Biomechanical analysis of the breaststroke start

Area of Science:

• Sports Science
• Biomechanics
• Swimming Performance

Background:

• The breaststroke start is a critical phase influencing overall race time.
• Understanding the kinematic and coordination differences between skill levels can optimize training.
• Previous research has not comprehensively analyzed breaststroke start technique across different competitive levels.

Purpose of the Study:

• To analyze and compare the kinematics and coordination of the breaststroke start between national and international level swimmers.
• To identify specific technical elements contributing to faster start times.
• To provide insights for coaches and swimmers to improve breaststroke start performance.

Main Methods:

• Video analysis of ten national swimmers and one international swimmer performing a 25m simulated 100m pace grab start.
• Kinematic analysis of key phases: block leave, flight, entry, glide, pull-out, and swim to 15m.
• Coordination analysis of arm-thigh proximity, arm recovery to leg propulsion timing, and leg to arm propulsion timing.

Main Results:

• The international swimmer achieved a significantly shorter 15m start time compared to national swimmers.
• Shorter swim phase duration and longer underwater phase duration were observed in the international swimmer.
• The international swimmer exhibited longer durations of arms close to thighs and body glide in extension.
• A negative superposition of leg propulsion with arm recovery was observed during the pull-out phase for all swimmers, resolving by the first swim stroke.

Conclusions:

• Skill level significantly impacts breaststroke start kinematics and coordination.
• Optimized underwater phases, extended glide, and specific arm-body positioning contribute to a faster breaststroke start.
• The international swimmer's technique suggests that longer underwater phases and controlled body extension are advantageous for elite performance.