## 4 Discussion  
The aim of the present study was to assess the relationship between the two movement screening tools (FMS and HLLMS) in youth football players. This study found that out of all asymmetrical tasks: (1) two pairs of tasks were moderately correlated (FMS trunk rotary stability was correlated with the HLLMS SKB with trunk rotation), (2) two HLLMS tasks (standing hip flexion and hip abduction with lateral rotation) were weakly related with one FMS task (hurdle step), and (3) four FMS tasks (in-line lunge, active straight-leg raise, and shoulder mobility) and one HLLMS task (SKB) were not related. Of the symmetrical tasks, only the deep squat from FMS was moderately correlated with the deep squat from HLLMS. Analyses of total scores for the two assessment tools found that FMS total score and FMSMOVE score were moderately correlated with the HLLMS total score. Thus, our preliminary hypothesis that the relationship between the FMS and the HLLMS should be weak or even absent was not fully achieved. However, (a) most (four out of seven) FMS tasks were not related to the HLLMS at all (three asymmetrical and one symmetrical) and (b) the moderate relationship between both screening tools was caused directly by two pairings between asymmetrical trunk rotary stability (FMS) and the SKB with trunk rotation (HLLMS) as well as the symmetrical deep squat tasks from the two assessment tools. Although the deep squat was analyzed in different ways by the FMS and the HLLMS (different factors were assessed), a moderate relationship should not be surprising. Movement screening tests are generally intended to assess the movement quality and performance, and to detect altered movement patterns. It could therefore be expected that when performing the same movement task (deep squat), similar outcomes will be reached. While the criteria used may differ between the two tests, the overall movement outcome is similar. As an example, if the thigh (femur) fails to reach horizontal with the floor during the HLLMS deep squat protocol, it will be highly possible that the deep squat movement contains compensation/imperfection according to the FMS protocol. In turn, the rotatory stability test (FMS) requires multi-plane stability of the trunk in conjunction with synchronized motion of the upper and lower extremities [6; 7]. [PERSON] et al. [28] demonstrated that athletes with compensation/imperfection during the rotatory stability FMS task present reduced control of the trunk, pelvis, and hip muscles. A review of the biomechanical and clinical studies indicated that impaired muscular control of the hip, pelvis, and trunk can affect joint mechanics in the lower kinetic chain [1], triggering injuries such as anterior cruciate ligament tears [2], iliotibial band syndrome [29], and patellofemoral joint pain [3; 30]. In addition, movement disorders exist in people with femoroacetabular impingement syndrome [13; 31; 32; 33; 34; 35] and patellofemoral pain [36; 37]. The SKB with trunk rotation (the HLLMS task) is described as a test assessing relative stiffness (restrictions) [38] of thoracolumbar rotation under proper pelvic control, and evaluating the \begin{table}
\begin{tabular}{c c c} \hline \hline  & & \multicolumn{2}{c}{**HIP AND LOWER LIME MOVEMENT SCREEN**} \\ \cline{3-3}  & & \multicolumn{2}{c}{**Deep Squat**} \\ \hline \multirow{4}{*}{**Symmetric**} & & Deep squat & R = \(-0.46\) \\  & & \(p\) = 0.003 * \\ \cline{2-3}  & & Trunk & R = 0.15 \\ \cline{1-1}  & stability & \(p\) = 0.34 \\ \cline{1-1}  & push-up & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Spearman correlation for symmetrical tasks. ability to actively dissociate and control hip rotation independently of trunk rotation [39]. Thus, the rotatory stability test (FMS) and the SKB with trunk rotation (the HLLMS) are intended to detect altered movement quality caused by impaired control in the pelvic region. This may explain the moderate relationship between both the FMS and HLLMS tasks.