The motions of the landing leg preceding the support phases of the hop, step, and jump, thought to be important in the triple jump, are described. Film analysis of 16 elite male triple jumpers competing in the 1986 and 1987 TAC (U.S. national) Championships showed that backward sweeping, or “active,” landings were used prior to each support phase. A mathematical model showed that muscle action reduced the forward horizontal velocity of the landing foot during each landing. There were no statistically significant correlations of measures of landing leg motion with measures of performance. The landing prior to the jump phase was less active than the two preceding landings. However, the elite athletes in the present study were much more active in this landing than athletes of lesser ability. There was also some indication among the subjects of this study that activeness in this landing was associated with long triple jumps. Thus, activeness in this landing appears to be desirable but very difficult to achieve and/or use effectively.
Timothy J. Koh is with the Biomechanics Section, Dept. of Musculoskeletal Research, The Cleveland Clinic Foundation, Cleveland, OH 44106. James G. Hay is with the Biomechanics Lab, Dept. of Exercise Science, University of Iowa, Iowa City, IA 52242.