Side Contour of the Lateral Region of the Male Thorax

Description

Beginning just inferior to the clavicle, the infraclavicular fossa (Mohrenheim or Morenheim’s fossa) is visible as a shallow depression between the anterior border of pectoralis major and the deltoid, tapering medially toward the sternoclavicular region. Along the lateral thoracic wall, the curved contours of ribs and intercostal spaces read through the overlying pectoral and serratus anterior muscle planes, continuing inferiorly toward the costal margin. Posteriorly, the silhouette transitions toward the latissimus dorsi and the lateral border of the scapular region. Clean surface anatomy. Clinically, this side contour matters because Mohrenheim’s fossa overlies the deltopectoral groove and the cephalic vein, a frequent site for venous access and a landmark used when developing the deltopectoral approach for shoulder and proximal humerus surgery. The same lateral thoracic sweep also helps orient palpation of rib levels when assessing rib fractures, intercostal muscle strain, or planning chest tube placement relative to the midaxillary line and the “safe triangle” boundaries. Useful for gross anatomy and surface anatomy teaching in medical and physical therapy curricula, as well as for atlas plates or clinical skills manuals covering thoracic landmarks, deltopectoral access, and lateral chest wall examination. Anatomical accuracy verified by SciePro's Medical Advisory Board.