The anatomy of thoracic outlet structures is complex in several ways. First, many of the bones are both origin and insertion for muscles. Second, several of the muscles have statistically significant variations in cadaver studies. Here, you will find a brief overview of Thoracic Outlet Syndrome followed by a walk-through of the structures from back […]
The anatomy of the extrinsic chest muscles is more complicated than the first glance suggests. They originate on the front of the axial skeleton and insert on the upper extremity. Generally speaking, they protract the scapula and draw the humerus toward the midline. This arrangement gets a little more complicated with the pectoralis major. The
The subclavius is a short, thick triangular muscle along the inferior aspect of the clavicle. Origin – first rib Insertion – medial clavicle. Function – lowers clavicle. The origin is a flat tendon that attaches on the first rib, near the sternal cartilage. It gradually transitions to muscle fibers. The insertion is a tendon that
Overview The serratus anterior has complex and variable anatomy. It is a broad, flat muscle with multiple bellies. It usually has eight sections, connecting the scapula’s vertebral border to each of the first eight ribs. Therefore, this structure makes it an extrinsic chest muscle. It is on the lateral trunk, under the scapula, extending like
Overview Pectoralis minor is a fan-shaped muscle in the front of the shoulder. Notably, its anatomy has frequent variations. Basically, it secures the coracoid process of the scapula to the rib cage. Superficially, the pectoralis major covers the pectoralis minor. Overview of Pectoralis Minor Anatomy Origin Insertion Function Innervation Anomalies are clinically significant on attachments and innervation.
Here, you will find the anatomy of the pectoralis major, including functional considerations, variations and links to related posts. Overview The Pectoralis major is a large, flat muscle on the anterior thorax. It originates on the anterior axial skeleton. Then, with a twist, it inserts on the proximal humerus. Origin Insertion Function Nerve The extensive
