Muscle coordination during breaststroke swimming: Comparison between elite swimmers and beginners

Area of Science:

• Biomechanics
• Sports Science
• Motor Control

Background:

• Understanding muscle coordination is crucial for optimizing swimming performance.
• Breaststroke swimming involves complex interplay between upper and lower limb movements.
• Expertise level significantly influences motor control strategies.

Purpose of the Study:

• To compare muscle coordination strategies in upper and lower limbs between elite and beginner breaststroke swimmers.
• To identify differences in muscle synergies and activation timing.
• To investigate the impact of expertise on the temporal and spatial organization of muscle activity.

Main Methods:

• Surface electromyography (EMG) recorded from eight muscles in 16 swimmers (8 elite, 8 beginners).
• Swimmers performed a 25m breaststroke at maximal effort.
• A decomposition algorithm identified muscle synergies; similarity indices and lag times were calculated.

Main Results:

• Individual muscle patterns showed moderate to high similarity between groups (0.61–0.84).
• Beginners displayed significantly earlier activation in pectoralis major, biceps brachii, rectus femoris, and tibialis anterior.
• A backward shift in the second muscle synergy was observed in beginners, suggesting altered arm-leg coordination.

Conclusions:

• Synergistic muscle organization in breaststroke is largely unaffected by expertise.
• Specific timing adjustments in muscle activation and inter-limb coordination differentiate beginners from elite swimmers.
• Expertise influences the fine-tuning of muscle activation timing rather than the fundamental synergistic patterns.