Twelve male 100-m freestyle swimmers were videotaped during the 1992 Olympic Games. Four cameras, two above water and two below, recorded the same stroke cycle of the swimmer at approximately the 40- to 45-m mark. The whole body and the recovering arms were digitized from the videotapes to recreate a complete stroke cycle. Body position variables and hand reaction forces (Schleihauf, 1979) were calculated. Swimmers were divided into elite and subelite groups based on their swimming velocity and were compared for differences in biomechanical variables. Elites used slightly lower hand forces while maintaining a higher propelling efficiency. Subelites had opposite rotations about the longitudinal axis of the body rather than symmetrical body roll. The elite swimmers were different from subelites in that their pulling patterns were more efficient and their body position was more streamlined. These variables assisted them in achieving faster swimming velocities without requiring higher propulsive forces.
Jane M. Cappaert is with United States Swimming, International Center for Aquatic Research, 1750 E. Boulder St., Colorado Springs, CO 80909. David L. Pease and John P. Troup were with U.S. Swimming at the time of the study. John Troup is now with Pfizer Pharmaceutical, CT. David Pease is now with the University of Otago School of Physical Education, Dunedin, New Zealand.