Characteristics of High-Impact Movements Observed in High School Handball Players During Games

Background In handball, injury occurs more frequently during actual games than during handball practice. However, mechanical loading during actual games is unknown. Purpose The purpose of this study was to describe body impact characteristics during handball games using accelerometers, and to investigate sex differences in these characteristics. Study Design Comparative observational study. Methods Acceleration data were measured during practice games in 24 high school handball players (12 males, 12 females). The acceleration was set to 1 gravitational acceleration (G) when each axis direction was aligned with the direction of gravity during data collection. High-impact movements with a resultant acceleration of ≥ 6G were extracted, and video images was used to identify movements and plays during which the high-impact movements occurred. The number of cases, percentage, frequency (cases/min ･ person), and 95% confidence interval of the frequency were calculated for the movement classification, play classification, and movement classification × play classification. The peak acceleration values of resultant accelerations of ≥ 6G were also obtained. Results The frequencies of resultant acceleration ≥ 6G were 5.3 cases/min ･ person for males and 4.7 cases/min ･ person for females. Deceleration and sprinting were the most frequent motion categories in both sexes. High-impact movements were more frequent in fast attack-related play in males and attack-to-defense transitions in females. Conclusion High-impact movements are more frequent in plays related to fast attacks in males and when switching from attack to defense in females. High-impact movements are more likely to occur during the switch from attack to defense in females. Level of evidence 3