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The biceps brachii is located in the anterior compartment of the arm, which can show numerous morphological variations. During anatomical dissection, an interesting additional muscle was found: the third head of the biceps brachii originated from the short head of the same muscle. The 97.77 mm long muscle belly was directed medially over the arm and then passed into the common tendon (15.97 mm), which thereafter split into aponeurosis and tendon. The 26.33 mm aponeurosis passed and joined the fascia of the forearm. The tendon of the third head of the biceps brachii then gave rise to the ulnar head of the pronator teres muscle. Such an accessory structure could cause neurovascular compression involving the brachial artery and median nerve. Knowledge of the morphological variability of this region is essential not only for anatomists but also for clinicians. [ABSTRACT FROM AUTHOR]

The anatomy of the biceps brachii muscle has been a subject of interest to many researchers. In particular, the presence of one or more accessory heads has been reported to be the most common variation of the biceps brachii muscle. In fact, contemporary knowledge is quite inconsistent and lacks a definitive summary. Taking this into account, the present study aims to investigate the overall prevalence of the accessory heads and related questions, such as their broad morphological features, population variance, sexual dimorphism, side distribution or the changes in prevalence rates over time. A literature search of major scientific databases was conducted and produced 78 eligible articles, including 10,603 upper limbs, for our study. Relevant data were extracted and consequently analysed with the use of random‐effects meta‐analysis. As a result, the accessory heads occur with an overall prevalence of 9.6% (95% CI 8–11%) and by far the most common is the presence of a single accessory head (8.4%; 95% CI 7–10%). Additional sub‐analyses revealed that accessory heads appear more frequently unilaterally and in males. Differences between the occurrence on the right or left side were not significant. Moreover, a decreasing trend in prevalence rates over time was observed, pointing towards an evolutionary adaptation. The innervation and blood supply of the accessory heads are nearly identical to that of the normal biceps brachii muscle. Although the accessory heads are usually asymptomatic, their potential presence must be kept in mind while interpreting various conditions. In addition, their direct clinical importance is speculated and is thought that they might be conductive to several pathological processes around the shoulder girdle and brachial region. While many of the morphological and morphometric aspects of the accessory heads are well documented, their functional value is still a matter for future investigations. [ABSTRACT FROM AUTHOR]

Context: Biceps brachii muscle (BBm) is a very variable muscle, the variations being associated with a variety of clinical conditions. This study delves on anatomical variations in this muscle, possible phylogenic causes for their frequency and their clinical importance. Aims: The aim was to study anatomy of bicep brachii muscle, its variations and their clinical importance. Subjects and Methods: A total of 60 upper limbs preserved in 10% formalin were dissected meticulously to study anatomical details of the BBm. Results: The incidence of variation in anatomy of BBm was 15%, with incidence being 11.6% and 3.3% among male and female cadavers studied, respectively. Variation was unilateral in 10% and bilateral in 3.3%. The incidence of third head was 13.3% out of which 3.3% took origin from the capsule of the shoulder joint, 8.3% from humerus, and 1.6% from brachialis muscle. Incidence of extra bellies of insertion was found to be 1.6%. A 3.3% incidence was observed in the nerve supply. Conclusions: Variations in BBm are a reflection of its late development in human phylum. The extra bellies can cause neurovascular compression, change the kinematics at the elbow joint and be misinterpreted as tears of muscle on magnetic resonance imaging. They should be watched for in the shoulder as well as elbow joint surgeries. The authors suggest that the extra bellies of BBm instead of being labeled as third, fourth or fifth heads, can be classified as those of origin and insertion and bellies of origin be referred to clearly as capsular, humeral or brachial heads.

The biceps brachii is one of three muscles of the anterior compartment of arm. Variations of the biceps brachii are not rare. The most frequent is the existence of a third head called the humeral head by Le Double (1897) (Rodríguez-Vázquez et al., 1999). Our article is based on the unexpected result of a routine dissection class held for medical students. Dissection was performed according to the guidelines accepted by the anatomy department (Seichert, 1999). We describe a third (accessory) head of the biceps brachii. In addition of two regular heads, the third head originated together with the short head from the coracoid process and had three insertions on the humerus after enfolding the median nerve and the brachial artery. This particular variation is important from a clinical perspective as the third head may cause entrapment syndrome of the median nerve and hypoperfusion of the upper limb due to compression of the brachial artery.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction Biceps brachii muscle belongs to the flexor group of muscles in arm. As Biceps brachii is double headed muscle. It is one of the known variable muscles of human body in terms of number and morphology. Material and Method During routine human cadaveric dissection for the purpose of teaching medical undergraduates in our department. The upper limb of embalmed adult male cadaver was dissected as per the standard method to note the origin, insertion, and nerve supply of biceps brachii. Results The three headed biceps brachii was found unilaterally on right side in adult male cadaver. The long and short head had normal origin, but third head originated from humerus below insertion of coracobrachialis and inserted with main muscle belly and innervated by musculocutaneus nerve. Conclusion Variant biceps brachii may confuse a surgeon who performs procedures on the arm and may lead to iatrogenic injuries. The surgeons and traumatologists have to keep suchmuscular variations in mind. So the knowledge of existence of its variation is important for anaesthetists and surgeons. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Summary: A study of the incidence of the third head of the biceps brachii (caput accessorium) was carried out in the Department of Anatomy, Kasturba Medical College, Mangalore, India. The observations were made during routine cadaveric dissections to teach the undergraduate students. Forty-eight cadavers were included in the study. The occurrence of this anomaly and its morphology are discussed. [Copyright &y& Elsevier]