Background Female basketball players are at a higher risk of anterior cruciate ligament (ACL) injury than male players. Therefore, prevention of ACL injury in the former group is essential.

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

Design Prospective intervention study.

Setting Top-level league in Japan.

Participants Players from 12 top-league teams. The control season (2006–2007) included 158 players; the first intervention season (2007–2008), 168 players; the second intervention season (2008–2009), 174 players; and the third intervention season (2009–2010), 162 players.

Interventions From the middle of the 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 Number and rate of ACL injuries during the four seasons and compliance with the program. Injury incidences were given in terms of per 1000 player-hours (PH).

Results Seven non-contact ACL injuries were noted during the control season (0.059/1000 PH); 4, during the first intervention season (0.031/1000 PH); 10, during the second intervention season (0.073/1000 PH); and 2, during the third intervention season (0.016/1000 PH). During the second intervention season, the rate of ACL injuries in the teams that complied with the program was 0.053/1000 PH, while the rate in the teams that did not comply was 0.099/1000 PH. During the third intervention season, the rate of ACL injuries in the teams that complied was 0.011/1000 PH, while the rate in the teams that did not comply was 0.032/1000 PH.

Conclusion The results show that the injury prevention program tended to decrease the frequency of ACL injuries.