The biceps brachii muscle and its distal insertion: observations of surgical and evolutionary relevance

Abstract

The investigation revealed anatomical variations including supernumerary heads (20%) and 'fusion' of the muscle proximal to tendon formation and a spiralling arrangement of the tendon in its approach to the radial tuberosity. The data from the present study was reviewed in the context of previous studies on the anatomy of this muscle and speculation on the evolutionary basis of the variations and their clinical implications are discussed.

Morphology and clinical implication of the extra-head of biceps brachii muscle

“…Occurrence of biceps third head is a common variant [10 , 17], but the presence of 4, 5 or more heads have been reported [24]. However, rare variations had been reported regarding the biceps insertion, absence of its long or short heads [5,13].…”

“…From 1 to 7 extra-heads of biceps were reported [12,24]. These variations had been found in about 9-22% of cadavers [5]. In addition, insertional variations of the biceps muscle were reported as well [15].…”

A rare musculo-septal aponeurotic tunnel in the arm with anomalous arterial pattern

“…BBM has been found to have additional heads in as high as 20% of the population. 2 The present case reports the presence of a musculo-septal aponeurotic tunnel due to a variant insertion of BT with associated entrapment of MN and BA which has not been reported in the past and is rare. Awareness of such a variation helps the surgeon in treating the vascular and nerve entrapment symptoms by simple release of these surrounding compressing structures.…”

“…1 Supernumerary heads are the most commonly reported variations in this muscle. 2 The insertion of all the accessory heads was reported to be to the radial tuberosity. There is paucity of literature regarding the variations in the insertion of this muscle.…”

Prevalencia de Cabeza Accesoria (Humeral) del Músculo Bíceps Braquial: Revisión de la Literatura

“…La forma de terminación del músculo también es pasible de presentar variaciones, entre ellas un fascículo supernumerario para la ulna o para el radio (Testut & Latarjet;Dirim et al;Koulouris et al, 2009;Cucca et al, 2010;Shute et al, 2013). La cabeza accesoria del músculo bíceps braquial también puede tener una terminación variable, si bien lo más común es su unión al tendón común, en oportunidades puede unirse a la cabeza larga o a la cabeza corta o bien mantenerse independiente y terminar en la aponeurosis bicipital (Reilly & Kamineni).…”