Abstract
We examined the nutrient arteries of the bilateral subscapularis muscles in 10 Japanese adult cadavers and obtained the following findings. The subscapularis muscles were supplied by many different arteries arising from the subclavian and axillary arteries; therefore, these muscles were classified into two types by origin and distribution pattern of the supplying arteries. In Type I (nine cases), the suprascapular (Ss) and superior subscapular arteries (Sss) supplied the upper half of this muscle, the subscapular, circumflex scapular (Cs) and thoracodorsal arteries supplied the lower half, the deep branch of transverse cervical artery supplied the portion near its origin, andt he posterior circumflex humeral and other arteries supplied the area near the insertion. Type II was identical to Type I except that it lacked an Ss artery. Type II muscle was found in 11 cases. A few of these arteries were distributed through the dorsal surface of the subscapularis muscle after running around the upper and lower margins of this muscle. These muscles were subdivided into three types. Type C muscle, supplied only by the Cs artery, was the most common, and found in nine cases. This was followed by Type A, supplied by Cs and Ss arteries, found in seven cases, and Type B, supplied by Cs and Sss arteries, in four cases. Sss and Cs were the main arteries of these muscles : the former supplied 27.4 % of the entire muscle and the latter 28.3%. The total number of arteries counted varied from five to 10, and the number most frequently observed (six cases) was eight.
