Biceps Brachii

This muscle is very variable. In about 12% of arms, a humeral head is found in addition to those usually found arising from the coracoid process (medial or short head) and the glenoid lip of the scapula (lateral or long head). A biceps with more than two heads is found in about 8% of Chinese, 10% of white Europeans, 12% of Black Africans, and about 18% of Japanese.

A biceps may be composed of 1 to 5 heads. In one small study of 18 subjects, an accessory head was found six times, and a fourth head was found once. The variations appeared three times on the right side, two times on the left and one time on the both sides.The most common accessory slip is one arising from the humerus at the insertion of coracobrachialis, extending between it and the brachialis muscle. It joins the short head, but most of its fibers join the semilunar fascia. It may be isolated and terminate entirely in the fascia. Mori described various origins of the third or accessory head as follows: In 50 arms there were 10 (20%) arms with a third head of the biceps. The origins of these additional heads were:

  1. The distal portion of the deltoid tuberosity, 4 arms, 8%.
  2. Near the point of the humeral insertion of coracobrachialis, 3 arms, 6% and
  3. The terminal tendon of pectoralis major, 2 arms, 4%.

The two other accessory heads are rare and take several different forms. When fully developed, they arise close together from the neck of the humerus, below the lesser tubercle and behind the pectoral tendon to which they may be more or less joined. The more lateral of the two slips joins the long head of the muscle, whereas the medial joins the short head.

In other instances, the two heads of the biceps muscle may be totally separate or fused and either head may be absent. In the absence of the long head, the tendon may be found arising from the bicipital groove, one of the tubercles, the capsule of the joint, or the tendon of pectoralis major. The tendon may be doubled or it may be represented only by the lacertus.

The lacertus, which may be doubled, may compress the median nerve as found in the anterior interosseous nerve syndrome. An accessory slip may arise from the deltoid muscle. At the distal end of the biceps muscle, various muscular or tendinous slips have been described connecting biceps to the lower end of the humerus, the ulna, radius, antebrachial fascia, or neighboring muscles. Thereby, supernumerary heads may also arise from brachialis, brachioradialis, or the fascia or fibers of the pronator teres muscle. da Silva Leal summarized the entire literature to 1926 and reported that supernumerary heads of the biceps occur in about 10% of individuals (148 reports in 1453 individuals).

Also a fleshy slip may also arise from the medial border of biceps and pass to the medial intermuscular septum or medial epicondyle over the brachial artery. The brachial artery may actually pass through this slip or its tendon. This is a potential entrapment site for the brachial artery. Other fascicles have been reported passing to brachialis, pronator teres, flexor carpi radialis, flexor digitorum profundus, or to the lateral side of brachioradialis.

The long head of biceps may be perforated by a duplicated musculocutaneous nerve.

Macalister (1875) reported the variations of biceps brachii as follows;

