## 3 Results
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Total Sample** & **Patients with LBP** & **Asymptomatic Controls** & **Between-Group** \\  & **(\(n\) = 3S)** & **(\(n\) = 3S)** & **(\(n\) = 15)** & **Differences** \\ \hline  & \multicolumn{3}{c}{Demographics} \\ \hline Males, \% & 34.5 & 38.0 & 33.3 & \(p\) = 0.609 \\ Age, y & 53.7 \(\pm\) 8.5 & 53.8 \(\pm\) 9.2 & 53.7 \(\pm\) 6.5 & 0.0 (\(-\) 5.2; 5.2) \\  & \(p\) = 0.983 \\ Height, m & 1.63 \(\pm\) 0.11 & 1.64 \(\pm\) 0.11 & 1.63 \(\pm\) 0.07 & 0.01 (\(-\) 0.05; 0.06) \\ Weight, kg & 73.1 \(\pm\) 19.4 & 76.7 \(\pm\) 21.2 & 64.0 \(\pm\) 9.2 & 12.7 (\(-\) 12.2; 24.2) \\ BMI, kg/m\({}^{2}\) & 27.1 \(\pm\) 6.2 & 28.4 \(\pm\) 6.7 & 23.9 \(\pm\) 3.0 & 4.4 (0.8; 8.0) \(p\) = 0.017 \\ \hline  & \multicolumn{3}{c}{Hip flexion angle during SLR} \\ \hline Mean, \({}^{\circ}\) & 67.6 \(\pm\) 15.7 & 61.9 \(\pm\) 13.7 & 82.2 \(\pm\) 10.2 & 20.3 (14.8; 25.7) \\ Symptomatic (dominant) & 66.6 \(\pm\) 15.9 & 60.6 \(\pm\) 13.7 & 81.7 \(\pm\) 10.0 & 21.0 (13.2; 28.8) \\  & \multicolumn{3}{c}{} & \multicolumn{3}{c}{} & \multicolumn{1}{c}{} \\ Non-symptomatic (non-dominant) side, \({}^{\circ}\) & 68.7 \(\pm\) 15.6 & 63.2 \(\pm\) 13.7 & 82.7 \(\pm\) 10.8 & 19.5 (11.6; 27.5) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Descriptive demographic and clinical information of the samples assessed. Figure 3: Histograms of hip flexion angle measurement. Vertical axis represents frequency, horizontal axis represents mean. Black line represents the normality curve. (**A**) LBP, both sides; (**B**) asymptomatic controls, both sides; (**C**) LBP, symptomatic side; (**D**) asymptomatic controls, dominant side; (**E**) LBP, non-symptomatic side; (**F**) asymptomatic controls, non-dominant side. the scores obtained by the experienced examiner did not differ significantly between trials (\(p\) = 0.924 for patients with LBP and \(p\) = 0.930 for asymptomatic controls). The absolute error was low across all conditions, ranging from 0.8\({}^{\circ}\) to 1.0\({}^{\circ}\), indicating minimal variation between trials for the same examiner. ICC\({}_{3,1}\) scores were exceptionally high (0.995-0.998), reflecting excellent reliability in the repeated measurements performed by both novel and experienced examiners. SEM scores were small in accordance with the ICCs obtained, ranging from 0.5\({}^{\circ}\) to 0.7\({}^{\circ}\), further supporting the precision of the measurements. Finally, MDC at 95% confidence ranged from 1.3\({}^{\circ}\) to 1.9\({}^{\circ}\), highlighting the test's sensitivity to detect true changes in hip flexion angle. Therefore, the overall results demonstrated excellent intra-examiner reliability for hip flexion angle measurements during the SLR test, irrespective of examiner experience. The inter-examiner reliability estimates of Kinovea for hip flexion angle measurement during the SLR test are summarized in Table 3. Analyses were conducted separately for the patients with LBP and the asymptomatic controls and considering single measurements and a mean average of two measurements. The results indicated no significant differences between the examiners using a single measurement in the patients with LBP (\(p\) = 0.484) or the asymptomatic controls (\(p\) = 0.581). Similarly, the mean differences obtained by each examiner calculating a mean average of two measurements were comparable as were not significant (\(p\) = 0.638 for patients with LBP and \(p\) = 0.618 for asymptomatic controls). Absolute errors for inter-examiner comparisons were low across both groups and conditions, suggesting minimal discrepancies between the examiners. The ICC\({}_{3,2}\) scores demonstrated excellent reliability across all conditions, ranging from 0.985 to 0.992. For single measurements, ICC values were 0.989 for patients with LBP and 0.985 for asymptomatic controls. When using the mean average of two measurements, ICC values slightly improved, reaching 0.992 for patients with LBP and 0.986 for asymptomatic controls.