# Assessment of Injury Risk in Professional Soccer Players: A Long-Term Study
## 1 Introduction
It is innovative to analyze all four weeks (fourth, third, second, and first) before an injury in a two-year research process. The results will also show the importance (or not) of each week separately. The ratios that most frequently lead to non-contact injury, which range mainly at levels that often approach or exceed 1.3, will be notable. In a study involving 369 players, a total of 206 players (55.8%) suffered 538 lower limb injuries in two seasons [12]. However, an injury can depend on many other factors, such as lower limb muscle strength and anaerobic power, which are neuromuscular variables that affect performance in many sports activities, including soccer. This means that, if an athlete is injured, he or she loses many of the adaptations he or she had acquired through the training process, which can lead to a re-injury. In a study involving 57 soccer players, thirty-six of them were identified as having sustained a previous serious lower extremity injury. Of these 36 players, 23 (64%) still had significant muscle imbalance [13]. Our research is mainly based on the acute to chronic workload ratio (ACWR) to explain injuries. Essentially, ACWR aims to record both internal and external loads, with a primary focus on investigating data for their quantification. This research is based on findings that athletes' performance can be calculated as the difference between fitness and fatigue [14]. The acute chronic workload ratio (ACWR) is based on this research, with subsequent research data focusing on the potential relationship between ACWR and injury rather than performance [10; 15; 16; 17; 18; 19; 20]. Essentially, ACWR records the loads an athlete is subjected to in one week (acute workload) relative to the loads of the previous four weeks (chronic workload). An important factor to consider is the different positions in which soccer players compete on the field. Comparisons should be made between players who operate in similar areas of the pitch, as each position requires a specific level of fitness [21], and GPS devices typically provide relatively similar data for players in comparable positions. Excluding previous studies [22] that compare the workload of players in the same position and age group, no other research has examined this aspect in depth. Essentially, comparisons should focus on players who play in the same position. The variety of positions on the field is crucial, as each position serves a distinct tactical role, which is further supported by a study [23] examining the correlation between match performance and the running patterns of players in specific positions. Statistically, midfielders experience the highest frequency of injuries (43.6%), followed by defenders (30.0%), and forwards (17.9%), according to a relevant study [24]. GPS technology plays an important role in the assessment of external load and has been shown to help prevent injuries when this load is found to exceed certain limits established in previous weeks, especially for soccer players [22]. This is directly related to the findings of [PERSON] [25], who studied ACWR over one season in 15 high-level soccer players and suggested that, to reduce the risk of non-contact injuries, the training load should be increased gradually and an increase in acute injury could be avoided by limiting week-to-week load change (\(\geq\)9%). However, research into the relationship between load and injury is in its early stages. In this study, specific instructions will be given to manage the loads that a soccer player receives, so that he or she does not become injured. The analysis looks at all four weeks separately, which has not been thoroughly explored by existing research, and data varying from week four to week one will be presented. Thus the comparison of the microcycle that will be employed by a technical staff will be able to be compared at any time with one of the previous microcycles, knowing the limits that should not be exceeded.