  1. The muscle may be entirely suppressed;
  2. The short head may be absent (Meckel);
  3. The long head was found deficient by Otto, Lauth, Henle, Hyrtl, and Macalister;
  4. The fascial insertion was found to be absent in one arm (Macalister);
  5. The radial insertion has been found absent by Petit (1733) and Haller (1768);
  6. The same, with an insertion into the elbow capsule and the coronoid process, was found in a case of congenital absent of the radius by Gruber;
  7. The two heads of the muscle may be separate for the entire length of the muscle (Maclaister); a similar case is reported by Riverius (1545); in another case the muscle was split for three-fourths of its course;
  8. The long head was found doubled by Moser;
  9. I have found the long head arising from the capsular ligament;
  10. Or from the bicipital groove;
  11. A doubled coronoid head was described by Wood and by Macalister;
  12. This anomalous portion may join the main body of the muscle, or else it may unite with the normal coracoid head before that portion of the biceps joins the long head;
  13. An extension of the coracoid head from the coracoacromial ligament was found six times by Macalister, other cases by Wood;
  14. Macalister reported a slip to the short head from the insertion-tendon of pectorlis minor;
  15. The most common of all varieties of this muscle is the occurrence of a third head, and the most frequently present third head is that from the interval between the coracobrachialis and brachialis anticus (brachialis): the frequency of this variation depends upon the author: Theile, once in nine; Hallett, once in fifteen; Wood, eighteen out of one hundred and seventy-five subjects, and Macalister found it once in ten subjects;
  16. Macalister found a third head arising directly from the brachialis anticus (brachialis). This third head Macalister found crosses the brachial artery (and may compromise it) has also been seen by Quain and Struthers and others; In Struthers' case the muscle covered the artery by a tendinous arch;
  17. A separate slip from coracobracialis continuous with the short head is described by Mr. Wood and Macalister;
  18. A humeral head starting from the insertion of coracobrachialis is reported by Macalister, but it is not as frequent as that arising fron brachialis;
  19. A third head may arise between the insertion of the deltoid and the origin of supinator longus (brachioradialis);
  20. This has been found as a separate muscle, distinct for its whole length, as far as its insertion from the biceps, and is described with the brachioradialis (Gruber, 1848), Theile, Hyrtl. Wagner; Wood and Pietsch describe it as imperfectly separate;
  21. A head like 19 above, but continuous with deltoid has been found by Macalister;
  22. In another similar case Macalister found the usual long head absent;
  23. The same variation may join supinator longus (brachioradialis) instead of deltiod;
  24. A variety of internal third head (15 above), is described by Hyrtl, is that in which the accessory part arises from the internal intermuscular septum;
  25. An instance of the origin of the long tendon of the biceps from the tendon of pectoralis major is described by Koster;
  26. A third head from from the outer lateral tuberosity is described by Meckel;
  27. The long head may attach to the greater tuberosity of hunerus;
  28. 28. Haller describes a third head arising from the outer margin of the bicipital groove by a tendon;
  29. 29. Macalister found an accessory third head arising from the upper border of pronator teres and inserted with the biceps;
  30. A series of four heads was found by Macalister with a usual third humeral origin coexisting with a head from the great tuberosity similar to 26 above;
  31. Wood found a four headed muscle, in which the lateral and menial humeral origins coexisted (15 and 19 above);
  32. Another quadricipital arrangement has been seen by Macalister, where the short head was doubled, and the medial humeral head (15) coexisted with the greater tuberosity head (26) but without the long tendon;
  33. Henle found a quinqueceps (five headed), the normal heads and the third humeral head coexisting with one from the deltoid, and a fifth from the middle of the bicipital groove as high as the tendon of pectoralis major;
  34. In another four-headed biceps which Macalister found ,the two normal heads, and the medial humeral coexisted with an origin from the outer (lateral) lip of the bicipital groove;
  35. Meckel (1826) described a biceps consisting of a short and a humeral head;
  36. Of unusual insertions, Macalister notes a slip from the lateral head inserted separately into the radius is one of the rarest of these (reported by Sels, 1815) and by Rudolphi;
  37. A normal-arising biceps was seen by Mr. Wood to have three insertions- an outer normal portion, giving off a radial tendon and a superficial semilunar fascia; a middle smallest portion was inserted into the fascia, over supinator brevis (supinator) and the bursa of the radial tuberosity; the inner division, which ended in a strong trifurcating tendon, sent a slip to the coronoid origin of the pronator teres, one into the coronoid insertion of brachialis, and one into the coronoid attachment of flexor sublimis;
  38. Kelly found a small tendon detached from the lower end of the biceps, giving origin to part of the flexor carpi radialis;
  39. A slip from biceps to the internal intermuscular septum is described by Quain;
  40. Kelly reported that there arose from the long head of an otherwise normal biceps a tendinous slip, which becoming fleshy, was inserted at the lowest part of the antecubital fossa, by three tendons, one into the fascia over the supinator longus (brachioradialis), a second into the semilunar fascia, and the third dipped into the bottom of the fossa between pronator teres and the supinator muscle;
  41. In a somewhat similar case the muscle (40 above) was inserted by two slips-one into the bursa over the tubercle of the radius under the normal tendon, and the other, into the coronoid process;
  42. Another, and larger accessory biceps muscle is described by Pietsch, which arose by three heads-one from the lateral side of the humerus, one from the medial side of the humerus, and one from the short head of the biceps itself; these three were inserted by a separate tendon into the radius at its tubercle behind the ordinary biceps tendon;
  43. Macalister reported a slip from the biceps to brachialis anticus, running downwarsds and a little inwards;
  44. Theile described a tricipital muscle in which there were two coracoid heads, and a slip from the capsular ligament with no long head;
  45. Macalister found one biceps, which inserted by four slips, besides the normal insertion, to the internal (medial) brachial ligament, to the capsule of the elbow joint, to the coronoid process, and to the pronator teres;
  46. The slip which, arising from the biceps and crossing the brachial artery, is sometimes traceable down as far as the fascia over the pronator teres, is described by Struthers as a "brachio-fascialis;" it is also illustrated by Quain;
  47. A simple fascicle of the biceps inserting into the origin of the pronator teres Macalister has seen three times. It is also described by Clason of Upsala;
  48. Gruber found in a case of deficient radius a biceps possessing a weak coracoid head, two humeral origins, and two insertions-one radial and one ulnar. The absence of biceps brachii has also been reported.

