Load Analysis of Kitesurfing Jumps Is Kite Position Rather Than Jump Height More Crucial for Landing Impact Protection?

Background In kitesurfing, acute and overuse injuries are caused by high-impact loads, acceleration loads, and tensile loads, primarily affecting the lower extremities. Purpose To determine the specific differences in jump and landing loads on the lower extremities within the 2 kitesurfing subdisciplines "Big Air" and "Freestyle." Study Design Descriptive laboratory study. Methods Six Big Air kitesurfers (mean±SD age, 24±1.7 years) and 6 Freestyle kitesurfers (24.5±3.6 years) were recruited. Jump height, airtime, landing acceleration, and maximal vertical ground-reaction force on both feet soles during take-off and landing were determined using sensor insoles (Moticon ReGo AG) and an altitude and acceleration sensor (WOO Sports). The performed jumps were divided into 2 further subgroups based on their maneuver characteristics. Freestyle was divided into "moderate" and "aggressive", while Big Air was divided into "kiteloop successful" and "kiteloop failed." P values < .05 were considered significant. Either a one-way ANOVA or a Kruskal-Wallis test was used, followed by Holm-Sidak or Dunn's post hoc analysis. Results In Freestyle (n=6), the moderate subgroup compared with the aggressive subgroup achieved a significantly higher mean jump height ( (1.9±0.5 m vs 1.6±0.3 m; P=.02), while the aggressive subgroup achieved a significantly greater mean landing acceleration (5.3±1.1 g vs 4.5±1.2 g; P=.01). In Big Air (n=6) the kiteloop successful subgroup achieved significantly higher mean jump height values than kiteloop failed ( 5.6±2.4 m vs 4.2±0.8 m; P=.009) and significantly lower landing mean load (front, 17.92±9.39 N vs 30.97±8.49 N, P<.001; rear, 21.76±10.43 N vs 34.20±9.64 f N; P<.001). The 2 disciplines differed significantly between the aggressive and kiteloop successful subgroups, with the landing acceleration being lower in the latter subgroup (5.3±1.1 g vs 4.2±1.3; g; P=.008). On the other hand, the landing acceleration was significantly higher in the kiteloop failed subgroup than in the moderate subgroup (5.5±1.7 g vs 4.5±1.2 g P=.045). The kiteloop successful subgroup showed highly significant lower loads on both feet during landing than both subgroups of the freestyle discipline (kiteloop successful vs moderate: front, 17.92±9.39 N vs 28.84±18.22 N, P=.003 rear, 21.76±10.43 N vs 32.30±13.90 N, P < .001) (kiteloop successful vs aggressive: front, 17.92±9.39 N vs 31.99±18.25 ′ N, P<.001 rear, 21.76±10.43 N vs 35.15 ±13.27 Λ, P<.001). Conclusion Our study demonstrated that particularly during aggressive Freestyle jumps and failed kiteloop Big Air jumps, significant mechanical loading of the lower extremities was observed. In the Big Air subdiscipline, this mainly results from a missing parachute effect of the kite, which normally guarantees a protective role in high jumps with successful kiteloops. Clinical Relevance High mechanical loading during kitesurfing, especially with the aggressive freestyle riding style and failed kiteloop maneuvers, may be the cause of acute and overuse sports injuries and need to be considered in the future development of prevention concepts.