DAPENA, JESÚS and TERESA BRAFF. Use of separate hand locations to calculate ground reaction force exerted on a vaulting pole.Med Sci. Sports Exerc., Vol. 15, No. 4, pp. 313–318, 1983. A model was developed to permit calculation of the force exerted by the ground on a vaulting pole given the flexibility characteristics of the pole, the grip height of the upper hand, and the coordinates of each of the two hands relative to the base of the pole. The flexural rigidity of the pole was assumed constant throughout the length of the pole and not subject to hysteresis or dynamic loading effects. The model was based on the following rationale: knowing the initial angle of the base of the pole (β0) and the force vector (F1) exerted by the ground on the pole, it was possible to estimate the shape of the pole and the coordinates of the two hands following an iterative procedure. Conversely, it was possible to find a combination of β0, and F1that made the pole fit two specified hand locations.