Effect of neuromuscular electrical stimulation associated with therapeutic exercise on pain, function, and strength of people with knee osteoarthritis: a systematic review with meta-analysis of randomized clinical trials with GRADE recommendations

Andressa Costa da Silva; Geovanna Cândido Rafael; Rayane Quintão Castro; Priscila Monteiro Veras; Cyntia Pace Schmitz Corrêa; Jennifer Granja Peixoto; Fabiana Roberta Nunes Carnaúba; Marco Antonio Cavalcanti Garcia; Carla Malaguti; Diogo Carvalho Felício; Diogo Simões Fonseca

doi:10.1080/09638288.2026.2633271

Effect of neuromuscular electrical stimulation associated with therapeutic exercise on pain, function, and strength of people with knee osteoarthritis: a systematic review with meta-analysis of randomized clinical trials with GRADE recommendations

Disabil Rehabil. 2026 Feb 26:1-17. doi: 10.1080/09638288.2026.2633271. Online ahead of print.

Affiliations

¹ Programa de Pós-graduação em Ciências da Reabilitação e Desempenho Físico Funcional, Faculdade de Fisioterapia, Universidade Federal de Juiz de Fora, Brazil.
² Faculdade de Fisioterapia, Universidade Federal de Juiz de Fora, Brazil.
³ Programa de Pós-graduação em Saúde, Faculdade de Medicina, Universidade Federal de Juiz de Fora, Brazil.
⁴ Hospital Universitário da Universidade Federal de Juiz de Fora/Empresa Brasileira de Serviços Hospitalares, Brazil.
⁵ Curso de Fisioterapia da Universidade Federal de São Paulo, Brazil.

PMID: 41742784
DOI: 10.1080/09638288.2026.2633271

Abstract

Objective: To determine whether NMES combined with therapeutic exercise improves pain, function, and muscle strength compared to exercise alone in adults with KOA.

Methods: We searched nine databases (PubMed, MEDLINE-Ovid, EMBASE, Cochrane Library, Web of Science, Scopus, SPORTDiscus, LILACS, SciELO) up to 5 April 2025. Randomized controlled trials comparing NMES + exercise with exercise alone were eligible. Two reviewers independently screened records, extracted data, and assessed methodological quality and risk of bias using the PEDro scale and the RoB 2. Random-effects meta-analyses generated mean differences (MD) or standardized mean differences (SMD). Certainty of the evidence was assessed with GRADE (PROSPERO CRD42023393616).

Results: Eight trials (354 participants; mean age ≈59 years; 71% women) were included. Immediately post-intervention, NMES + exercise did not reduce pain versus exercise alone (SMD -0.90, 95% CI -1.84 to 0.03; I² = 84%). At 8-12 weeks, small benefits were observed for pain (SMD -1.30, 95% CI -1.87 to -0.73; I² = 0%) and TUG (SMD -0.67, 95% CI -0.98 to -0.35). No differences were found for WOMAC total or quadriceps strength. Certainty was very low.

Conclusions: NMES + exercise may modestly improve long-term pain and mobility in KOA, though evidence certainty is very low.

Keywords: Knee osteoarthritis; function; muscle strength; neuromuscular electrical stimulation; pain; physical performance.

Plain language summary

Very low-certainty evidence suggests that adding neuromuscular electrical stimulation to therapeutic exercise may reduce pain and improve long-term physical performance (Timed Up and Go test) in individuals with knee osteoarthritis.Neuromuscular electrical stimulation combined with exercise did not improve quadriceps strength beyond exercise alone.Neuromuscular electrical stimulation combined with exercise did not improve WOMAC global function beyond exercise alone.Clinical decisions should not recommend neuromuscular electrical stimulation at this stage due to its small and uncertain effects and the lack of higher-quality evidence.

Publication types

Review