On-block mechanistic determinants of start performance in high performance swimmers

ABSTRACT

This study aimed to 1) identify what starting block outcome kinetics have the greatest relationship to 15 m start time; 2) investigate key mechanistic determinants of the block phase and how these forces are sequenced. One hundred and fifty-two high-level competitive swimmers were included in the study. Linear mixed modelling identified four on-block outcome kinetic variables (work, average power, horizontal take-off velocity (HTOV), and average acceleration) as having a very large relationship (R² = 0.79–0.83) to 15 m start time, with average power having the most substantial impact. On-block force sequencing started with the rear leg, followed by upper limb grab forces and the front leg. Further exploration of underlying determinants was performed for average power and HTOV of the centre of mass. Multiple linear regression identified grab resultant peak force, rear resultant average force, front horizontal peak force, and resultant peak force as significant predictors of average power (R² = 0.88). HTOV was predicted using the same variables, apart from the inclusion of rear horizontal peak force instead of rear resultant average force (R² = 0.73). These findings may influence how strength and conditioning and skill acquisition interventions are designed to improve swim start performance.

KEYWORDS:

• Swimming
• swim start
• block phase
• force plate
• kinetics

Acknowledgments

The authors would like to thank the participants for being part of this project.

Disclosure statement

Justin Keogh is on the editorial board of Sports Biomechanics.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Queensland Academy of Sport’s Sport Performance Innovation and Knowledge Excellence Unit in conjunction with Bond University Faculty of Health Sciences and Medicine.