Bishop James H, Fox James R, Maple Rhonda, Loretan Caitlin, Badger Gary J, Henry Sharon M, Vizzard Margaret A, Langevin Helene M
Department of Neurological Sciences, University of Vermont, Burlington, Vermont, United States of America.
Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, United States of America.
PLoS One. 2016 Jan 28;11(1):e0147393. doi: 10.1371/journal.pone.0147393. eCollection 2016.
The persistence of back pain following acute back "sprains" is a serious public health problem with poorly understood pathophysiology. The recent finding that human subjects with chronic low back pain (LBP) have increased thickness and decreased mobility of the thoracolumbar fascia measured with ultrasound suggest that the fasciae of the back may be involved in LBP pathophysiology. This study used a porcine model to test the hypothesis that similar ultrasound findings can be produced experimentally in a porcine model by combining a local injury of fascia with movement restriction using a "hobble" device linking one foot to a chest harness for 8 weeks. Ultrasound measurements of thoracolumbar fascia thickness and shear plane mobility (shear strain) during passive hip flexion were made at the 8 week time point on the non-intervention side (injury and/or hobble). Injury alone caused both an increase in fascia thickness (p = .007) and a decrease in fascia shear strain on the non-injured side (p = .027). Movement restriction alone did not change fascia thickness but did decrease shear strain on the non-hobble side (p = .024). The combination of injury plus movement restriction had additive effects on reducing fascia mobility with a 52% reduction in shear strain compared with controls and a 28% reduction compared to movement restriction alone. These results suggest that a back injury involving fascia, even when healed, can affect the relative mobility of fascia layers away from the injured area, especially when movement is also restricted.
急性背部“扭伤”后持续存在的背痛是一个严重的公共卫生问题，其病理生理学尚不清楚。最近的研究发现，慢性下背痛（LBP）患者经超声测量显示胸腰筋膜厚度增加且活动度降低，这表明背部筋膜可能参与了LBP的病理生理过程。本研究使用猪模型来检验以下假设：通过使用“捆绑”装置将一只脚与胸部束带相连8周以限制运动，并结合局部筋膜损伤，可在猪模型中通过实验产生类似的超声检查结果。在第8周时间点，对未干预侧（损伤和/或捆绑侧）进行被动髋关节屈曲时胸腰筋膜厚度和剪切平面活动度（剪切应变）的超声测量。仅损伤就导致未损伤侧筋膜厚度增加（p = 0.007）以及筋膜剪切应变降低（p = 0.027）。仅限制运动并未改变筋膜厚度，但确实降低了未捆绑侧的剪切应变（p = 0.024）。损伤加运动限制的组合对降低筋膜活动度具有累加效应，与对照组相比，剪切应变降低了52%，与仅运动限制相比降低了28%。这些结果表明，涉及筋膜的背部损伤即使愈合，也会影响远离损伤区域的筋膜层的相对活动度，尤其是在运动也受到限制时。
