Additional Effects of Manual Therapy to Exercise on Pain and Function in Individuals With Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

Abstract

This systematic review aimed to analyse the additional effects of manual therapy (MT) to exercise (EX) compared to EX alone on pain, function, and PPT in individuals with knee osteoarthritis (KOA). Six databases (MEDLINE, PEDro, EMBASE, CENTRAL, CINAHL, and Web of Science) were searched from inception up to May 2026. Two independent reviewers selected randomized clinical trials. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated by random-effects for meta-analyses. The review was registered in PROSPERO (CRD42024525169), and the certainty of a body of evidence was classified using GRADE. Twenty-nine studies were included. MT combined with EX, compared to EX alone, reduced pain in the immediate (mean difference [MD] = -0.53; 95% CI = -0.97 to -0.09 very low certainty of evidence), short-term (MD = -1.30; 95% CI = -1.74 to -0.87 very low certainty of evidence), and medium-term (MD = -0.98; 95% CI = -1.86 to -0.10 moderate certainty of evidence). Function also improved in the short-term (SMD = -0.89; 95% CI = -1.49 to -0.29 very low certainty of evidence) and medium-term (SMD = -0.62; 95% CI = -1.13 to -0.10 very low certainty of evidence). However, no significant long-term effects were observed for either pain and function. No eligible studies assessing pressure pain threshold (PPT) were identified. An additional effect of MT to EX was observed; however, the certainty of the evidence was very low to low. MT can be considered an adjunctive intervention in KOA, as it appears to provide short-duration effects on both pain relief and functional outcomes, but does not seem to extend to the long term. This systematic review identifies that MT can be considered a complementary intervention when combined with EX, which appears to provide immediate, short- and medium-term effects, both in pain relief and functional outcomes in KOA. The use of MT with EX may assist patients at the beginning of the rehabilitation process. However, its benefits do not appear to extend to the long term, highlighting that MT can serve as a strategy to support exercise, particularly during the initial phase of treatment.