Syn.: m. flexor radii, flexor antibrachii radialis, Zweikopfiger Armmuskel, Speichenbeuger, Biceps Huméral (Cruveilhier).

References

Asvat, E., Candler, P. and E. Sarmiento. (1993) High incidence of the third head of biceps brachii in South African populations. J. Anat. 182:101-104.

Augagneux, -. (1874) Biceps à trois chefs. Lyon Méd. 15:500.

Barrett, J.H. (1935-36) An additional (third and separate) head of the pronator teres muscle. J. Anat. 70:577-578.

de Burlet, H.M. und J. Correljé (1919) Über Variationen des menschlichen Musculus biceps brachii. Gegenbaurs Morphol. Jahrbuch. 50:403-416.

Calori, L. (1866a) Delle corrispondenze del nervo muscolo-cutaneo con il capo soprannumerario del bicipite bracchiale e col bracchiale interno. Mem. Roy. Accad. Sci. Istituto di Bologna 6:149-155.

Calori, L. (1866b) Di alcuni nuovi muscoli soprannumerarii degli arti. Mem. R. Accad. Sci. Istituto di Bologna. S.2., 6:137-147.

Calori, L. (1867) Varieta dei muscoli del trunco e descrizione di una pettorina di fanciullo singolare per varie anom. Mem. R. Accad. Sci. Istituto di Bologna. S. 2. 7:383-393.

Calori, L. (1868) Delle anomalie pìu importanti di ossa, vasi, nervi, e muscoli occorse nell'ultimo biennio facendo anatomia del corpo umano. Mem. R. Accad. Sci. Istituto di Bologna S.2., 8: 417-482.

Carrel, -. (1872) Biceps huméral trifide. Lyon Méd. 10:43-44.

Chevalier, -. (1876) Biceps à trois chefs. Lyon Méd. 21:474.

Cogniard, -. (1874) Biceps à trois chefs. Lyon Méd. 15:500.

Curnow, J. (1873) Notes of some irregularities in muscles and nerves. J. Anat. Physiol. 7:304-309.

Debierre, C. (1888) Sur le biceps brachial a trois chefts. Soc. Biol. Comptes Rendus Hebdomadaires des Séances et Mémories. 40:486-489.

Deaver, J.B. (1888-89) Anatomical: Forty-seven anomalies of the biceps muscle. Univ. Med. Magazine Philadelphia 1:110.

Ferner, H. (1938) Der nervus musculocutaneus, seine Verlaufsvarietäten an Oberarm und deren Beziehungen zur Entwicklung eines Caput tertium bicipitis. Z. Anat. Entwicklungsgesch. 108:567-586.

Franceschini, P. (1926) Sulle inserzioni terminali del M. bicipte nell'uomo. Arch. Ital. di Anat. e di Embryologia 23:714-735.

Greig, H.W., Anson, B. J. and J.M. Budinger. (1952) Variations in the form and attachments of the biceps brachii muscle. Q. Bull. Northwestern Med. School 26:241-244.

Groeneveld, G. Über einen M. biceps brachii mit fehlender Sehne. Anat. Anz. 63:358-361.

Gruber, W. (1872) Sur un muscle biceps humeral ayant une portion coracoidienne et une portion humeral anomaleè la place de la portion glenoidienne. Bull. l'Acad. Imp. Sci. St. Petersbourg 17:314-318.

