1.    Introduction
Soccer is one of the most popular sports worldwide. With its growing popularity and the increasing number of participants, the prevalence of sports-related injuries is also on the rise (1). Due to the physical nature of the sport, the risk of injury exists across all age groups and genders. Nearly 70% of soccer-related injuries affect the lower extremities, with the ankle and knee being the most commonly injured sites (2). Among knee injuries, anterior cruciate ligament (ACL) tears are among the most severe and complex, often resulting in the loss of an entire season—or, in some cases, a permanent withdrawal from the sport (3). ACL injuries can lead to decreased athletic performance, extended absence from training, joint instability, impaired proprioception, and early-onset osteoarthritis. Additionally, the financial burden of such injuries—including surgical costs, rehabilitation, and psychological impact—underscores the importance of implementing preventive strategies (5). To address this issue, various training programs have been developed to prevent ACL injuries by targeting and modifying risk factors associated with non-contact ACL injuries in athletes (6). Generally, preventive training programs for knee injuries fall into two main categories: neuromuscular training and specialized warm-up routines. These interventions typically aim to (1) modify biomechanical and neuromuscular risk factors, and (2) reduce the incidence of non-contact ACL injuries (8). Despite the critical importance of ACL injury prevention, relatively few studies have focused specifically on this topic. Therefore, the present study aims to review and evaluate the effectiveness of various preventive training protocols, with the goal of helping coaches and sports professionals select the most effective approaches to reduce ACL injury risk.
2.    Methods
This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles published between 2000 and 2025 focusing on the prevention of anterior cruciate ligament (ACL) injuries were included in the search. Relevant studies were identified using a combination of specialized English and Persian keywords, such as: prevent ACL injury, knee injury prevention, prevention of knee injuries, injury prevention in soccer, knee prevention, neuromuscular training, injury prevention programs, prevention of ACL injuries, neuromuscular intervention, as well as their Persian equivalents. Searches were performed across multiple databases, including Magiran, Medlib, ISC, SID, PubMed, Google Scholar, PEDro, Scopus, ScienceDirect, and Irandoc. Search terms were combined freely without restrictions, and reference lists of relevant articles were also manually screened to identify additional studies. Articles published in both English and Persian were considered. Following the search, titles and abstracts were screened for relevance. Studies that met the inclusion criteria were selected for review, while irrelevant articles were excluded. This process ensured a comprehensive and systematic evaluation of training protocols aimed at preventing ACL injuries in soccer players.
3.    Results
The results indicate that, out of 2,847 articles initially identified, 20 studies met the criteria for inclusion, each focusing on the prevention of ACL injuries. Of these, 19 were published in ISI-indexed journals. The selected studies were conducted on soccer players from four different countries, including 9 in Europe, 7 in the Americas, and 4 in Iran. In terms of participant demographics, 14 studies focused on female athletes, while 6 examined prevention strategies for male athletes. Regarding intervention types, 10 studies evaluated general warm-up protocols, and the other 10 investigated neuromuscular training programs. A summary of the selected studies is presented in Table 1.

4.    Conclusion
Both warm-up and neuromuscular training programs have shown success in reducing the incidence of ACL injuries. However, no single comprehensive program has yet demonstrated consistent effectiveness across all age groups and populations. A key strength of these interventions is that none have been linked to an increased risk of injury in soccer players. Nonetheless, due to the complexity of combining different types of exercises, it remains challenging to definitively determine the superiority of one approach over another. Future research should focus on developing tailored prevention programs that address the specific needs of various age groups, skill levels, and genders to improve overall effectiveness. Additionally, longitudinal studies are needed to assess the long-term impact of these programs on both injury prevention and athletic performance.

Ethical Considerations
Compliance with ethical guidelines
There were no ethical considerations to be addressed in this research.
Funding
This research did not receive any financial support from government, private, or non-profit organizations.
Authors' contributions
All authors contributed equally to preparing the article.
Conflicts of interest
The authors declare that there are no conflicts of interest associated with this article.