Seven-year prospective injury surveillance study of lateral ankle sprains in Japanese collegiate men's basketball: epidemiology and mechanisms.

OBJECTIVES: To investigate the incidence, characteristics, and injury mechanisms of lateral ankle sprain (LAS) among Japanese collegiate men's basketball players over seven competitive seasons and describe the epidemiological characteristics relevant to injury prevention. METHODS: Injury surveillance data were obtained from the Kanto Collegiate Basketball Federation across the 2018/2019 and 2024/2025 seasons (27 team-seasons). LAS were extracted from all reported injuries classified according to the International Olympic Committee consensus statement on injury surveillance. Proportional differences in injury history, contact mechanism, movement type, and time loss (days absent from participation) were analyzed. RESULTS: Of the 269 reported ankle sprains, 247 (91.8%) involved LAS. The median time loss was 6 days. Recurrent injuries accounted for 55.1% of LAS cases and resulted in a significantly longer time loss than new injuries (p = 0.022). Contact-related LAS accounted for 64% of the cases, with stepping on another player's foot being the most common mechanism (32%). Jumping was the most frequent movement-associated mechanism (35.2%), resulting in greater time loss than agility-related injuries (p = 0.023). CONCLUSION: LAS is highly prevalent among Japanese collegiate men's basketball players. The findings highlight the need for preventive strategies that address LAS and extrinsic injury mechanisms.