The sternalis muscle (musculus sternalis) is the name usually
given to this common anatomical variant, but the terms
‘episternalis’, ‘presternalis’, ‘sternalis brutorum’, ‘rectus
thoracis’, ‘rectus sterni’, ‘superficial rectus abdominis’ and
‘japonicus’ have also been used in the literature (for reviews
see Le Double, 1879; Calori, 1888; Pichler, 1911; Blees,
1968). According to Turner (1867), Cabrolius was the first,
in 1604, to describe sternalis. Nevertheless this muscle is
often unknown even in clinical practice (Bailey & Tzarnas,
1999; Vandeweyer, 1999).
Thus far, investigations on the incidence of sternalis have
been made both in large populations such as the American
(Barlow, 1935) and small populations, for example in
Taiwan (Shen et al. 1992; Jeng & Su, 1998). In Europe, all
studies on the frequency of this muscle have been made
amongst subpopulations in Western (e.g. Cunningham,
1888; Le Double, 1890, 1897) and Northern Europe
(Gruber, 1860) although the reported frequencies have been
quite different. There is a lack of information about sternalis
in Eastern European populations. We therefore present
data from a study on the incidence of sternalis muscle in
Bulgaria.