Muscle Activation in World-Champion, World-Class, and National Breaststroke Swimmers

Area of Science:

• Sports Science
• Biomechanics
• Human Movement

Background:

• Understanding elite athletic performance requires detailed analysis of biomechanical and neuromuscular factors.
• Breaststroke swimming, a complex aquatic skill, relies on precise coordination of muscle activation and limb movements.

Purpose of the Study:

• To identify performance-differentiating muscle-activation patterns and kinematics in world-class versus national elite breaststroke swimmers.
• To analyze electromyography (EMG) and kinematic data during maximal effort breaststroke to find key performance discriminants.

Main Methods:

• Surface electromyography (sEMG) was used to record activity in 8 muscles of 4 world-class and 4 national elite breaststroke swimmers.
• Swimmers performed a 25-m breaststroke at maximal effort, with kinematic data collected concurrently with EMG.

Main Results:

• World-class swimmers demonstrated shorter leg recovery duration, smaller knee angles at recovery onset, and faster leg glide velocity.
• Significant differences in muscle activation patterns were observed across all 8 muscles between world-class and national elite groups.
• Specific differences included reduced triceps brachii activation during leg propulsion and distinct patterns in rectus femoris, gastrocnemius, pectoralis major, biceps femoris, and tibialis anterior activation.

Conclusions:

• Identified muscle-activation and kinematic differences serve as crucial performance discriminants in breaststroke.
• These findings can inform targeted training to improve breaststroke technique and kinematics across different phases.
• The results provide valuable insights for coaching and teaching breaststroke, especially for novice swimmers.