What rib motion occurs during respiration for ribs 1-5?

During respiration, ribs 1-5 exhibit a specific type of motion known as pump handle motion. This motion is characterized by the movement of the anterior aspect of the rib cage, where the upper ribs (ribs 1-5) elevate and move forward during inhalation. The term "pump handle" effectively describes this action, as it resembles the motion of a handle being pumped down and up.

When engaging in deep breathing, as the diaphragm contracts and descends, it creates a negative pressure in the thoracic cavity, allowing the rib cage to expand. The elevation of ribs 1-5 not only increases the volume of the thoracic cavity but also enhances the capacity for airflow into the lungs. This action is particularly important in the mechanics of breathing, as it allows for an increase in lung volume and efficiency of gas exchange.

In contrast, other types of rib motions are more characteristic of different regions and functions. For example, bucket handle motion primarily involves the motion of the lower ribs (ribs 6-12) laterally and is more associated with the lateral expansion of the rib cage. Caliper motion refers to a lateral motion more relevant to the floating ribs. Rotational motion is generally not a primary mechanism utilized during normal