## 2 Prevention of NC-ACLs
### Strategies to Prevent the Occurrence of NC-ACLs
[32] determined the effectiveness of a specific warm-up routine to prevent NC-ACLs in young female soccer players. This randomized controlled trial had the intervention group follow a special 12-week warm-up program called the Prevent injury and Enhance Performance (PEP) Program during the season. The intervention group experienced a 41% reduction in NC-ACLs compared to the control group. For players who had previously undergone ACL reconstruction and completed rehabilitation, the program showed a 100% reduction in re-injury from NC-ACLs and an 80% reduction from contact injuries. [PERSON] et al. [54] demonstrated a statistically significant lower risk of ACL injuries in the intervention group that followed a specific proprioceptive training program. However, the study did not report the exact number of NC-ACLs, leaving the complete understanding of the proprioceptive training's effectiveness in preventing NC-ACLs unclear. [PERSON] et al. [55] investigated a neuromuscular training program performed over three years to prevent ACL injuries. Elite players who participated in the program had significantly fewer ACL injuries than those who did not, with a notable reduction in NC-ACLs. However, [PERSON] et al. [33] found that although the trained group had a lower percentage of ACL injuries (2.4% vs. 3.1% in the control group), the difference was not statistically significant, compromising the perceived effectiveness of the preventive program. The prospective study by [PERSON] et al. [56] evaluated the effectiveness of a Knee Ligament Injury Prevention (KLIP) program over two years among athletes in soccer, volleyball, and basketball. The KLIP program included 15 min of strengthening and pylemetric exercises. Although there was no significant difference in ACL injury rates between the intervention and control groups, there were no NC-ACLs among soccer and volleyball players in the intervention group. Intriguingly, all NC-ACLs in the intervention group (with the KIP program) affected basketball players, thus elucidating the need for training programs that should be tailored to the specific sports activity. The lack of statistically significant difference might be attributed to the relatively short duration of the program (9 weeks). Furthermore, since the experimental program was conducted after the classic training sessions, neuromuscular fatigue might have compromised the correct execution of the prevention program [56]. In their study implementing the KLIP program, [PERSON] et al. [38] reported six NC-ACLs, equally distributed among the treatment and control groups, thus resulting in a non-significant reduction in NC-ACLs [38]. [PERSON] et al. [35] conducted a study over two years on young female soccer players using a specific 20 min warm-up program that included exercises in athletic gesture education, stretching, muscle strengthening, pylemetrics, and agility. The program resulted in an 88% reduction in ACL injuries in the first year and a 74% reduction in the second year compared to the control group, highlighting its effectiveness. However, being a non-randomized prospective study with voluntary enrollment, the study may have suffered from a \"Hawthorne effect\" and selection or motivational bias, as the teams that chose to participate were likely more interested in injury prevention. Conversely, in a randomized study including 1837 players aged between 15 and 17 years, [PERSON] et al. [51] demonstrated a significant NC-ACL reduction in the experimental group after 8 months of training. Research by [PERSON] et al. [53] and [PERSON] et al. [57] focused on the Knee Injury Prevention Program (KIPP), which included a warm-up with jumping drills, balance exercises, and core strengthening. Both studies found a significant decrease in NC-ACLs in the trained groups, demonstrating that specific exercise programs can significantly reduce the incidence of these injuries. [PERSON] et al.