both types of giant circles Circle type Group Hip Max ① Hip Min ② Hip Max ③ Hip Min ④ Shld Max ① Shld Min ② Shld Max ③ Shld Min/Inflex ④ [ms] [ms] [ms] [ms] [ms] [ms] [ms] [ms] Reg. Most Elite 10 5 174 65 31 14 72 34 4 6 192 90 7 11 74 72 Less Elite 15 10 130 50 24 9 94 76 15 9 36 112 34 9 66 104 Mean 11 7 133 79 24 11 76 72 Accel. Most Elite 6 18 7 4 18 11 6 12 14 10 8 8 11 19 8 15 Less Elite 7 9 9 11 12 9 10 12 17 11 15 13 21 13 14 23 Mean 11 12 10 9 15 13 9 16 There was a significant difference in the movement variability of the important aspects of technique for both types of giant circles between the two groups of gymnasts (F(2, 5) = 10.2, p = 0.02). That is, the more elite gymnasts had lower movement variability than the less elite gymnasts in the mechanically important aspects of technique. There was, however, no significant difference between the movement variability of the less important aspects of both types of giant circles between the two groups of gymnasts (F(2, 5) = 0.07, p = 0.93). In other words, all gymnasts appeared to have a similar level of variability in the less important aspects, however, some of the differences do warrant further consideration. Although the range of movement variability appeared to be larger during the regular giant circles (Table 2), there was no significant difference in the movement variability of the mechanically important aspects between the two types of giant circles (F(2,5) = 1.38, p = 0.33). That is, in the important aspects of technique the gymnasts had similar amounts of variability for both the high and low complexity tasks. There was, however, a significant difference in the level of movement variability between the two skills in the less important aspects (F(2,5) = 76.5, p < 0.01). That is, there was more variability in the less important aspects of the regular giant circles compared to the less important aspects of the accelerated giant circles.