An examination of Fröhlich's theory of the treppe

Abstract

It is commonly believed that during the treppe a muscle possesses a progressively augmented power of performing work. According to Fröhlich, the augmentation is not real but only apparent. He believes that fatigue of the muscle elements begins with the beginning of the series of contractions, and that, from the first, it is manifested by a slowing of relaxation, a diminution in the extent of contraction, and a diminution in irritability. Successive elements of a stimulated muscle contract successively and those first in contraction begin their relaxation before later elements have reached the maximum of shortening. Since the total amount of shortening of the whole muscle represents the algebraic sum of the amounts of shortening of the several elements, with the slowing of relaxation, the total amount of shortening is increased. This more than counterbalances the diminution in the extent of contraction. The treppe is thus a physical expression of delayed vital processes and signifies a diminished, rather than an increased working power. Fröhlich has extended this theory to the augmentation observed in the preliminary stages of the action of cold, asphyxia, carbon dioxide, alcohol and other narcotics on various tissues, in the central nervous system under various conditions, in the current of action of nerves, and even in the production of heat in fevers.