REPERCUSSÕES DA ESTIMULAÇÃO ELÉTRICA NOS ASPECTOS DA FUNÇÃO MUSCULAR DOS ESTABILIZADORES LOMBOPÉLVICOS EM SUBCLASSES DE DOR LOMBAR CRÔNICA

Abstract

Chronic low back pain (CLBP) is a highly prevalent global syndrome that negatively affects the functional capacity of patients. Although neuromuscular electrical stimulation (NMES) promotes muscle function optimization, its role in the rehabilitation of patients with CLBP is understudied and controversial. Thus, the overall objective of this study was to explore the repercussions induced by NMES on muscle function aspects in subclasses of volunteers with CLBP. To do so, a systematic review was conducted to investigate the effects of NMES on aspects of lumbopelvic muscle function in individuals with CLBP, and a quasi-experimental counterbalanced study was carried out to explore the immediate adjustments of different NMES currents at the point of maximum self-reported supported intensity (MSSI) in the changes of multifidus muscle (MU) thickness in subclasses of individuals with CLBP. The systematic review utilized 10 databases for the search, using a comprehensive combination of descriptors that addressed the research question. We concluded that NMES had positive effects on optimizing aspects of muscle function in individuals with chronic low back pain. However, the methods employed were highly heterogeneous, which precluded quantitative analysis. To explore the immediate adjustments of NMES, 40 volunteers, both without low back pain and with a clinical diagnosis of CLBP stratified by risk of poor prognosis (low, medium, and high risk), were exposed to four NMES modalities: two medium-frequency currents, such as Aussie current (CA) and Russian current (CR), and one low-frequency current, functional electrical stimulation (FES), with two different phase durations. They were evaluated for maximum self reported supported intensity (MSSI), changes in MU muscle thickness, and discomfort level related to the currents. The results showed no significant differences between low and medium-frequency currents; however, the MSSI of CA was lower than that of the FES currents. There was no effect on muscle thickness, and maximum voluntary contraction was superior to NMES. We concluded that patient-reported MSSI is capable of inducing an increase in MU muscle thickness, with no difference in the risk of poor prognosis for CLBP, but remaining below maximum voluntary contraction. Based on the findings of the two articles produced, we observed that NMES has the potential to induce changes in muscle function aspects, although dosimetric parameters still pose a problem to be resolved.