## 4 Discussion  
The purpose of this study was to determine if the different components of a PA involving a series of functional tests used to assess the functional capacity of football athletes could provide unique information regarding lower limb performance and core stability. The factor loadings on the dominant and non-dominant lower limb indicated that multiple measures of dynamic balance, force attenuation, and muscle activation loaded onto separate factors provide unique information and cannot be extracted from other functional tests. It deems that the stability of the knee joint during dynamic activities is influenced by the neuromuscular control of the thigh muscles, which regulates knee motion and loading. Specifically, a balanced co-contraction of the quadriceps and hannstrings in one-lower-limb landing is crucial in order to manage the loading effectively during landing [47]. EMG and kinetic data seem to provide unique information but require additional equipment and time, which may limit their application to wider field settings. Nevertheless, in the present study, there was no functional test that was highly correlated in order to replace these time-consuming measurements. Note that core stability tests along with kinetic data accounted for the greatest amount of the total variance. Although the greatest core endurance has been associated with better landing performance [38], the results of the present study support the use of both measurements for core stability and landing performance, such as prone bridge and peak VGRF. These are loaded on separate factors, suggesting the uniqueness of this information. However, as the factor \"core stability\" prone bridge was highly correlated with side bridge tests, it can be suggested that for core stability one of these two tests can be safely performed. The triple hop test was correlated with quadriceps strength on dominant lower limb, while, on the non-dominant lower limb, it was correlated with core stability. The relationship between isokinetic quadriceps strength and triple hop has been identified in previous studies [32, 48]. In the present study, a moderate relationship with quadriceps strength in the dominant lower limb and core stability with non-dominant lower limb was identified. The high loadings on abdominal endurance tests on core stability and quadriceps strength on the factor \"quadriceps performance\" support that the triple hop could be omitted by the \begin{table}
\begin{tabular}{c c c c c} \hline  & **F1 (22.19\%) Core** & **F2 (0.35\%) Dynamic** & **F3 (13.78\%)** & **F4 (10.12\%) Q-H** & **F5 (8.13\%) QD-ABD** \\  & **Stability** & **Balance** & **GRF** & **EMG Ratio** & **Strength** \\ \hline \hline Q-H EMG ratio pre-landing & & & & 0.864 \\ \hline Q-H EMG ratio post-landing & & & & 0.897 \\ \hline Peak VGRF-normalized & & & 0.973 & \\ \hline RDF & & & 0.935 & \\ \hline Total COP length & & 0.704 & 0.318 & \\ \hline COP SDx & & 0.725 & & \\ \hline COP Sdy & & 0.939 & & \\ \hline Prone bridge & 0.784 & & & \\ \hline Side bridge D & 0.869 & & & \\ \hline Side bridge ND & 0.886 & & & \\ \hline Abductors isometric & & & & 0.828 \\ \hline THD & 0.619 & & & \\ \hline Quadriceps isometric & & & & 0.848 \\ \hline \end{tabular}
\end{table} 
Table 3: Pattern matrix with factors and measured items for the non-dominant lower limb. Abbreviations: F: factors, Q-H EMG: quadriceps-hamstrings electromyography, THD: triple hop for distance, D: dominant, ND: non-dominant, VGRF: vertical ground reaction forces, COP SD: center of pressure standard deviation, RDF: rate of force development, QD: quadriceps, ABD: abductors. battery as its information is similar to the information given from the quadriceps strength and core stability tests. Finally, regarding the LESS, there are some interesting results. Note that the LESS has been used as a valid and reliable tool for the identification of high-risk biomechanical patterns for ACL injury [20].