How does the rib cage move during inhalation and exhalation

During inhalation the ribs lift upward and outward (bucket-handle movement) and the sternum moves anteriorly (pump-handle movement), increasing the thoracic cavity volume. This downward movement of diaphragm and expansion of rib cage reduces intrathoracic pressure, drawing air in. During exhalation the mechanism reverses: ribs move downward and inward, sternum moves posteriorly, thoracic volume decreases and air is expelled.