Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland.
Laboratory of Anatomy, Faculty of Medicine, Rouen University, France.
Ann Anat. 2022 Jan;239:151825. doi: 10.1016/j.aanat.2021.151825. Epub 2021 Sep 3.
The coracobrachialis muscle, along with the brachialis and biceps brachii muscles, belong to the anterior group of the brachial region. It is characterized by high level of morphological variabilities, with a common variation being the coracobrachialis longus (CBL) muscle. The CBL may be recognized as a distal part of the coracobrachialis muscle, originating from the anteromedial surface of the humerus, however, the two muscles are distinct from each other, and the distal attachment of the CBL is longer and located closer to the elbow joint. The CBL muscle may also be inserted on to various structures. The aim of the present study was to determine the frequency of the CBL muscle among a studied population, and to prepare a classification based on its morphological features.
Classical anatomical dissection was performed on 100 upper limbs from fifty human cadavers (30 female and 20 male) fixed in 10% formalin solution.
The coracobrachialis muscle was found in all individuals, and the CBL muscle was present in 11%, i.e. 11 upper limbs: four women, and seven men; five left and six right. Significantly, in all cadavers in which the coracobrachialis longus was found, its presence was unilateral (five left and six right). A new classification of the CBL can be proposed based on its insertion: Type I characterized by a distal attachment located on the medial epicondyle (73% of all cases of the CBL) and Type II by an insertion into the olecranon (27% of all cases of the CBL).
The CBL muscle is morphologically variable. More studies focused on the course of this muscle among various populations are needed. Nevertheless, our findings indicate that the CBL muscle could be classified as a distinct muscle.
喙肱肌与肱二头肌和肱肌一起属于臂前区的肌群。它具有高度的形态变异性，常见的变异是喙肱肌长头（CBL）。CBL 可被认为是喙肱肌的远端部分，起于肱骨的前内侧面，然而，这两块肌肉彼此不同，CBL 的远端附着更长，更靠近肘关节。CBL 肌肉也可能插入到各种结构中。本研究旨在确定研究人群中 CBL 肌肉的频率，并根据其形态特征进行分类。
对 100 具福尔马林固定的人体尸体（30 名女性和 20 名男性）的 100 个上肢进行了经典的解剖学解剖。
在所有个体中均发现了喙肱肌，而 CBL 肌肉存在于 11%，即 11 个上肢：4 名女性，7 名男性；5 个左侧，6 个右侧。值得注意的是，在所有发现 CBL 长头的尸体中，其存在均为单侧（5 个左侧，6 个右侧）。可以根据其插入方式提出 CBL 的新分类：以附着于内上髁为特征的Ⅰ型（所有 CBL 病例的 73%）和以插入尺骨鹰嘴为特征的Ⅱ型（所有 CBL 病例的 27%）。
CBL 肌肉形态多变。需要更多针对不同人群中该肌肉行程的研究。然而，我们的发现表明，CBL 肌肉可以被分类为一个独特的肌肉。
