The relationship between emphysema and the sternocleidomastoid muscle size studied with voluntarily donated cadavers

Abstract

Activity of the sternocleidomastoid muscle, as one of the accessory inspiratory muscles, becomes remarkable when pulmonary diseases patients need muscular support for respiration in addition to the diaphragm. The present study inspected the relationship between the stages of emphysema and the size of sternocleidomastoid muscles with 42 voluntarily donated cadavers (average age 85.0 years). Severity of emphysema was evaluated by observation under a microscope, and by measurement of the long axis of pulmonary alveoli. The ratio of sectional areas of the sternocleidomastoid muscles to that of biceps brachii muscles was calculated, and was compared with the severity of emphysema for each cadaver. Among the female group with pulmonary diseases as the cause of death, the severity of emphysema showed a significant correlation to the sectional area ratio of sternocleidomastoid vs. biceps brachii muscles. This correlation was more obvious in women compared to men. This data suggests that the severity of emphysema can be predicted by observing the sternocleidomastoid muscles on the patients' body surface.