Mechanical Changes of the Lumbar Intervertebral Space and Lordotic Angle Caused by Posterior-to-Anterior Traction Using a Spinal Thermal Massage Device in Healthy People

Abstract

Background: The axial (horizontal) traction approach has been traditionally used for treatment of low back pain-related spinal disorders such as nuclear protrusion, primary posterolateral root pain, and lower thoracic disc herniation; however, it is known to have some technical limitations due to reductions of the spinal curve. Lumbar lordosis plays a pivotal function in maintaining sagittal balance. Recently, vertical traction and combination traction have been attracting attention due to improving therapeutic outcomes, although evidence of their clinical application is rare; therefore, this study was conducted to investigate the mechanical changes of lumbar intervertebral space, lordotic angle, and the central spinal canal area through vertical traction treatment using a spinal massage device in healthy participants. Methods: In total, 10 healthy subjects with no musculoskeletal disorders and no physical activity restrictions participated. The participants lay on the experimental device (CGM MB-1901) in supine extended posture and vertical traction force was applied in a posterior-to-anterior direction on the L3–4 and L4–5 lumbar sections at level 1 (baseline) and level 9 (traction mode). Magnetic resonance (MR) images were recorded directly under traction mode using the MRI scanner. The height values of the intervertebral space (anterior, center, and posterior parts) and lordosis angle of the L3–4 and L4–5 sections were measured using Image J software and the central spinal canal area (L4–5) was observed through superimposition method using the MR images. All measurement and image analyses were conducted by 2 experienced radiologists under a single-blinded method. Results: The average height values of the intervertebral space under traction mode were significantly increased in both L3–4 and L4–5 sections compared to baseline, particularly in the anterior and central parts but not in the posterior part. Cobb’s angle also showed significant increases in both L3–4 and L4–5 sections compared to baseline (p < 0.001). The central spinal canal area showed a slightly expanded feature in traction mode. Conclusions: In this pilot experiment, posterior-to-anterior vertical traction on L3–4 and L4–5 sections using a spinal massage device caused positive and significant changes based on increases of the intervertebral space height, lumbar lordosis angle, and central spinal canal area compared to the baseline condition. Our results are expected to be useful as underlying data for the clinical application of vertical traction.

Computational modeling of posteroanterior lumbar traction by an automated massage bed: predicting intervertebral disc stresses and deformation

“…In this study we performed a quantitative computational analysis of the internal stresses and strains produced in the lumbar intervertebral discs by a system that delivers posteroanterior traction of the spine. We tested the effect of different traction levels in four models with different BMI, and demonstrated the effectiveness of the approach to produce distraction of the lumbar discs, in agreement with changes of lordotic angle reported in human subjects using MRI [37]. Our study provides supporting evidence on the distraction effect of posteroanterior traction for all lumbar discs in different BMI subject models.…”

“…The predictions here also provide a direct substrate for observations of changes in intervertebral space [37] and the relief of internal compressive stresses via the induction of distraction stresses that counterbalance the compressive ones, which in turn can decrease lower back pain and disc compression states that precedes disc degeneration. The stress and strain levels predicted by the models in the intervertebral discs are below the reported thresholds for damage of the disc (ultimate stress = 2.94±1.05MPa and ultimate tensile strains = 21.3±2.1%) [47], consistent with the established safety of the commercial automatic massage bed system.…”

“…It is further shown that the mechanical traction delivered by this system is effective in a broad range of BMI subjects, and it is directly proportional to the set traction level of the therapy. In addition, tensile stresses produced by this device in the disc tissue can explain clinical observations using the same automatic message devices modeled here on immune status [6], autonomic function [10], inflammation[50, 51], pain [6-9, 52, 53], intervertebral space changes [37], and activate antioxidant enzymes [7].…”

“…Thus, the clinical usefulness of spinal traction to help with LBP has been unclear [33][34][35]. An alternative to axial traction has been recently investigated [35][36][37], based on posteroanterior (PA) traction or the combination of axial traction with PA traction, which aims to maintain the lumbar lordosis curvature throughout the spinal traction therapy [35,38] and reduce the intradiscal pressure [36]. Posteroanterior traction in supine posture was recently shown using MRI analysis to effectively increase the intervertebral space and lordotic angle [37].…”

Vertebral Related Diseases in Healthcare: The Role of Pain Management and Rehabilitation

“…In the elderly, given that VFF are the typical form of osteoporotic fractures, a proper management is mandatory in terms of pharmacological treatment and also of appropriate prescription of spinal orthoses in both acute and chronic VFF phase [ 36 ]. Furthermore, a vertical traction approach could counterbalance the boundaries of traditional (axial) traction treatment by preserving the physiological lumbar curve, without disproportionate stress on the posterior spinal structures [ 37 ].…”