Ground reaction forces were obtained for the three phases of the triple jump for four collegiate triple jumpers, two men and two women. A single force platform was used, which thereby required the subjects to execute three separate jumps to produce a single triple jump record. The vertical force records for each phase showed two peaks having magnitudes in the range of 7 to 12 times body weight (BW) and 3.3 to 5 BW, respectively. These magnitudes are substantially higher than has been reported by others for distance running, sprinting, and in some cases other jumps. The maximum horizontal forces act to decrease the velocity of the mass center, but to different degrees for the different subjects. The data show that for any phase of the jump there is considerable variability in the timing and magnitudes of the force records among the different subjects although general patterns are similar. The results suggest that the use of mean force data from a number of subjects may conceal important differences between the way individuals execute the jump.
This study was funded in part by a grant from the National Collegiate Athletic Association.
Direct all correspondence to Melvin R. Ramey, Human Performance Laboratory, University of California, Davis, CA 95616.