400 Section - Evaluation of low back pain risk in elite kitesurf athletes: an electromyography Study

Objectives : Kitesurfing is a popular extreme sport with high injury rates, especially in Big Air and Freestyle. Besides acute trauma, chronic low back pain (LBP) is frequent and may be related to lumbar loading from the harness. We aimed to estimate LBP prevalence in elite kitesurfers and explore its relationship with flexion–relaxation pattern, anthropometry and discipline, particularly Big Air.

Design: We performed a cross-sectional study in elite kitesurfers. An anamnestic questionnaire recorded anthropometrics, main discipline and LBP; disability was measured with the Oswestry Disability Index. Surface electromyography and inertial sensors were used before and after one open-water kitesurfing session. The Flexion–Relaxation protocol provided the Flexion–Relaxation Ratio (FRR) as an index of LBP risk, and a Static Posture protocol assessed standing alignment.

Results: Twenty-one athletes were analysed (BMI 23.2 ± 2.8 kg/m²; age 35.0 ± 10.3 years; 11.3 ± 7 sessions/month). LBP prevalence was 41.2%, higher than in an age-matched general population. Mean FRR decreased from 10.28 ± 5.8 pre-session to 9.79 ± 2.5 post-session, suggesting increased LBP risk, although not significantly (p = 0.739). BMI correlated inversely with LBP (r = −0.862, p < 0.001) and Oswestry score (r = −0.575, p = 0.016), suggesting a protective effect of greater muscle mass. Big Air practice was strongly correlated with LBP (r = 0.998, p < 0.001), with chronic LBP more frequent in athletes performing higher jumps.

Conclusion: LBP caused by chronic overuse is common and strongly associated with Big Air, suggesting additional lumbar loading from harness traction and repeated jump–landing cycles. Targeted prevention programs focusing on core strengthening, lumbar endurance, proprioception and landing mechanics may help reduce overuse-related LBP and improve performance.