**3. Trunk rotation**

Trunk rotation is a complex movement that involves many joints. For example, during rotation to the three left events are shown as; 1) rib rotation with costotransverse posterior gliding on the rotating side, whereas anterior rotation of the rib and gliding are on the opposite side, 2) thoracic body that is elevated and depressed in each segment, and 3) vertical asymmetrical torsion. Upper thoracic spine can move like pure axial rotation as well as thoracolumbar and cervicothoracic rotation. However, sometimes movement of the upper and lower thoracic spines also co-move with lateral flexion or rotation. Thus, articular facet between high and low spines is a sliding movement (Grant, 2001; Lee, 2002).

In conclusion, the chest wall, which is composed of spine, sternum, and ribs, moves in synchronization, no matter whether it is lateral flexion, flexion, extension, or rotation. However, the quality of movement affects individual direction because the costovertebral joint makes contact with the vertebral body, so that lateral expansion is affected more than anterior movement. Whereas, the 2nd to 8th ribs connect to the sternum anteriorly, thus expanding the chest in an anterior direction with pumping handle or anterior and superior motion, as well as bucket handle with lateral and superior motion (Norkin & Levangie, 1992) that occur in regular breathing (Greenman, 1996).

The chest mobilization technique is preferred in cases of COPD or chronic lung disease, with the basic theory of mainly improving ventilation. In addition, aging, prolonged use of a ventilator and chronic illness with neuromuscular dysfunction also concern chest wall mobility.

Rib torsion, passive stretching, trunk rotation, back extension, lateral flexion and thoracic mobilization are practiced to improve chest flexibility.

Fig. 5. Pump-Bucket pattern of chest movement. (Greenman, 1996)
