Higher Backstroke Ledge Height Improves the Early Phase of Backstroke Start Performance in Competitive Swimming

Area of Science:

• Sports Science
• Biomechanics
• Swimming Performance

Background:

• The backstroke start is crucial for competitive swimming.
• Backstroke ledge (BSL) use is suggested to enhance starts, but optimal height is unknown.

Purpose of the Study:

• To investigate the impact of different backstroke ledge heights on start performance.
• To analyze flight distance, entry posture, and 5m split times.

Main Methods:

• Eleven male swimmers performed backstroke starts with BSL heights at +0.04m (High), 0m (Medium), and -0.04m (Low).
• Whole-body kinematics, including center-of-mass (CM) height and velocity at takeoff, were analyzed using high-speed video cameras.

Main Results:

• The High BSL trial significantly reduced 5m split times compared to the Low BSL trial.
• Higher takeoff CM height and horizontal velocity were observed with the High BSL, extending flight distance.
• Improved upper-body water-entry posture was noted with higher BSL, though overall body posture showed no significant difference.

Conclusions:

• Elevating the BSL above the water surface enhances backstroke start performance.
• Increased flight distance is achieved by optimizing CM vertical position and horizontal velocity at takeoff.
• Swimmers should consider utilizing higher BSL settings to improve their start efficiency.