TENS reduces pain (MD -0.82) and improves muscle strength in patients with knee osteoarthritisTENS Therapy May Help Manage Knee Osteoarthritis Pain

OBJECTIVE: This systematic review and meta-analysis aimed to evaluate the effects of TENS on pain, physical function, muscle strength, stiffness, and mobility, and to examine its potential role in multimodal rehabilitation for knee osteoarthritis (KOA). METHODS: A comprehensive literature search was conducted across six databases from inception to July 2025. Meta-analyses of randomised controlled trials (RCTs) assessed the effects of TENS on KOA related pain, physical function, muscle strength, range of motion (ROM), and stiffness using random effects models, with subgroup and sensitivity analyses. RESULTS: Twenty-one RCTs were included in the review, with 20 contributing to the meta-analysis. TENS significantly improved pain [mean difference (MD) = -0.82, 95% confidence interval (CI): -1.01 to -0.62], total WOMAC scores (MD = -4.76, 95% CI: -8.84 to -0.67), and muscle strength in knee extension (MD = 7.39, 95% CI: 0.91 to 13.88) and flexion (MD = 4.72, 95% CI: 1.92 to 7.52). No significant effects were observed for stiffness, range of motion (ROM), or the 6-min walk test (6MWT). Heterogeneity was observed across studies, partly explained by variations in TENS parameters and comparator interventions. CONCLUSION: TENS effectively reduces pain and improves muscle strength in individuals with knee osteoarthritis. Improvements in overall function, as indicated by total WOMAC scores, were observed; however, effects on specific functional domains such as mobility and stiffness remain limited. Despite substantial heterogeneity and the presence of co-interventions in some studies, TENS appears promising as an adjunctive strategy within multimodal rehabilitation. Future research should focus on optimising treatment protocols and evaluating the long-term sustainability of TENS effects. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42024579013.