Final answer:
The shaft is the most commonly fractured part of a rib, being most susceptible to injury due to its elongated shape and curvature.
Step-by-step explanation:
The most commonly fractured part of a rib is the shaft.
Ribs are essential components of the thoracic cage and are numbered 1-12 corresponding to the thoracic vertebrae. Each rib consists of several parts, including the head, neck, tubercle, and shaft. The shaft is the elongated part of the rib, which is most susceptible to fractures. This area experiences the greatest degree of curvature at the angle of the rib, making it more prone to injury. The angles of the ribs form the most posterior extent of the thoracic cage and align with the medial border of the scapula.
The most commonly fractured part of a rib is the shaft. Each rib consists of several parts, including the head, neck, tubercle, and the shaft, also known as the body of the rib. The head of the rib articulates primarily with the costal facet located on the body of the same numbered thoracic vertebra.