# Assessment of Injury Risk in Professional Soccer Players: A Long-Term Study
## 4 Discussion  
Starting with the ACWR model analyzing the four weeks prior to injury, a statistically significant difference in the ACWR index was observed in the Distance Speed Range (15-20 km/h), Distance Speed Range (20-25 km/h), Distance Speed Range (>25 km/h), Accelerations (>2.5 m/s\({}^{2}\)), and Decelerations (>2.5 m/s\({}^{2}\)) (Table 2) (Figure 1). For the ACWR model covering the three weeks before injury, significant differences were found in Total Distance (km), Distance Speed Range (15-20 km/h), Distance Speed Range (>25 km/h), Accelerations (>2.5 m/s\({}^{2}\)), and Decelerations (>2.5 m/s\({}^{2}\)) (Table 3) (Figure 2). In the two-week ACWR model, significant differences appeared in the Distance Speed Range (15-20 km/h) and Distance Speed Range (>25 km/h) (Table 4) (Figure 3). Figure 1: Comparative data at four weeks. (#) indicates number. \begin{table}
\begin{tabular}{c c c c c c c c} \hline  & \multicolumn{6}{c}{**Injury**} \\ \cline{2-7}  & \multicolumn{2}{c}{**No**} & \multicolumn{2}{c}{**Yes**} & \multicolumn{2}{c}{**Total**} & \multicolumn{1}{c}{\(p\)**-Value**} \\ \cline{2-7}  & **Mean** & **SD** & **Mean** & **SD** & **Mean** & **SD** & \\ \hline ACWR—Total Distance (km) & 1.04 & 0.11 & 1.08 & 0.12 & 1.06 & 0.11 & 0.214 \\ \hline ACWR—Distance Speed Range (15–20 km/h) & 1.04 & 0.28 & 1.40 & 0.58 & 1.22 & 0.49 & 0.015 * \\ \hline ACWR—Distance Speed Range (20–25 km/h) & 0.98 & 0.16 & 1.08 & 0.22 & 1.03 & 0.19 & 0.126 \\ \hline ACWR—Distance Speed Range (>25 km/h) & 1.06 & 0.27 & 1.30 & 0.33 & 1.18 & 0.32 & 0.016 * \\ \hline ACWR—\# of Accelerations (>2.5 m/s\({}^{2}\)) & 1.02 & 0.14 & 1.11 & 0.13 & 1.07 & 0.14 & 0.049 * \\ \hline ACWR—\# of Decelerations (>2.5 m/s\({}^{2}\)) & 1.03 & 0.13 & 1.10 & 0.12 & 1.06 & 0.13 & 0.110 \\ \hline \end{tabular} (*) indicates statistical significance at \(p<0.05\). (#) indicates number.  
\end{table} 
Table 5: ACWR at one week. Across all models, the mean values for injured players were consistently higher than those for non-injured players. Regarding the ACWR model for the final week before injury, statistically significant differences were noted in the Distance Speed Range (15-20 km/h), Distance Speed Range (>25 km/h), and Accelerations (>2.5 m/s\({}^{2}\)), again with injured players showing higher mean values (Table 5) (Figure 4). Based on these findings, several conclusions can be drawn that offer important guidance for training management and injury prevention. Notably, ratios most associated with non-contact injuries often approached or exceeded a value of 1.3. Additionally, it was observed that in at least two of the six analyzed categories (Total Distance, 15-20 km/h, 20-25 km/h, 25-30 km/h, accelerations > 2.5 m/s\({}^{2}\), and Decelerations > 2.5 m/s\({}^{2}\)), injured soccer players showed higher loads during the week of injury compared to the preceding weeks, whether analyzed across four-week (ACWR4), three-week (ACWR3), two-week (ACWR2), or one-week (ACWR1) blocks. Figure 3: Comparative data at two weeks. (#) indicates number. Figure 2: Comparative data at three weeks. (#) indicates number. The speed parameter of 25-30 km/h appeared to play an important role when the limits were exceeded in all four-week blocks analyzed, adversely affecting an injured soccer player, which seemed to occur in conjunction with runs at speeds of 15-20 km/h, accelerations (>2.5 m/s\({}^{2}\)), as demonstrated by the research of [PERSON] [22]. In the comparative analysis, a notable discrepancy was identified in the Distance Speed Range (>25 km/h) category, with values of 1.58 over four weeks and 1.47 over two weeks for soccer players who did not experience a contact injury. In the \(p\)-value category, it is still noteworthy that, even if the four weeks recorded before an injury gave significant indications of the thresholds crossed and negatively affecting a football player, in the third and fourth weeks, this phenomenon was more pronounced for five of the six parameters, in one week for three of the five parameters, and in two weeks for two of the six parameters.