Kervancioglu P, Orhan M
Anatomy Department, Gaziantep University Medical Faculty, Turkey.
Folia Morphol (Warsz). 2011 May;70(2):116-20.
The biceps brachii (BB) is as one of the most variable muscles in the human body in terms of number and morphology of its heads. The most frequent variation is the presence of a third head, which has been reported by several authors in different populations. Our aim was to find the occurrence of the supernumerary head of BB in Turkish foetuses. Out of the 24 upper limbs of the foetuses, two (8.33%) arms were found to have a three-headed BB. The variations were present unilaterally in the right arm of one male foetus and one female foetus. In one of the cases, the third head of BB originated from the anteromedial aspect of the humerus just distal to the insertion of the coracobrachilais, medial to the brachialis, and in the other the third head was a thin muscle bundle, which arose on the lateral side of the insertion of coracobrachialis and over the origin of the brachialis. Both of them were extended distally and joined the common tendon. The occasional presence of the three-headed BB in the foetuses observed in the present study was similar to those of adults reported in previous studies. In conclusion, these variations are not rare and are interesting not only to anatomists but also to orthopaedic surgeons, plastic surgeons, traumatologists, physiotherapists, doctors dealing with sports medicine, and radiologists.
肱二头肌（BB）在人体中是头部数量和形态变化最多的肌肉之一。最常见的变异是出现第三个头，已有多位作者在不同人群中报道过。我们的目的是找出土耳其胎儿中肱二头肌多余头的出现情况。在24例胎儿的上肢中，发现有两例（8.33%）手臂的肱二头肌有三个头。变异仅出现在一名男性胎儿和一名女性胎儿的右臂。其中一例中，肱二头肌的第三个头起源于肱骨的前内侧，恰好在喙肱肌止点的远侧，肱肌的内侧；另一例中，第三个头是一束细肌束，起于喙肱肌止点的外侧及肱肌起点的上方。二者均向远侧延伸并汇入共同肌腱。本研究中观察到的胎儿偶尔出现三头肱二头肌的情况与先前研究报道的成年人情况相似。总之，这些变异并不罕见，不仅对解剖学家，而且对骨科医生、整形外科医生、创伤科医生、物理治疗师、运动医学医生和放射科医生来说都很有意义。
