Reduced thoracolumbar fascia shear strain in human chronic low back pain

Abstract

BackgroundThe role played by the thoracolumbar fascia in chronic low back pain (LBP) is poorly understood. The thoracolumbar fascia is composed of dense connective tissue layers separated by layers of loose connective tissue that normally allow the dense layers to glide past one another during trunk motion. The goal of this study was to quantify shear plane motion within the thoracolumbar fascia using ultrasound elasticity imaging in human subjects with and without chronic low back pain (LBP).MethodsWe tested 121 human subjects, 50 without LBP and 71 with LBP of greater than 12 months duration. In each subject, an ultrasound cine-recording was acquired on the right and left sides of the back during passive trunk flexion using a motorized articulated table with the hinge point of the table at L4-5 and the ultrasound probe located longitudinally 2 cm lateral to the midline at the level of the L2-3 interspace. Tissue displacement within the thoracolumbar fascia was calculated using cross correlation techniques and shear strain was derived from this displacement data. Additional measures included standard range of motion and physical performance evaluations as well as ultrasound measurement of perimuscular connective tissue thickness and echogenicity.ResultsThoracolumbar fascia shear strain was reduced in the LBP group compared with the No-LBP group (56.4% ± 3.1% vs. 70.2% ± 3.6% respectively, p < .01). There was no evidence that this difference was sex-specific (group by sex interaction p = .09), although overall, males had significantly lower shear strain than females (p = .02). Significant correlations were found in male subjects between thoracolumbar fascia shear strain and the following variables: perimuscular connective tissue thickness (r = -0.45, p <.001), echogenicity (r = -0.28, p < .05), trunk flexion range of motion (r = 0.36, p < .01), trunk extension range of motion (r = 0.41, p < .01), repeated forward bend task duration (r = -0.54, p < .0001) and repeated sit-to-stand task duration (r = -0.45, p < .001).ConclusionThoracolumbar fascia shear strain was ~20% lower in human subjects with chronic low back pain. This reduction of shear plane motion may be due to abnormal trunk movement patterns and/or intrinsic connective tissue pathology. There appears to be some sex-related differences in thoracolumbar fascia shear strain that may also play a role in altered connective tissue function.

Relation Between Episiotomy and Osteomioarticular Symptoms

“…Thus, the ones with low back pain for more than one year had increased the thickness and echogenicity of the perimuscular tissue of TLF through ultrasound examination. The consequences of this tissue change can be fibrosis and tissue adhesion leading to mobility loss (Langevin et al, 2011). It is likely that from an injury in the fascia of the pelvic floor during episiotomy, there is a cause of a derangement in the bending chain tension forces (perineum, rectus abdominis).…”

Diagnostic value of musculoskeletal ultrasound in patients with low back pain – a review of the literature

“…[35,36] No No Yes [37,39,40,42] Yes [37,39,40] No No Yes [44,45] Yes [46] Yes [47] Yes [49] No No US can show structural changes in the fascia layers.…”

Anisotropic Tissue Motion Induced by Acupuncture Needling Along Intermuscular Connective Tissue Planes

“…Shear strain was calculated between the layers superficial and deep to the echolucent band separating the echogenic band closest to muscle (perimuscular fascia) and the echogenic band immediately superficial to it as previously described. 9 For each outcome measure, repeated-measures analysis of variance (SAS, PROC MIXED) was used to evaluate the significance of main effects of location (between versus over muscle) and orientation (transverse versus longitudinal) and their interaction. In order to satisfy the Gaussian distributional assumption, data were log transformed prior to analysis.…”