Accurate Morphological Classifications of the Semispinalis Capitis Neck Muscle

The semispinalis capitis muscle, found in the posterior neck of humans, is also known as the biventer cervicis. The majority of anatomy textbooks and atlases depict this muscle as containing two bellies of muscle with a horizontally linear intervening white tendonous band that neatly separates the muscle into upper and lower parts. In our dissection of seventy‐two semipsinalis capitis muscles, we found that it in no cases did it ever appear as commonly depicted in most anatomy books with a horizontal intervening tendon. Instead we found its tendon consists of multiple different parts that are commonly disconnected and lie either superior or inferior to each other in three different categories. The three main classifications include two uniform vertical bands, one vertical with one curved band, and an other group. We found that 54.2 percent falls in the two uniform vertical band classification, 26.4 percent falls in the one vertical one curved band classification, and 19.4 percent falls in the other classification. We encourage others to accurately drawn this muscle in anatomical textbooks.