Unusual Third Head of the Sternocleidomastoid Muscle from the Investing Layer of Cervical Fascia Inusual Tercera Cabeza del M迆sculo Esternocleidomastoideo desde la L芍mina Superficial de la Fascia Cervical

作者：Srinivasa Rao Sirasanagandla; Kumar M R Bhat; Narendra Pamidi; S Nagabhooshana Somayaji

来源：International Journal of Morphology, 2012.

• Musculo esternocleidomastoideo
• Variacion anatomica
• Tercera cabeza
• Sternocleidomastoid muscle
• Anatomical variation
• Third head

The abnormal origin, presence of additional head and layered arrangement of fibers are the reported variations of sternocleidomastoid muscle in the past. In the present case we report a rare unusual origin of third head of the sternocleidomastoid muscle in a 60 year-old male cadaver. This additional head originated from the investing layer of cervical fascia in the roof of the subclavian triangle close to the clavicle and traversed obliquely upward, forward and fused with clavicular head. The insertion and nerve supply of the muscle was found to be normal. El origen anormal, presencia de una cabeza adicional y disposici車n en capas de fibras son las variaciones reportadas del m迆sculo esternocleidomastoideo. En el presente estudio, se presenta un origen poco habitual de la tercera cabeza del m迆sculo esternocleidomastoideo en un cad芍ver de sexo masculino de 60 a os. La cabeza supernumeraria se originaba en la l芍mina superficial de la fascia cervical en el techo del tri芍ngulo subclavio pr車ximo de la clav赤cula y cruzaba oblicuamente hacia arriba y adelante para fusionarse con la cabeza clavicular. La inserci車n e inervaci車n del m迆sculo eran normales.