Monitoring sprint-paddling technique in elite and sub-elite surfers using inertial sensors

Abstract Surfboard sprint-paddling is considered critical for surfing performance, yet sprint-paddling kinematics of surfers across competition levels remain underexplored. Inertial measurement units provide a novel approach to assessing sprint-paddling trunk and surfboard kinematics, and velocity profiles. Inertial measurement units also present future opportunities to explore whole-body sprint-paddling kinematics and offer practical application in real-world environments, including ocean-based settings. Thirteen elite and nine sub-elite surfers completed maximal 15-m sprint-paddling trials where split times were recorded. Inertial measurement units were secured to thoracic (T3–T4) and sacrum regions, and the surfboard’s nose. Intracycle roll, pitch and yaw angles, angle differences between inertial measurement unit locations, and intracycle velocity variations during sprint-paddling trials were determined. Inferential and mixed-effects model analyses revealed significant differences between elite ( n = 13) and sub-elite ( n = 9) surfers and between sexes ( n = 9 female; n = 13 male). Elite surfers were significantly faster sprint-paddlers than sub-elite surfers within both sexes and exhibited greater thoracic yaw and larger differences between thoracic versus sacrum and surfboard yaw. Elite and sub-elite females exhibited no difference in overall movement profile, while elite males demonstrated greater thoracic movement compared to sub-elite males. Irrespective of competition level, males exhibited greater thoracic pitch and yaw, lesser surfboard roll, and lesser difference between thoracic and surfboard roll compared to females. These findings emphasize the importance of trunk control and maneuverability during sprint-paddling and indicate sex-specific movement profiles, encouraging coaches to adopt individualized training strategies.