Immediate and Mid-Long-Term Effects of Foot Orthoses on Gait Biomechanics and Clinical Characteristics in Medial Knee Osteoarthritis: A Systematic Review and Meta-analysis

Purpose To systematically review and meta-analyze the literature evaluating the biomechanical and clinical efficacies of foot orthoses for medial tibiofemoral osteoarthritis (TF-OA). Methods Through using the PubMed and Scopus databases, the scientific manuscripts were identified, screened, and classified. Quality of the included articles was evaluated. Where possible, meta-analyses were performed on the peak knee adduction moment (KAM), knee adduction angular impulse (KAAI), pain, function scores, and gait speed. Effect sizes were calculated as standardized mean differences with 95% confidence intervals. Pooled standard mean differences (SMDs) were calculated using a fixed-effects model; when substantial heterogeneity was detected ( I 2 ≥ 50%), a random-effects model was applied. Results Ninety-two original research articles were included, and categorized into Lateral Wedge Insoles (LWI) , Variable Stiffness Shoes (VSS) , Hybrid (LWI + VSS) , AposTherapy , Ankle-Foot Orthoses (AFOs) , and Others groups. Only LWIs with moderate inclinations (5–10°) showed significant small-to-moderate reductions in the 1 st peak KAM during both immediate responses and mid-long-term follow-ups, significant moderate-to-large mid-long-term improvements in knee pain, function, and gait speed. LWIs with low inclinations (≤ 5°) showed significant small immediate reductions in the 2 nd peak KAM and KAAI and significant small mid-long-term improvements in knee pain and function. AFOs and AposTherapy shoes demonstrated significant large clinical benefits after mid-long-term interventions. VSSs exhibited immediate biomechanical efficacy in reducing the 1 st peak KAM. Conclusion LWIs with moderate inclinations may be most effective for medial TF-OA. More studies are needed to clarify the effects of AposTherapy shoes, AFOs, and VSSs. Adaptation training with newly prescribed orthoses may enhance biomechanical and clinical outcomes. PROSPERO registration number CRD420251240304.