Electrical Properties of Lumbar Paraspinal Muscles in Young Adults With and Without Chronic Low Back Pain Based on Electrical Impedance Myography: A Cross-Sectional Study

Abstract

BackgroundLumbar paraspinal muscle (LPM) is important in spinal stabilization in patients with chronic low back pain (CLBP). However, the electrical properties of LPM in patients with CLBP remain unclear. Electrical impedance myography (EIM) is a novel and non-invasive technique that provides a simple quantitative evaluation of electrical properties of the LPM.PurposeThis study aimed to apply EIM to assess the electrical properties of the LPM between patients with CLBP and healthy control (HC).MethodsThirty participants (15 CLBP participants; 15 healthy controls) were enrolled in the study. Participants in the CLBP group were asked to complete the visual analog scale (VAS), Oswestry Disability Index (ODI), and Roland–Morris Disability Questionnaire (RDQ) to assess the pain intensity and disability in daily life. Independent sample t-tests were adopted to analyze the basic characteristics between the two groups. At 5, 50, 100, and 200 kHz current frequencies, the electrical properties were measured on each side of the LPM. The EIM parameters of resistance (R), reactance (X), phase angle (PA), and Z value were analyzed by one-way analysis of variance (ANOVA), with age as covariate. Spearman's rank correlation coefficient analysis was applied to explore the relationships between the questionnaires and the EIM parameters.ResultsThe R and Z values of bilateral LPM in the CLBP group were significantly larger than those in the HC group; the PA decreased and the X did not change at these four tested current frequencies. At 5 kHz, Z and R on the right side were non-significantly different between patients and HCs. Correlation analysis showed that at 50 kHz, ODI and RDQ scores correlated negatively with the R of the bilateral LPM (r = 0.523, r = 0.581, respectively; p < 0.05). RDQ scores correlated positively with the PA of the right LPM (r = 0.521, p < 0.05).ConclusionThe electrical properties of the bilateral LPM differed between CLBP participants and healthy individuals, regardless of the different frequencies used. These altered electrical properties of the LPM in the patients with CLBP correlated to some extent with disability in daily life.

Assessing paraspinal muscle atrophy with electrical impedance myography: Limitations and insights

“…The skin over the lumbar region was prepped with an alcohol swab and left to dry to ensure optimal adherence of the single‐use, single‐tab electrodes. The electrode placement locations were uniform for all patients, following a previously described paraspinal electrode configuration, as shown in Figure 1 17 . Patients were instructed to remain still throughout the assessment and any direct contact with metal was avoided.…”

“…| 2073 placement locations were uniform for all patients, following a previously described paraspinal electrode configuration, as shown in Figure 1. 17 Patients were instructed to remain still throughout the assessment and any direct contact with metal was avoided. The assessment was performed three times consecutively on the both sides.…”

“…One study found that the EIM readings varied significantly between patients with chronic low back back pain and those without. 17 Meanwhile, another study reported only a weak correlation between the semiquantitative grading of PMA on MRI and the fat percentage and muscle quality estimates by a commercial EIM device. 18 Thus, the relationship between the EIM readings at different frequencies with quantitative measurements of PMA on MRI scans, such as the functional cross-sectional area (fCSA) and fatty infiltration (FI), is unclear.…”

“…While EIM is increasingly utilized for monitoring atrophy of the extremity muscles in neuromuscular disorders such as amyotrophic lateral sclerosis, spinal muscular atrophy, and Duchenne muscular dystrophy, 16 little has been reported regarding its use in patients with PMA. One study found that the EIM readings varied significantly between patients with chronic low back back pain and those without 17 . Meanwhile, another study reported only a weak correlation between the semiquantitative grading of PMA on MRI and the fat percentage and muscle quality estimates by a commercial EIM device 18 .…”

Effect Analysis of Wearing an Lumbar Exoskeleton on Coordinated Activities of the Low Back Muscles Using sEMG Topographic Maps

“…The lumbar sEMG topographic map during these lumbar movements should be explored in the future. Thirdly, additional measurements of the low back muscles (e.g., muscle force, muscle thickness, muscle electrical impedance) should be explored in future studies [49][50][51], since there was no observed difference in muscle activation with and without a powered exoskeleton. Finally, the muscle fatigue state in this study is activated only in the holding task.…”