Abstract:
Muscle spindles have unique anatomical characteristics that can be directly affected by the surrounding tissues under physiological and pathological conditions. Understanding their spatial distribution and density in different muscles is imperative to unravel the complexity of motor function. In the present study, the distribution and number/density of muscle spindles in human and animal muscles were reviewed. We identified 56 articles focusing on muscle spindle distribution; 13 articles focused on human muscles and 43 focused on animal muscles. The results demonstrate that spindles are located at the nerve entry points and along distributed vessels and they relate to the intramuscular connective tissue. Muscles\' deep layers and middle segments are the main topographic distribution areas. Eleven articles on humans and thirty-three articles on animals (totaling forty-four articles) focusing on muscle spindle quantity and density were identified. Hand and head muscles, such as the pronator teres/medial pterygoid muscle/masseter/flexor digitorum, were most commonly studied in the human studies. For animals, whole-body musculature was studied. The present study summarized the spindle quantity in 77 human and 189 animal muscles. We identified well-studied muscles and any as-yet unfound data. The current data fail to clarify the relationship between quantity/density and muscle characteristics. The intricate distribution of the muscle spindles and their density and quantity throughout the body present some unique patterns or correlations, according to the current data. However, it remains unclear whether muscles with fine motor control have more muscle spindles since the study standards are inconsistent and data on numerous muscles are missing. This study provides a comprehensive and exhaustive approach for clinicians and researchers to determine muscle spindle status.
摘要:
肌肉纺锤体具有独特的解剖特征,在生理和病理条件下可以直接受到周围组织的影响。了解它们在不同肌肉中的空间分布和密度对于揭示运动功能的复杂性至关重要。在本研究中,综述了肌肉纺锤体在人和动物肌肉中的分布和数量/密度。我们确定了56篇专注于肌肉纺锤体分布的文章;13篇专注于人类肌肉,43篇专注于动物肌肉。结果表明,纺锤体位于神经进入点并沿着分布的血管,它们与肌内结缔组织有关。肌肉的深层和中段是主要的地形分布区。确定了11篇关于人类的文章和33篇关于动物的文章(总计44篇),重点是肌肉纺锤体的数量和密度。手和头部肌肉,例如旋前肌/内侧翼状肌/咬肌/指屈肌,在人类研究中最常见的研究。对于动物来说,研究了全身肌肉组织。本研究总结了77人和189只动物肌肉的纺锤体数量。我们确定了经过充分研究的肌肉和任何尚未找到的数据。当前数据未能阐明数量/密度与肌肉特征之间的关系。肌肉纺锤的复杂分布及其密度和数量在整个身体呈现出一些独特的模式或相关性,根据目前的数据。然而,目前尚不清楚精细运动控制的肌肉是否有更多的肌肉纺锤,因为研究标准不一致,许多肌肉的数据缺失。这项研究为临床医生和研究人员确定肌肉纺锤状态提供了一种全面而详尽的方法。