Third head of the biceps brachii muscle originated from the greater tubercle connecting long and short heads: a case report / Tercera cabeza del músculo bíceps braquial originada en la tubrosidad mayor del húmero conectando las cabezas larga y corta: informe de un caso

Variation in the biceps brachii muscle is extremely frequent and has a clinical significance. During an educational dissection, third head of the biceps brachii muscle was found on the left side in a Korean cadaver. The short and long heads showed normal morphology and course: however, additional head originated from the greater tubercle connected to long head of biceps brachii muscle and crossed the musculocutaneous nerve perpendicularly. And then, it was inserted into short head of the biceps brachii muscle. The author describes this previously novel case report and discusses the clinical implications of such a variant.

La variación en el músculo bíceps braquial es extremadamente frecuente y tiene un significado clínico. Durante una disección educativa, se encontró la tercera cabeza del músculo bíceps braquial en el lado izquierdo de un cadáver coreano. Las cabezas cortas y largas mostraron una morfología y curso normales: sin embargo, la cabeza adicional se originó de la tuberosidad mayor conectado a la cabeza larga del músculo bíceps braquial y cruzaba el nervio musculocutáneo perpendicularmente, insertándose en la cabeza corta del músculo bíceps braquial. El autor describe este informe de un caso novedoso y discute las implicaciones clínicas de tal variante.

The third head of the biceps brachii muscle perforated by the musculocutaneous nerve / La tercera cabeza del músculo bíceps braquial perforada por el nervio musculocutáneo

During an educational dissection, the third head of the biceps brachii muscle was found on the left side in a 63-yearold female Korean cadaver. The short and long heads showed normal morphology, and their courses were as follows: The third head was originated from the middle level of the humerus under the short head and inserted in the conjoined tendon of the long and short heads of the biceps brachii muscle. The musculocutaneous nerve penetrated the third head of the biceps brachii muscle and became the lateral cutaneous nerve of the forearm. The authors describe this novel case and discuss the clinical implications of such a variation.

Durante una disección educativa, la tercera cabeza del músculo bíceps braquial se encontró en el lado izquierdo en un cadáver coreano de 63 años de edad. La cabeza corta y la cabeza larga mostraron una morfología normal, y se presentaron de la siguiente forma: La tercera cabeza se originó en el nivel medio del húmero, inferior a la cabeza corta, y se insertó en el tendón unido de las cabezas larga y corta del músculo bíceps braquial. El nervio musculocutáneo penetró en la tercera cabeza del músculo bíceps braquial para transformarse en el nervio cutáneo lateral del antebrazo. Los autores describen este nuevo caso y discuten las implicaciones clínicas de esta variación.

Incidence of Third Head of Biceps Brachii in South Indian Population

Additional heads of the biceps brachii muscle of arm have the clinical importance, because they mislead the surgeon in arm surgical procedures. Existence of such variation is one of the reasons for neurovascular compression in the arm region. The present study was conducted to find out the incidence of third head of biceps brachii among 80 samples in South Indian population. The third head of biceps brachii was found in right side in one case which was 13.7 cm in length and arising from antero medial wall of lower part of shaft of humerus. Incidence of the study is 1.25% in South Indians. Occurrence of supernumerary third head of biceps is rare in Indian population.

The Third Head of Biceps Brachii Muscle in Korean: Anatomical Study / 체질인류학회지

The goal of this study was to investigate the incidence of third head of biceps brachii (THBB) for understanding unexpected cases in clinical practice. The sample consisted of 214 upper extremities from 107 adult cadavers donated to science (70 males and 37 females; age, 51-87 years). Cases with pathological changes or trauma to the upper limbs were excluded. THBB was found in 14 of the 214 upper extremities. The incidence of variation was approximately 6.5%. THBB was found in 10 male limbs and 4 female limbs, and none of the cases was bilateral. THBB was a flat muscular belly-like structure that originated from the anteromedial surface of the humerus between the insertion of the coracobrachialis and the origin of the brachialis. This finding may be clinically important because the musculocutaneous nerve is subjected to compression by the bulky third head.

Unusual third head of the sternocleidomastoid muscle from the investing layer of cervical fascia / Inusual tercera cabeza del músculo esternocleidomastoideo desde la lámina superficial de la fascia cervical

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 disposición en capas de fibras son las variaciones reportadas del músculo esternocleidomastoideo. En el presente estudio, se presenta un origen poco habitual de la tercera cabeza del músculo esternocleidomastoideo en un cadáver de sexo masculino de 60 años. La cabeza supernumeraria se originaba en la lámina superficial de la fascia cervical en el techo del triángulo subclavio próximo de la clavícula y cruzaba oblicuamente hacia arriba y adelante para fusionarse con la cabeza clavicular. La inserción e inervación del músculo eran normales...

Incidence of the third head of biceps brachii in western Indian population.

Backgrond: Biceps brachii is muscle of the flexure compartment of the arm. Anatomic variation of the biceps brachii muscle is one of the most variations in upper limb. The most common variation is a third head, but four, five or even seven heads have been reported. This variation may present as a group of accessory fascicles arising from the coracoids process, Pectoralis major tendon, proximal head of the humerus, articular capsule of the humerus or from humerus itself. Aim: to report the occurrence of the third head of biceps brachii in a sample Indian population along the western region of India, and to compare with other racial groups from previous study. Method: A prospective evaluation was conducted on cadavers at Govt. Medical College, Surat in Gujarat. The upper limbs of 32 cadavers were dissected and observed for variation in the origin and insertion of the biceps brachii muscle bilaterally. Result: A third head for the biceps brachii muscle were found in six arms. The variations were bilaterally. The short & long head were normal however third head was humeral origin and also arose from pectoralis major tendon and inserted into the conjoined tendon of the biceps brachii muscle as usual. The variant was present in three males (9.37%, n=32). Conclusion: Awareness of incidence of this variation is necessary to avoid complication during pre-operative procedure or surgeries in the upper limb.