The effects of neuromuscular electrical stimulation on strength, pain, and function in individuals with knee osteoarthritis: a systematic review with meta-analysis

Abstract

We aimed to investigate the effects of neuromuscular electrical stimulation on muscle strength, pain relief, and improvement in function in patients with knee osteoarthritis. Databases were searched from December 2017 to July 2020 and included PubMed, Embase, LILACS, and the Cochrane Central Register of Controlled Trials. A manual search was also performed by checking the reference lists of eligible articles. The PRISMA guidelines were followed. The studies selected compared NMES with an exercise program on isometric muscle strength as a primary outcome. The secondary outcomes were pain and function. The quality of the studies was assessed using the Risk of Bias assessment and PEDro scale, and the overall quality of the evidence was assessed using the GRADE approach. Eight studies were included in this systematic review. A total of 571 patients were analyzed. Neuromuscular electrical stimulation associated with exercise promoted an increase in isometric strength of the quadriceps muscle compared to the active control group, demonstrating heterogeneity and statistical difference (95% CI=1.16 to 5.10, I2=97%, p=0.002; very low-certainty evidence). NMES associated with exercise did not improve physical function (95% CI=−0.37 to 0.59, I2=0%, p=0.67; low-certainty evidence) and showed controversial results for pain compared to an active control group (qualitative assessment). In conclusion, NMES induces an increase in muscle strength in patients with osteoarthritis compared to an active control group. No differences were found for physical function and pain outcomes. Further research is needed due to the uncertain level of evidence.

Effects of Whole-body Electromyostimulation on knee pain and physical function in adults with symptomatic knee osteoarthritis: a randomized controlled trial

“…All other studies that have investigated the effect of EMSmostly the term neuromuscular electrical stimulation (NMES) is used in literaturein knee OA have only used a local stimulation. The results of two recent meta-analysis on the effect of local EMS in individuals with knee OA indicate an increase in quadriceps muscle strength [52], but no significant reduction in pain [21,52].…”

Effectiveness of neuromuscular electrical stimulation training combined with exercise on patient‐reported outcomes measures in people with knee osteoarthritis: A systematic review and meta‐analysis

“…We aimed to investigate NMES only combined with exercise. In this sense, another systematic review found that NMES associated with exercise, compared to an active control group, increased isometric muscle strength of the quadriceps muscle in patients with knee OA, with very low‐certainty evidence (Bispo et al., 2021). Our review focused only on NMES combined with exercise, including other NMES alternatives such as superimposed on voluntary contractions and in a whole‐body configuration.…”

“…However, they have not analyzed the risk of bias. The only study that conducted such an assessment used the previous tool version (Bispo et al., 2021). Thus, one of this review's strengths is that it analyzed the risk of bias in studies based on outcomes deemed to be the most critical for decision‐making, as recommended by Cochrane (Flemyng et al., 2023).…”

“…In addition, their primary outcomes were strength and functional measurements; they did not focus on the PROMs. Prior reviews investigated NMES effectiveness on knee OA people, but their systematic search only focuses on studies with protocols involving conventional muscle application at specific articular angles; in this sense, our study investigated conventional modality and others such as whole‐body configuration and NMES superimposed muscle contractions (Bispo et al., 2021; Novak et al., 2020). A systematic review addressing the different application possibilities of NMES will increase the body of knowledge and provide alternatives for treating people with knee OA.…”

“…NMES is the most effective electrical stimulation treatment in knee OA management, and its efficiency is higher when combined with a strength exercise program (Novak et al., 2020). In a systematic review, the authors concluded with very low‐certainty evidence, that NMES combined with exercise, compared to an active control group, increased isometric muscle strength of the quadriceps femoris muscle in knee OA people (Bispo et al., 2021). However, these authors also included studies that compared NMES versus exercise, not necessarily analyzing only the effects of NMES plus exercise.…”