Yes, your ribs move when you breathe. This movement is a component of respiration, the simple act of moving air into and out of the lungs, achieved by changing the volume inside the chest cavity, which is primarily protected by the rib cage. Lungs are passive and lack muscles to pull air in. Instead, surrounding skeletal and muscular structures must expand the space to create a pressure difference that draws air inward. This mechanical expansion and contraction is powered by the coordinated motion of your ribs and the muscles attached to them.
The Physical Motion of the Rib Cage
The ribs move in two distinct patterns to ensure the entire thoracic cavity expands in three dimensions during inhalation.
The upper ribs (one through seven) utilize the “pump handle” mechanism. This movement involves the ribs and sternum swinging upward and forward, increasing the anterior-posterior diameter of the chest, making it deeper from front to back.
The lower ribs (eight through ten) employ the “bucket handle” mechanism, which increases the width of the chest. In this motion, the ribs swing upward and outward.
This coordinated movement expands the overall volume of the chest cavity, which lowers the pressure inside the lungs, allowing air to rush in from the atmosphere. During a passive exhale, the ribs simply reverse this motion, dropping down and inward as the chest cavity naturally recoils.
The Muscular Engine of Breathing
This complex rib movement is powered by specialized respiratory muscles. The diaphragm serves as the single most significant muscle for quiet breathing. It is a large, dome-shaped sheet of muscle located beneath the lungs, separating the chest cavity from the abdomen. When you inhale, the diaphragm contracts and flattens, moving downward into the abdominal space. This downward movement is responsible for the majority of the vertical volume increase in the chest.
The spaces between the ribs contain two layers of intercostal muscles that assist in outward expansion. The external intercostal muscles contract during inhalation, pulling the ribs up and out to facilitate the pump handle and bucket handle motions. During normal, quiet exhalation, both the diaphragm and the external intercostals simply relax, allowing the elastic recoil of the lungs and rib cage to push air out. For a forced, effortful exhale, the internal intercostals actively contract to pull the ribs down and inward, rapidly decreasing the chest volume.
Understanding Different Breathing Patterns
The visibility of rib movement depends on the specific breathing pattern a person is using.
Diaphragmatic breathing, often called deep or abdominal breathing, primarily uses the downward motion of the diaphragm. In this relaxed state, the movement is concentrated low in the torso, leading to a visible expansion of the abdomen rather than obvious motion of the upper ribs.
In contrast, costal breathing, also referred to as shallow or thoracic breathing, relies more on the intercostal muscles to lift the rib cage. This pattern makes the pump handle and bucket handle actions more pronounced, resulting in a noticeable rise and fall of the chest. While one pattern may appear more dominant, both the diaphragm and the intercostals are engaged in every breath to ensure the lungs receive the air they need. The variation simply reflects whether the breath is shallow or deep.