Wysiadecki G, Polguj M, Krasucki K, Zytkowski A, Smigielski J, Topol M, Orkisz S
Department of Normal Anatomy, Medical University of Lodz, Poland.
Folia Morphol (Warsz). 2014 May;73(2):216-23. doi: 10.5603/FM.2014.0032.
The deltoid muscle (DM) plays an essential role in retaining the stability and correct function of the upper limb. The aims of the study were to perform a detailed morphological analysis of the DM including its innervation, structure, attachments and relationship with adjacent structures.
The study was carried out on 17 formalin-fixed cadavericupper limbs. After dissection of the shoulders, the DM was visualised and analysed.The following measurements of the muscle were performed for all cases: width of attachments (acromial, clavicular, spinal), entire width of origin, length of the component parts (acromial, clavicular, and spinal) and length of the arm.
In all specimens, a characteristic 'segmented' innervation scheme of the DM was observed. The axillary nerve (AN) was always divided into an anterior branch (abAN) and a posterior branch (pbAN). Two variations of the DM innervation were distinguished: variation I, where the clavicular and the acromial parts were innervated by the abAN, while the spinal part was supplied both by abAN (anterior fibres) and by pbAN (posterior fibres), and variation II, in which the spinal part did not have double innervation - the abAN innervation area covered only the acromial and clavicular parts, and the entire spinal part was supplied by pbAN. Both variations had a segmented arrangement of sub-branches reaching individual parts of the DM, which was particularly distinct in the clavicular and acromial parts. Correlations were found between the entire width of the DM originand the length of the arm (p = 0.001), between the length of the acromial part of the DM and the length of the arm (p = 0.003), between the width of the spinal attachment and the length of the spinal part (p = 0.002), and between the width of the spinal attachment and the length of the arm (p = 0.0008).
The study confirmed the existence of a characteristic segmented innervation scheme of the DM which corresponds with the segmented morphology of its individual parts. An analysis of the internal structure of the muscle specific architectonics based on the tendon system was also presented.
三角肌在维持上肢的稳定性和正常功能方面起着至关重要的作用。本研究的目的是对三角肌进行详细的形态学分析，包括其神经支配、结构、附着点以及与相邻结构的关系。
本研究对17具经福尔马林固定的尸体上肢进行。在解剖肩部后，对三角肌进行观察和分析。对所有病例进行了以下肌肉测量：附着点宽度（肩峰、锁骨、脊柱）、起始部总宽度、各组成部分长度（肩峰、锁骨、脊柱）以及臂长。
在所有标本中，均观察到三角肌具有特征性的“分段”神经支配模式。腋神经总是分为前支（腋神经前支）和后支（腋神经后支）。区分出了三角肌神经支配的两种变异：变异I，其中锁骨部和肩峰部由腋神经前支支配，而脊柱部由腋神经前支（前纤维）和腋神经后支（后纤维）共同支配；变异II，其中脊柱部没有双重神经支配——腋神经前支的支配区域仅覆盖肩峰部和锁骨部，整个脊柱部由腋神经后支支配。两种变异的分支都呈分段排列，延伸至三角肌的各个部分，在锁骨部和肩峰部尤为明显。发现三角肌起始部总宽度与臂长之间存在相关性（p = 0.001），三角肌肩峰部长度与臂长之间存在相关性（p = 0.003），脊柱附着点宽度与脊柱部长度之间存在相关性（p = 0.002），以及脊柱附着点宽度与臂长之间存在相关性（p = 0.0008）。
本研究证实了三角肌存在特征性的分段神经支配模式，这与其各部分的分段形态相对应。还基于肌腱系统对肌肉特定结构的内部结构进行了分析。
