Kumar Hitendra, Das Srijit, Rath Gayatri
Department ofAnatomy, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi-110029, India.
Bratisl Lek Listy. 2008;109(2):76-8.
The biceps brachii muscle is known to show variations in the number of heads. This study was performed to evaluate the variations in the origin of the biceps brachii muscle heads.
Both extremities of 48 formalin fixed cadavers (n = 96) were studied for abnormal heads of biceps brachii muscle. The flexor compartment of the arm was dissected and the attachments of the biceps brachii muscle were studied in detail. Appropriate photographs were taken.
Among ninety six upper limbs studied, we observed three heads of biceps on both sides of a male cadaver aged 56 yrs (3.33%). The two heads of the biceps arose from its usual position but the anomalous third head arose from the anterior limb of the 'V' shaped insertion of the deltoid muscle on the humerus. The third head was found to fuse with the common belly of the muscle well before the bicipital tendon and its aponeurosis. Bilaterally this third head was supplied by a twig of the musculocutaneous nerve. No other abnormalities relating to the biceps were observed in any of the sides of the other 47 cadavers (n = 94).
Our study revealed that the incidence of third head of biceps brachii may be approximately 3.33 % but larger studies are needed to confirm this fact. The third head of biceps brachii may be an incidental finding at autopsy or during routine anatomical dissections. Unless symptomatic, the third head of biceps brachii may not be detected in clinical studies (Fig. 3, Ref. 15).
已知肱二头肌的头数会出现变异。本研究旨在评估肱二头肌各头起点的变异情况。
对48具经福尔马林固定的尸体（n = 96）的双侧上肢进行研究，以观察肱二头肌的异常头。解剖臂部的屈肌间隙，并详细研究肱二头肌的附着情况。拍摄了适当的照片。
在研究的96条上肢中，我们在一名56岁男性尸体的双侧观察到三头肱二头肌（3.33%）。肱二头肌的两个头起自其正常位置，但异常的第三个头起自三角肌在肱骨上“V”形附着的前支。发现第三个头在肱二头肌腱及其腱膜之前就与肌的共同肌腹融合。双侧的第三个头由肌皮神经的一个分支供应。在其他47具尸体（n = 94）的任何一侧均未观察到与肱二头肌相关的其他异常。
我们的研究表明，肱二头肌第三头的发生率可能约为3.33%，但需要更大规模的研究来证实这一事实。肱二头肌第三头可能在尸检或常规解剖时偶然发现。除非有症状，肱二头肌第三头在临床研究中可能无法被检测到（图3，参考文献15）。
