Effects of the new karate rules on the incidence and distribution of injuries

To evaluate the incidence and distribution of injuries in karate before and after the implementation of new rules established by the World Karate Federation in 2000.

Injury incidence was followed up during the official karate competition seasons of 1997 and 2002 in Croatia. A questionnaire was used to collect data on the age and sex of the competitor and localisation and severity of injury. Data were analysed separately for female and male competitors and age categories < 18 and > or = 18 years.

A total of 2023.5 and 2584 minutes of active fighting (exposure time) was assessed for 1997 and 2002 respectively. The overall injury incidence rate (IR) was similar in 1997 and 2002 (10.28 and 9.82/100 exposure minutes respectively). The relative risk (RR) of injury was significantly higher in 1997 than in 2002 for competitors younger than 18 years (RR 1.55, 95% confidence interval (CI) 1.11 to 2.16). The overall RR of head injury was significantly higher in 1997 than in 2002 (RR 1.96, 95% CI 1.54 to 2.49), but the RR of leg injury was significantly lower in 1997 than in 2002 (RR 0.16, 95% CI 0.09 to 0.28). Most injuries (> 98%) were categorised as mild (grade 1) in both periods studied.

The results of this study confirm the importance of the new competition rules in the distribution and prevention of injuries in martial arts. Strict judging and heavy penalties for uncontrolled blows, particularly for the youngest competitors, can significantly decrease the risk of injury.