Lumbar muscles biomechanical characteristics in young people with chronic spinal pain

Abstract

Background: The prevalence of low back pain is rising among the young adult population. Altered lumbar muscle tone was suggested to be associated with underlying pathologies and symptoms. To date, there is minimum information available on the repeatability of lumbar spine muscle mechanical properties in the young adults who experienced low back pain. This study aimed to assess the reproducibility of mechanical properties of lumbar spinal muscle in young adults with spinal pain by myotonometer and explored the difference in reproducibility when different number of indentations was used. Methods: Participants who aged between 18 to 25 and reported chronic LBP were recruited. Lumbar muscle tone (Hz) and stiffness (N/m) were assessed by myotonometer on one occasion by two assessors. Parameters were recorded by triple scans and 5-scans mode. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), smallest real difference (SRD), Bland and Altman analysis were used to assess agreement between two measurements. The relationship between muscle mechanical properties and pain score and disability level were assessed by Spearman's rank correlation coefficient. Results: The results of ICCs indicated excellent repeatability in triple scans and 5-scans mode for each lumbar level bilaterally (ICC > 0.75). SEM and SRD were smaller in triple scans than 5-scans mode for most levels. Bland and Altman analysis revealed no systematic bias. Spearman's rank correlation analysis indicated significant high correlations between muscle tone and disability level (r = 0.80, p < 0.05), and between muscle stiffness and disability level (r = 0.81, p < 0.05). Conclusions: This study found that lumbar spinal muscle tone and stiffness were repeatable parameters when measured by myotonometer. The reproducibility of muscle mechanical parameters did not appear to differ between the two scanning modes with different number of indentations. Muscle tone and stiffness measured by myotonometer may therefore be reliable as outcome measures to assess intervention induced changes. The lack of significant association between intensity of pain and mechanical properties of paraspinal muscles may suggest that muscle properties measured at rest might not be related to pain level at rest but more related to pain elicited during movement.

Paravertebral Muscle Mechanical Properties and Spinal Range of Motion in Patients with Acute Neck or Low Back Pain: A Case-Control Study

“…The mean values of lumbar musculature stiffness of young control subjects [ 28 ] and elder control subjects [ 44 ] were similar to those values obtained in the current study for all groups. Furthermore, current values of tone and stiffness were lower than those reported for other pathological populations, such as young [ 28 , 71 ] and elderly [ 44 ] individuals with chronic spinal pain, and even inflammatory pain [ 29 ]. In fact, the differences among the three groups, which did not show statistical significance, were lower than the minimum detectable change established for these variables in the lumbar muscles [ 29 ], and may be explained by the acute state of patients in our study, and the rest assessment position.…”

“…Controversial results have been reported for the association between MMPs and ROM, and pain in chronic LBP patients, with some data supporting positive correlations with tone, stiffness and decrement [ 44 ], whereas others do not [ 71 ]. As occurred with the differences among the groups, it is possible that the association between pain and MMPs only appears in the chronic state, as consequence of an interaction or confluence of various predictors such as emotional, cognitive, social and physical factors [ 39 ], as described for other musculoskeletal complaints [ 58 ], but not in the acute state.…”

The Effects of Extracorporeal Shock Wave Therapy on Spastic Muscle of the Wrist Joint in Stroke Survivors: Evidence From Neuromechanical Analysis

“…Once the required depth was reached (indicated by a change of indicator light from red to green), the device then applied three short impulses (1 s apart) to induce damped oscillations within the muscle bulk ( Figure 2B ). The oscillation pattern recorded by the transducer was used to calculate the muscle mechanical properties of tone and stiffness (Lo et al, 2017 , 2019 ).…”

Impact of nonsurgical spinal decompression on paraspinal muscle morphology and mechanical properties in young adults with low back pain

“…For muscle stiffness, the standard error measurement was 1.82 Hz on the left and 2.15 Hz on the right. 45 The participants were asked to lie in the prone position on the traction table with their hands on both sides of their head, exposing the lumbar region. The test site was determined by palpation.…”