## 2 Materials and Methods
### Participants  
The initial sample consisted of 280 patients who started the postoperative physiotherapeutic procedure after ACLR in the physiotherapy center where the study was conducted between 2006 and 2017.  
Based on the medical documentation of the patients gathered in the physiotherapy center where the study was conducted, we telephonically invited 120 male patients at least one year after primary unilateral ACLR with the use of autologous ipsilateral semitendinosus and gracilis muscles tendons graft, to participate in the examination. All of the selected patients were well trained and frequently sporting pre-ACL injury. The algorithm for selecting patients for the examined group is presented in the flowchart of the study (Figure 1). Therefore, 38 ACL-reconstructed patients were included in the final study sample. Additionally, a control group including 38 healthy, well-trained, and frequently sporting males, matched in terms of gender, age, body mass, and body height, were selected from the volunteers. The characteristics of the studied participants are presented in Table 1.  
Figure 1: Flowchart of the study; ACLR: anterior cruciate ligament reconstruction; \(n\), number of individuals.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**ACL-Reconstructed Patients**} \\ \hline
**Studied Feature** & \begin{tabular}{c} **Total Number of** \\ **ACL-Reconstructed** \\ **Patients (\(n=38\))** \\ \end{tabular} & \begin{tabular}{c} **Physotherapy** \\ **Supersion \(\in\) 6 Months** \\ **(\(n=17\))** \\ \end{tabular} & \begin{tabular}{c} **Physotherapy \(\in\) 38** \\ **(\(n=21\))** \\ \end{tabular} & \begin{tabular}{c} **Control Group (\(n=38\))** \\ **(\(n=21\))** \\ \end{tabular} & \begin{tabular}{c} **_P_** \\ **(\(n=21\))** \\ \end{tabular} \\ \hline Age (years) & 29.71 (26.98, 32.44) & 30.24 (27.13, 33.34) & 29.29 (24.78, 33.79) & 26.16 (24.87, 27.45) & 0.061 \\ Body mass (kg) & 79.95 (76.41, 83.48) & 81.06 (75.42, 87.60) & 79.05 (74.91, 83.18) & 78.84 (75.89, 81.80) & 0.735 \\ Body high (cm) & 179.95 (77.97, 28.12) & 178.24 (75.04, 181.43) & 181.33 (178.25, 184.42) & 182.82 (180.66, 184.97) & 0.062 \\ Time between injury and ACLR (days) & 32.42 (13.86, 50.98) & 34.12 (2.89, 71.13) & 31.05 (12.00, 50.09) & \
\begin{tabular}{c} \(n=3\) \\ **(\(n=38\))** \\ \end{tabular} &
\begin{tabular}{c} **0.870** \\ **(\(n=38\))** \\ \end{tabular} \\ \hline Physotherapy supervision (weeks) & 23.32 (19.94, 26.69) & 15.35 (12.58, 18.13) & 29.76 (25.85, 33.68) & n/a & \textless{}0.001 \\ Follow-up (weeks) & 103.18 (90.14, 116.23) & 113.59 (92.41, 134.76) & 94.76 (77.8, 11.75) & n/a & 0.148 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Characteristics of studied participants; ACL: anterior cruciate ligament; ACLR: anterior cruciate ligament reconstruction; \(n\): number of individuals; n/a: not applicable; \(p\): level of statistical significance of the difference between patients with postoperative physiotherapy supervision \(<6\) months and patients with postoperative physiotherapy supervision \(\geq 6\) months, and control group; vGRF BM: vertical ground reaction force normalized to body mass. Values are expressed as the arithmetic mean and 95% confidence interval.