Herve, G. (1883) Anomalie du muscle biceps brachiale. Bull. Soc. d'Anthropol. de Paris S.3 6:40-46.

Herve, G. (1889) Variations correlatives: biceps à quarte chefs, trajet dévié du nerf musculo-cutané. Bull. Soc. d'Anthropol. de Paris 12:405-410.

Hill, N.A., Howard, F.M. and B.R. Huffer. (1985) The incomplete anterior interosseous nerve syndrome. J. Hand Surg. A 10:4-16.

Jackson, C.M., Ed. (1932) Morris' Human Anatomy, P. Blakiston's Son & Company, Philadelphia.

Joessel, J.G. (1877) Beiderseit Fehlen des langen Bicepskopfes. Z. Anat. Entwicklungsgesch. 1877:143.

Khaledpour, C. (1985) Über Anomalien des M. biceps brachii. Anat. Anz. 158:79-85.

Kopuz, C., Sancack, B. and S. Ozbenli. (1999) On the incidence of the third head of biceps brachii in Turkish neonates and adults. Acta Anat. Nippon 74(3):301-305.

Kosugi, K., Shibata, S. and H. Yamashita. (1992) Supernumerary head of biceps brachii and branching pattern ofthe musculocutaneous nerve in Japanese. Surg. Rad. Anat. 14:(2):175-185.

Kudo, K. and K. Bando (1956) Varietäten-Statistik des M. biceps brachii beim nordchinesischen Weibe. Okajimas' Folia Anat. Jpn. 28:299-301.

Laha, R.K., Lunsford, D. and M. Dujorny (1978) Lacertus fibrosus compression of the median nerve. J. Neurosurg. 48:838-841.

Lecco, T.M. (1907) Ein Fall von vollständigem Fehlen des langen Kopfes des M. biceps brachii und damit in Zusammenhang stehen den Veränderungen an Knochen und Gelenkteilen. Anat. Anz. 30:522-528.

Lenoir, O. (1901) Sur las signification des chefs accessories huméraux du biceps brachial. J. Anat. Physiol. Norm. pathol. de l'Homme et des animaux 37:309-311.

Macalister, A. (1875) Additional observations on muscular anomalies in human anatomy (third series), with a catalogue of the principal muscular variations hitherto published. Trans. Roy. Irish Acad. Sci. 25:1-134.

Meyer, A.W. (1914) Spolia Anatomica. J. Anat. Physiol. 48:107-160.

Miller, J.M.A., Trelease, R.B. (2014) Long head of the biceps brachii perforated by a duplicated musculocutaneous nerve. Int. J. Anat. Var. (IJAV) 7:62-64.

Miura, Y. (1956) Anatomical studies on the variations of the M. biceps brachii. Tokyo Jikeikai Ikadaigaku Kaibogaku Kyoshitsu Gyosekishu 14:5-20. In Japanese.

Mori, M. (1964) Statistics on the musculature of the Japanese. Okajimas Fol. Anat. Jap. 40:195-300.

Nakatani, T., Tanaka, S. and S. Mizukami. (1998) Bilateral four-headed biceps brachii muscles: The median nerve and brachial artery passing through a tunnel formed by a muscle slip from the accessory head. Clin. Anat. 11(3):209-212.

Odin, -. (1869) Faisceau supplémentaire du long chef du biceps et coraco-brachial surnuméraire sur le même bras. Lyon Med. 2:50.

Odin, -. et -. Albert. (1869) Faisceau supplémentaire du long chef du biceps brachial. Lyon Méd. 1:483.

Ohki, T., Abe, Y. and G. Sekisawa. (1958) On the supernumeral heads of the M. biceps brachii. Iwate Ikadaigaku Kaibogakukyoshitsu Gyosekishu. 5:93-97. In Japanese.

Pedraza, M.H. (1934) Principales anomalias musculares observadas en los anfiteatros de la Facultad. Revista de la Facultad de Medicina de la Universidad National, Colombia 3(2):75.

Pagenstecher, E. (1895) Ueber Sehnen und Muskelrisse am Musculus biceps brachii. Berliner Klinische Wochenschrift. 32:353-355.

de Pina, L. (1929) Atrophie de la longue portion du M. Biceps brachii (BNA). Bull. Mem. Soc. d'Anthropol de Paris 10:40-41.

