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Background: Lumbar muscle dysfunction is commonly implicated in low back pain (LBP). Shear-wave elastography (SWE) uses ultrasound technology to quantify absolute soft tissue stiffness (shear modulus), thereby allowing for estimation of individual muscle contraction and function., Objectives: To compare resting and contracted stiffness of lumbar spine musculature in individuals with and without LBP using SWE. A secondary aim was to explore for relationships between common self-report and physical examination measures and resting and contracted muscle stiffness in individuals with LBP., Design: Cross-sectional., Methods: Shear modulus of the lumbar musculature was measured in 60 participants with LBP and 60 asymptomatic controls (120 total) using SWE. The lumbar erector spinae were imaged at rest only, while the lumbar multifidus was imaged at rest and during contraction. Before imaging, participants with LBP underwent a standardized clinical examination including a brief history, self-report questionnaires, and a physical examination. Lumbar muscle shear modulus was compared between participants with LBP and asymptomatic controls using ANCOVA. Potential associations between shear modulus and selected self-report and physical examination measures were assessed using correlation analysis., Results: Stiffness of the erector spinae and lumbar multifidus at rest (but not during contraction) was greater in participants with LBP than in asymptomatic controls (p < 0.05). Many of the self-report measures, but none of the physical examination findings were associated with muscle stiffness., Conclusion: Resting lumbar muscle stiffness is greater in individuals with LBP than asymptomatic controls and is associated with self-reported pain and disability, but not physical exam findings., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Evidence suggests that suboccipital musculature plays an important role in headache. Proper therapeutic approaches targeting this muscle are needed., Objective: Our aim was to determine with fresh cadavers and ultrasound imaging if a solid needle is able to properly penetrate the obliquus capitis inferior muscle during the application of dry needling., Design: A cadaveric and human descriptive study., Methods: Needling insertion and ultrasound imaging of the obliquus capitis inferior muscle was conducted on 10 pain-free healthy subjects and 5 fresh cadavers. Needling insertion was performed using a 40 mm needle inserted midway between the spinous process of C2 and transverse process of C1. The needle was advanced from a posterior to anterior direction into the obliquus capitis inferior muscle with an inferior-lateral angle to reach the lamina of C2. For the cadaveric study, the obliquus capitis inferior placement was verified by resecting the superficial upper trapezius, splenius capitis, and semispinalis capitis muscles. For ultrasographic study, a linear transducer was aligned with the long axis of the obliquus capitis inferior muscle after needle insertion., Results: Both the cadaveric and ultrasonic studies showed that the needle penetrated the obliquus capitis inferior muscle during its insertion and that the tip of the needle rested against C2 laminae, thereby reaching the targeted muscle., Conclusion: This anatomical and ultrasound imaging study supports the assertion that needling insertion of the obliquus capitis inferior muscle can be properly conducted by an experienced clinician., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study investigated the effects of multiple freeze-thaw (F-T) cycles on water mobility, microstructure damage and protein structure changes in porcine longissimus muscle. The transverse relaxation time T 2 increased significantly when muscles were subjected to multiple F-T cycles (P<0.05), which means that immobile water shifted to free water and the free water mobility increased. Multiple F-T cycles caused sarcomere shortening, Z line fractures, and I band weakening and also led to microstructural destruction of muscle tissue. The decreased free amino group content and increased dityrosine in myofibrillar protein (MP) revealed that multiple F-T cycles caused protein cross-linking and oxidation. In addition, the results of size exclusion chromatography, circular dichroism spectra, UV absorption spectra, and intrinsic fluorescence spectroscopy indirectly proved that multiple F-T cycles could cause protein aggregation and degradation, α-helix structure disruption, hydrophobic domain exposure, and conformational changes of MP. Overall, repeated F-T cycles changed the protein structure and water distribution within meat., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To examine the histopathological changes in spinal tissues of ankylosing spondylitis (AS) patients., Methods: Tissue samples from 10 AS patients and 10 control subjects were obtained. Hematoxylin and eosin, picrosirius, Masson and van Gieson stainings were utilized to determine the pathological changes in tissues. Ultrastructural alterations were examined by electronic microscopy. Proteoglycan levels were assessed by enzyme-linked immunosorbent assays (ELISA). Matrix metalloproteinase-3 (MMP-3), transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) levels were evaluated by immunohistochemistry., Results: Our results demonstrate that the density of collagen fibrils was reduced in the supraspinous ligaments of AS tissue and fibrils were loosely and irregularly organized as compared to a regular distribution of collagen fibrils in controls. In ligamentum flava from AS patients, activated fibroblasts with enlarged nuclei were detected, while the number of elastic fibers was greatly decreased. Paraspinal muscle tissues of AS patients exhibited increased collagen fibril accumulation and atrophy. Significantly decreased proteoglycan and elevated MMP-3 levels were found in supraspinous ligament samples from AS patients (P < 0.01). Additionally, the levels of TGF-β1 in ligamentum flava and paraspinal muscle tissues of AS patients were increased (P < 0.01). The expression of TNF-α was also upregulated in the ligamentum flavum (P < 0.01), with no significant difference in the paraspinal muscle between control and AS patients (P > 0.05)., Conclusions: Our findings reveal histopathological changes that occur in certain spinal tissues of AS patients and suggest that increased levels of MMP-3 and TGF-β1 may contribute to the pathogenesis of AS., (© 2014 The Authors. International Journal of Rheumatic Diseases published by Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.)