WAVE CHARACTERISTICS OF OLYMPIC BREASTSTROKE SWIMMERS

The purpose of this study was to investigate the wave characteristics of breaststroke swimming. Particular emphasis was accorded the questio n of whether modem breaststroke is ''flylike'' (referring to the butte rfly stroke) and whether ''waves'' travel along the body during the br eaststroke cycle. Selected body landmarks and the center of mass (CM) of 8 Olympic breaststroke swimmers were quantified. Fourier analysis w as conducted to determine the amplitude, frequency composition, and ph ase characteristics of the vertical undulations of the vertex of the h ead, shoulders, hips. knees, and ankles. The differences in phase betw een these landmarks for the first (H1) and second (H1) Fourier frequen cies were investigated to establish whether body waves traveled in a c audal direction. While the motion of the upper body was somewhat flyli ke, the velocity of the H1 wave from the hips to ankles was variable a mong subjects and, for all subjects, was too slow to be propulsive. Co ntrary to what one would expect, the range of vertical motion of the C M was inversely related to the range of hip vertical motion. The two h ighest placing subjects, based on preliminary heat times (S1 and S4), were distinguished by a large range of hip vertical motion and a small range of CM vertical motion.