Background Female basketball players are at a higher risk for injuries such as those of the anterior cruciate ligament (ACL). Therefore, preventing such injuries is essential for their health and the competition.

Objective To assess the effect of an injury prevention training program on the incidence of injuries in female basketball players.

Design Prospective intervention study.

Setting Top-level basketball league in Japan.

Participants A total of 1127 players from 12 top-league teams during 7 seasons.

Interventions From the middle of the second (2007–2008) season, a 3-step injury prevention program was initiated. The program focused on strength, balance, jump-landing techniques, and basketball skills. Subjects were instructed to perform exercises in a neutral position and to avoid lumbar lordosis, rear axial weight bearing, hip adduction, and knee valgus.

Main outcome measurements All injuries, including ACL injury and ankle sprain, occurring during the 7 seasons that caused a player to miss a current session and/or miss a subsequent session were recorded. Injury incidences were calculated in terms of per 1000 player hours (PH). Compliance with the program was also reported.

Results During 7 seasons, 8,73,084 PH and 973 injuries were reported. The injury incidence was 1.11/1000 PH, which did not significantly change after the intervention. In each season, ankle or knee injuries were most frequent. 34 non-contact ACL injuries occurred, an incidence of 0.039/1000 PH. During 5 seasons after the intervention, the incidence of non-contact ACL injuries in the team conducting the prevention program was 0.032, while the team without the program had an incidence of 0.046. A total of 235 ankle sprains occurred, an incidence of 0.269/1000 PH. After the intervention, the incidence decreased to 0.19 in the 2011–2012 season.

Conclusions The results show that the injury prevention program may decrease the frequency of non-contact ACL injuries and ankle sprains.