Pires de Lima, J.A. (1914) Nova série de observacões Portuguesas de anomalias musculares. Arch. de Anat. e de Anthropol. 1:231-260.

Pires de Lima, -. (1923) Le portions surajontées du biceps brachial chez les Portugais. Comptes Rendus, Soc. Biol. 88:1329-1330.

Reid, R.W. and S. Taylor, (1879) Anatomical Variations. Reports. St. Thomas's Hospital 9:46-47.

Revol, -. (1873) Statistique sur le biceps huméral. Lyon Méd. 13:36.

Revol, -. (1874) Statistique sur le biceps huméral. Lyon Méd. 16:356.

Rodet, -. (1874) Biceps huméral à trois chefs. Lyon Méd. 16:356.

Santo Neto, H., Camilli, J.A., Andrade, J.C., Meciano Filho, J. and M.J. Marques. (1998) On the incidence of the biceps brachii third head in Brazilian white and blacks. Anat. Anz. 180(1):69-71.

Sargon, M.F., Tuncali, D. and H. H. Celik. (196) An unusual origin for the accessory head of biceps brachii muscle. Clin. Anat. 9(3):160-162.

Shah, M.A. and M. Shah. (1946) Quadricipital M. biceps brachii. J. Anat. 80:54.

Shepherd, F.J. (1880) Notes on abnormalities observed in the dissecting-room of McGill University, from October, 1875, to May, 1879. Annual Report. Montreal General Hospital 1:71-93.

da Silva Leal, M. (1926) Le fréquence des chefs surnuméraires du biceps brachiale chez les Portugais. Soc. Biol., Comptes Rendus 95:309-319.

da Silva Leal, M. (1926) Les chefs surnuméraires du biceps brachial chez les monstres tératencéphaliens. Sociéte de Biologie (et de ses filiales), Comptes Rendus (Hebdomadaires des Séances et Memories.) Tome II:1285-1286.

Soulas, A. et H. Valois (1913) Contribution à l'etude des anomalies du biceps brachial, douze cas de chefs surnumeraires. Montpellier Médical 36:217-222.

Spinner, M. (1970) Anterior interosseous nerve syndrome, with special attention to its variations. J. Bone Joint Surg, A 52:84-94.

Spinner, R.J., Carmichael, S.W., and M. Spinner. (1991) Partial median nerve entrapment in the distal arm because of an accessory bicipital aponeurosis. J. Hand Surg. A. 16:236-244.

Stolowsky, A. (1899) Drei seltene Anomalien des M. biceps brachii. Anat. Hefte 12:299-336.

Swieter, M.G. and S.W. Carmichael. (1980) Bilateral three-headed biceps brachii muscles. Anat. Anz. 148:346-349.

Takeshige, A., Miyazima, S., Minakawa, T., Hayashida, T., and K. Nakamura. (1960) Variation of the M. biceps brachii. Kurume Igakkai Zasshi. 23:865-868. In Japanese.

Tenchini,L. (1879) Anomalie del bicipite omerale. Gazzeta Medica Italiana: Provincie Venete.8 (4):31-33.

Testut, L. (1882) Signification anatomique du chef humeral du muscle biceps. Bull. Soc. d'Anthropol. de Paris 6:238-245.

Testut, L. (1884) Les anomalies musculaires chez les Negres et chez les blancs. Internat. Monatschrift Anat. Physiol. 1:285-291.

Warner, J.P., Palleta, G.A. and R.F. Warner. (1992) Accessory head of biceps brachii: Case Report demonstrating clinical relevance. Clin. Ortho. Res. 280:179-181.

Weil, -. (1869) Biceps humèral à quatre chefs. Lyon Med. 1:484.

Wolf-Heidegger, W. (1937) Contribution à l'étude des anomalies des muscles biceps brachial et brachial antérieur. Arch. d'Anat. d'Histol. et Embryol. 23:207-217.

Zagorsky, P. (1809) Observationés anatomicae de musculorem quorundam corporis humani varietate minus frequente. Memories de l'Academie Imperiale des Sciences de St. Petersbourg. T.1:355-359. (Akademiia Nauk SSSR....).

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