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Updated: Jun 27, 2026
Swimming Performance Assessment in Fishes
Published on: May 20, 2011
Neuromechanical characteristics of breaststroke in adolescent swimmers across different performance levels: a
Gongju Liu1, Haoshui Zhu2, Jing Ma1
1Key Laboratory of Aquatic Sports Science, General Administration of Sport, Zhejiang College of Sports, Hangzhou, China.
Background:
Breaststroke is technically complex and requires high neuromuscular coordination. Because muscle synergies describe how multiple muscles are organized into low-dimensional activation modules, they provide a functional read-out of neuromuscular control development during adolescence. This study investigated neuromechanical characteristics of adolescent breaststroke swimmers across performance levels.
Methods:
Twenty-six male adolescent breaststroke swimmers were divided into elite (n = 13) and amateur (n = 13) groups. During five 25-m maximal breaststroke trials, two-dimensional underwater video and synchronized surface EMG from 16 muscles were collected. Main outcomes included discrete joint angles, the minimum number of synergies, variance accounted for (VAF), spatial weightings, and temporal activation coefficients. Group differences were assessed using independent-samples or Mann-Whitney U tests, FDR-adjusted spatial-weighting comparisons, SPM1D for activation curves, and Cohen's d effect sizes.
Results:
At v2, the elite group showed greater hip flexion (43.78° ± 6.92° vs. 34.39° ± 11.32°, P = 0.018, d = 1.00), smaller knee flexion (122.93° ± 8.77° vs. 128.93° ± 4.84°, P = 0.041, d = -0.85), and smaller hip abduction (36.28° ± 7.19° vs. 45.22° ± 7.87°, P = 0.006, d = -1.19). VAF was similar between groups (91.27% ± 0.69% vs. 91.20% ± 0.73%, P = 0.583, d = 0.10), whereas the elite group required fewer minimum synergies (5.42 ± 0.72 vs. 6.03 ± 0.66, P < 0.001, d = -0.88). FDR-adjusted spatial-weighting and SPM1D analyses indicated that SYN2 and SYN4 were the main modules distinguishing the groups, with temporal differences concentrated from late glide to in-sweep.
Conclusion:
Performance-related differences mainly reflected lower-limb posture during glide and synergy control during propulsion-related phases. Fewer minimum synergies under comparable VAF conditions suggest greater synergy integration in high-level swimmers. These findings link adolescent breaststroke performance to task-specific multi-muscle coordination.
