Characteristics of the arterial distribution to the infraspinatus: Relationships between gross anatomical observations and clinical signs

Abstract

[Purpose] The arteries supplying the infraspinatus muscle were observed using a gross anatomical technique to improve clinical evaluation of shoulder symptoms. [Subjects and Methods] We examined 19 upper extremities of 17 adult cadavers to observe the course and distribution of arteries supplying the infraspinatus muscle. [Results] The suprascapular and circumflex scapular arteries were major arterial sources of the muscle, and ran on the deep surface of the muscle. In some cases, the suprascapular artery ran through a tunnel consisting of the superior transverse scapular ligament and scapular notch, before reaching the muscle. The area of distribution of the two arteries varied among cases. [Conclusion] This study revealed that the arteries supplying the infraspinatus muscle are liable to compression because of their course deep to the muscle and through a tunnel. Moreover, variation in arterial distribution among individuals may affect various clinical signs.