Agten Anouk, Stevens Sjoerd, Verbrugghe Jonas, Eijnde Bert O, Timmermans Annick, Vandenabeele Frank
Department of Rehabilitation Sciences and Physiotherapy, Hasselt University, Rehabilitation Research Centre, Faculty of Rehabilitation Sciences, Diepenbeek, Belgium.
Department of Cardio and Internal Systems, Hasselt University, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Diepenbeek, Belgium.
Anat Cell Biol. 2020 Jun 30;53(2):143-150. doi: 10.5115/acb.20.009.
The metabolic capacity of a muscle is one of the determinants of muscle function. Muscle fiber type characteristics give an indication about this metabolic capacity. Therefore it might be expected that the lumbar multifidus (MF) as a local stabilizer contains higher proportions of slow type I fibers, compared to the erector spinae (ES) as a global mobilizer. The aim of this study is to determine the muscle fiber characteristics of the ES and MF to provide insight into their structural and metabolic characteristics, and thereby the functional capacity of both muscles. Muscle fiber type characteristics in the ES and MF were investigated with an immunofluorescence staining of the myosin heavy chain isoforms. In both the ES and MF, type I muscle fibers are predominantly present. The cross-sectional area (CSA) of type I muscle fibers is significantly larger in the lumbar MF compared to the ES. However, the mean muscle fiber type percentage for type I was not significantly different, which resulted in an insignificant difference in relative cross-sectional area (RCSA) for type I. No significant differences were found for all other muscle fiber types. This may indicate that the MF displays muscle fiber type characteristics that tend to be more appropriate to maintain stability of the spine. However, because we could not demonstrate significant differences in RCSA between ES and MF, we cannot firmly state that there are functional differences between the ES an MF based only on structural characteristics.
肌肉的代谢能力是肌肉功能的决定因素之一。肌纤维类型特征可反映这种代谢能力。因此，可以预期，作为局部稳定肌的腰多裂肌（MF）与作为整体运动肌的竖脊肌（ES）相比，含有更高比例的慢肌I型纤维。本研究的目的是确定竖脊肌和腰多裂肌的肌纤维特征，以深入了解它们的结构和代谢特征，从而了解这两块肌肉的功能能力。通过对肌球蛋白重链异构体进行免疫荧光染色，研究了竖脊肌和腰多裂肌的肌纤维类型特征。在竖脊肌和腰多裂肌中，主要存在I型肌纤维。与竖脊肌相比，腰多裂肌中I型肌纤维的横截面积（CSA）明显更大。然而，I型肌纤维的平均百分比没有显著差异，这导致I型肌纤维的相对横截面积（RCSA）差异不显著。其他所有肌纤维类型均未发现显著差异。这可能表明，腰多裂肌表现出的肌纤维类型特征更适合维持脊柱的稳定性。然而，由于我们未能证明竖脊肌和腰多裂肌在RCSA上存在显著差异，因此我们不能仅凭结构特征就笃定竖脊肌和腰多裂肌之间存在功能差异。
