## 2 Materials and Methods
### Data Synthesis and Analysis  
Data regarding leg extensor and flexor strength and thigh muscle size were extracted from studies focusing on the lower limbs; when studies addressed the upper limbs, grip and wrist flexion-extension strength and wrist and forearm muscle volumes were evaluated. Simultaneously, pain experienced by the patient during the rehabilitation process was assessed. A narrative approach to the results was conducted, and a meta-analysis was performed using RevMan 5.4, a software developed by The Cochrane Collaboration, Oxford, England. Heterogeneity between studies was assessed using the chi-square test and the I\({}^{2}\) test. The interpretation of the I\({}^{2}\) results was as follows: values greater than 75% indicated a high level of heterogeneity, while values below 40% suggested a low level of heterogeneity [38]. Considering the heterogeneity among the included studies, a random effects model was employed for the analysis. Effect sizes were assessed using the standardized mean difference (SMD). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Author and Year** & **Study Design** & **GRADE** & **Journal (JCD)** & **N** & **N (Intervention–Control)** & \\  & & & & & & and \%AOP** & **Surgery** \\ \hline [PERSON] et al., 2019 [32] & RCT & High & Sports Medicine (2.11) & 24 & 1 (LL-BER 80\% AOP n = 12) & ACL \\ [PERSON] et al., 2022 [39] & RCT & High & & Journal of Rehabilitation & 24 & 1 (LL-BER 80\% AOP n = 12) & ACL \\ [PERSON] et al., 2023 [40] & RCT & High & & Medicine (1.03) & 24 & and C (LLT n = 12) & reconstruction \\ [PERSON] et al., 2023 [40] & RCT & High & Sports Health & 32 & 1 (LL-BER 80\% AOP n = 17) & ACL \\  & & & & & and (CLT = 11)5 & reconstruction \\ [PERSON] et al., 2023 [41] & RCPT & High * & & BMC Musculoskeletal & 1 (LL-BER 80\% AOP n = 8) & ACL \\  & & & Disorders (0.77) & 23 & and 40\% AOP n = 9) and C (RT & reconstruction \\ [PERSON] et al., 2022 [42] & RCT & High & & Medicine (0.38) & 42 & and 40\%AOP n = 14) and C & High tibial \\  & & & & & (LLT = 15) & osteotomy \\ [PERSON] et al., 2022 [43] & RCT & High & Frontiers in Physiology (1.00) & 38 & 1 (LL-BER 80\% AOP n = 19) & Knee arthroscopy \\ [PERSON] et al., 2022 [44] & RCT & High * & & Journal of Sport & 1 (LLBERT 80\% AOP n = 8) & (mensional repair or \\  & & & Rehabilitation (0.92) & 17 & 1 (LL-BER 80\% AOP n = 8) & (mensional repair or \\  & & & & & & \\ [PERSON] et al., 2017 [45] & RCPT & High & & Clinical Journal of Sport & & 1 (LL-BER 80\% AOP n = 10) & \\  & & & Medicine (1.27) & 17 & and C (Protocol of Standard & Knee arthroscopy \\ [PERSON] et al., 2023 [46] & RCT & High * & Annals of Medicine (0.98) & 35 & 1 (LLBERT 40-8\% AOP n = 17) & ORF for distal \\  & & & & & n = 17) and C (LLT n = 18) & radius fracture \\ [PERSON] et al., 2020 [47] & RCT & Moderate & Journal of Wrist Surgery (0.29) & 9 & 1 (LL-BER 80\% AOP n = 5) & ORF for distal \\ [PERSON] et al., 2024 [48] & RCT & High & & Medicine and Science in & 48 & 1 (LL-BER 80\% AOP n = 23) & ACL \\  & & & Sports and Exercise & & and C (RT n = 25) & reconstruction \\ [PERSON] et al., 2022 [49] & RCT & High & Applied Sciences & 24 & 1 (LL-BER 80\% AOP n = 12) & ACL \\  & & & & & Physical Therapy n = 12) & reconstruction \\ [PERSON] et al., 2023 [50] & RCT & High & & The Orthopaedic Journal of Sport Medicine & 1 (LL-BER 80\% AOP n = 16) & ACL \\  & & & Sport Medicine & 38 & and (Standard Protocol of \\  & & & & Physical Therapy n = 22) & reconstruction \\ \hline \hline \end{tabular}  
* I: Intervention; C: Control; JCJ: Journal Citation Indicator; RCT: Randomized Controlled Trial; RCPT: Randomized Controlled Pilot Trial, LLBPRT: Low Load Blood Flow Restriction Training; HLT: High Load Training; LLT: Low Load Training; RT: Resistance Training; ACL: Anterior cruciate Lieutenant; AOP: Arterial Occlusion Pressure, ORF:Open reduction and internal fixation.
* The article presents items that can lower the initially allocated level of quality.  
\end{table} 
Table 2: Main characteristics of the included studies.