Time-Loss Injuries in Karate: A Prospective Cohort Study of 4 Consecutive World Karate Championships

BACKGROUND: Prospective studies on injuries in martial arts competitions are scarce, especially those involving time-loss injuries. The upsurge of karate athletes competing in top-level karate competitions warrants elucidation of the time-loss injury risk. PURPOSE: To determine the time-loss injury proportion and incidence rate, describe the injury pattern among elite senior karate athletes, and compare the risk of time-loss injuries in male versus female athletes and in individual (ie, weight categories) versus team competitions (free-weight category). STUDY DESIGN: Descriptive epidemiology study. METHODS: Data were collected at 4 consecutive World Karate Championships (2010, 2012, 2014, and 2016). Injury incidence rates were calculated per 1000 athlete-exposures (IIR(AE)) and per 1000 minutes of exposure (IIR(ME)), with 95% CIs. Subgroups were compared by calculating their rate ratios with 95% CIs. RESULTS: A total of 506 injuries were recorded, of which 51 were time-loss injuries (10%). The overall time-loss injury rate was significantly lower for female versus male athletes and slightly lower for team versus individual competitions. Overall, 1.4% of all athletes sustained a time-loss injury, and the IIR(AE) and IIR(ME) were 5.13 (95% CI, 3.82-6.74) and 1.98 (95% CI, 1.47-2.60), respectively. The most common type of time-loss injury was fracture (41%), followed by dislocation (20%) and concussion (12%). CONCLUSION: The time-loss injury incidence rate for top-level karate competitions found in this prospective study was relatively low. Comprehensive knowledge about the incidence of time-loss injuries during karate competitions represents an essential basis to develop effective strategies for injury prevention. Thus, the introduction of a uniform injury surveillance system in martial arts is of utmost importance.