Effects of digital-based interventions on muscular strength in adults: a systematic review, meta-analysis and meta-regression of randomized controlled trials with quality of evidence assessment

Abstract Background In the last three decades, both medical and sports science professionals have recognized the considerable potential of digital-based interventions (DBI) to enhance the health-related outcomes of their practitioners. Objectives This study aimed to investigate the effectiveness and potential moderators of DBI on measures of muscular strength. Methods Six databases (PubMed/MEDLINE, Web of Science, SportDiscus, Embase, Cochrane Register of Controlled Trials and Google Scholar) were searched for eligible studies up to June 2022. The GRADE, PEDRO, and TIDieR checklists were used to assess the quality of evidence, methodology, and completeness of intervention descriptions, respectively. Results A total of 56 studies were included in the meta-analysis (n = 2346), and participants were classified as healthy (n = 918), stroke survivors (n = 572), diagnosed with other neurological disorders (n = 683), and frail (n = 173). The DBI showed a small effect (standardized mean difference [SMD] = 0.28, 95% CI 0.21 to 0.31; p < 0.001) on strength, regardless of the type of intervention, control group, or tested body part. More specifically, while splitting the studies into different subgroups, a meta-analysis of 19 studies (n = 918) showed a small effect (SMD = 0.38, 95% CI 0.12 to 0.63; p = 0.003) on strength in the asymptomatic population. Similarly, small but positive effects of DBI were observed for stroke survivors (SMD = 0.34, 95% CI 0.13 to 0.56; p = 0.002), patients diagnosed with other neurological disorders (SMD = 0.17, 95% CI 0.03 to 0.32; p = 0.021), and the frail population (SMD = 0.25, 95% CI 0.0 to 0.5; p = 0.051). Sub-group analysis and meta-regression revealed that neither variable modified the effects of the DBI on measures of strength. Conclusions Overall, DBI may serve as an effective method to improve measures of strength in adults, regardless of their health status as well as the type of digital device, the presence of human-computer interaction, and the age of participants. In addition, the DBI was found to be more effective than traditional training or rehabilitation methods. KEY MESSAGES Digital-based intervention (DBI) is effective in improving measures of muscular strength in adults regardless of participants’ health status DBIs were equally effective for strength improvements in lower and upper limbs Although, DBIs were found to be effective in improving muscular strength, most studies did not follow strength training guidelines when prescribing the interventions