Neuromuscular electrical stimulation for muscle strengthening in elderly with knee osteoarthritis e A systematic review Mônica de Oliveira Melo a, d, * , Fernando Amâncio Aragão a, b , Marco Aurélio Vaz a, c a Exercise Research Laboratory, School of Physical Education, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil b Faculty of Physical Therapy, State University of West Paraná, Cascavel, PR, Brazil c Physique Centre of Physical Therapy and Physical Fitness, Porto Alegre, RS, Brazil d University of Caxias do Sul, Caxias do Sul, RS, Brazil Keywords: NMES Knee osteoarthritis Elderly Strengthening abstract Purpose: To identify if there is evidence in favor of the use of NMES to quadriceps muscle strengthening in elderly with knee OA. Data sources and study selection: A search of PubMed/Medline, PEDro and Cochrane Library produced a total of 76 relevant trials. Six studies that met the inclusion criteria were selected for this review. Data extraction: Trials were addressed by inclusion and exclusion criteria and scoring internal validity using PEDro scale. Data syntheses: A summary of the sample and design characteristics, and muscle strength results from each study were presented on table. Conclusion: The best-evidence analysis showed moderate evidence in favor of NMES alone or combined with exercise for isometric quadriceps strengthening in elderly with OA. In addition, for the effects of NMES intervention as an adjunct therapy on isokinetic strength at different angular velocities, there was a limited quality of evidence assessed. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Knee osteoarthritis (OA) is a painful and chronic degenerative joint disease that affects nearly 27 million people in the United States. 1 Pathologic changes in OA involve progressive hyaline joint cartilage loss with concomitant changes in the subchondral bone and the development of osteophytes. 2e5 The clinical symptoms of OA often include muscle weakness, disability, stiffness, joint deformity, decreased range of motion and chronic pain. 5,6 According to Slemenda et al., 7 quadriceps muscle weakness is evident in subjects with symptomatic knee OA. In these cases, a dilemma is faced by physiotherapists when deciding the best treatment. While pharmacological treatments (paracetamol, nonsteroidal antiinflammatory drugs, and topical agents) cause numerous adverse affects, 4,8 pain can decrease the adherence to non-pharmacological therapy, such as regular quadriceps strengthening exercise. This, in turn, could lead to an increase in knee pain and a decrease in muscle strength and function. 9,10 Due to this vicious cycle (pain-weakness-pain), other non- pharmacological strategies and physical therapies have been used in the clinical practice with the aim of recovering joint function and reducing pain. Among the therapeutic modalities, neuromuscular electrical stimulation (NMES) is presented as a non-invasive technique used by physical therapists (1) to promote muscle strengthening, (2) to minimize muscle hypotrophy, (3) to reduce muscle spasm and spasticity and (4) to increase range of motion in the joint. 11e13 Particularly, with respect to knee OA treatment, NMES has been suggested as an alternative therapy for quadriceps muscle strengthening, mainly when elderly present chronic pain and joint stiffness, which prevent them from engaging in voluntary exercises. 4,9 Despite the importance of muscle strength loss attributed to disuse and/or muscular inhibition as an important factor involved in the etiology and progression of OA, 14 to the best of our knowl- edge, no systematic review has summarized the results of using NMES to achieve quadriceps strengthening in the elderly with knee OA. Considering that this information might be of use in clinical practice, the purpose of this study was to identify if there is * Corresponding author. Ave Willy Eugênio Fleck 1500, Casa 187, 90150-180 Porto Alegre, Brazil. E-mail addresses: melo.monica@terra.com.br (M. de Oliveira Melo), feraragao@ terra.com.br (F.A. Aragão), marcovaz@esef.ufrgs.br (M.A. Vaz). Contents lists available at SciVerse ScienceDirect Complementary Therapies in Clinical Practice journal homepage: www.elsevier.com/locate/ctcp 1744-3881/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ctcp.2012.09.002 Complementary Therapies in Clinical Practice 19 (2013) 27e31