Anterior Scalene
The scalenes vary in the degree of their costal and vertebral attachments, as well as their interrelationship caused by the fusion of numerous fascicles. A problem of definition has been compounded by the authors who ascribe various muscles to different parts of the scalene muscle mass. Frequently (about 30% of cases studied) a poorly defined muscle mass is present.
A scalenus minimus (intermedius (Testut), pleuralis [LeDouble]) may originate from the anterior tubercle of the sixth and seventh cervical vertebrae and inserts on the first rib (behind the subclavian groove). It may also join the pleural cupula through a suprapleural membrane. When this muscle is not present, a connective tissue band is found. Typically the anterior scalene arises from the fourth, fifth, and sixth cervical vertebrae (anterior tubercles). The muscle may also arise from the third, and rarely from the seventh. When the anterior scalene is doubled, one of the two muscles is referred to as the accessory anterior scalene. Anterior scalene may fuse with prevertebral muscles. Anterior scalene is often pierced or divided by the brachial plexus and / or the subclavian artery.
Syn.: m. scalenus anticus, scalenus prior (Albinus), scalenus primus (Krause).
References
Bochdalek, Jr. (1867) Vor dem Musculus scalenus anticus ihren Verlauf nehmende Art. subclavia dextra. Arch Path. Anat. Physiol. Klin. Med. 41:261-263.
Boyd, G.I. (1933-34) Abnormality of the subclavian artery associated with the presence of the scalenus minimus. J. Anat. 68:280-281.
Fawcett, E. (1896) What is Sibson's muscle (scalenus pleuralis)? J. Anat. Physiol. 30:433-436.
Gilis,P. (1891) Note sur l'anatomie des muscles scalènes. Soc. Biol., Comptes Rendus Hebdomadaires des Séances et Mémories. 43:223-226.
Lazorthes, G. et A.Haumont. (1952) La boutonnière scalénique (scalène antérieur, petit scalène). L'Assoc. Anatomistes., Comptes Rendus. 39:312-315.
LeDouble, A.F. (1897) Traité des variations du Système Musculaire de l'Homme et Leur Signification au Point de Vue de l'Anthropologie Zoologique. Libraire C. Reinwald, Schleicher Freres, Paris.
Livini, F. (1908) Osservazioni anatomische e considerazioni critiche intorno al M. scaleno nell'uomo. Arch. Ital. Anat. Embriol. 7:1-17.
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.
Nat, B.S. (1924) The scalenus muscle. J. Anat. 58:268-270.
Sebileau, P. (1891) Le muscle scalène. Soc. Biol., Comptes Rendus Hebdomadaires des Séances et Mémoires. 43:201-221.
Shore, L.R. (1926) An example of the muscle scalenus minimus. J. Anat. Physiol. 60:418-419.
Stott, C.F. (1928) A note on the scalenus minimus muscle. J. Anat. 62:359-361.