Professor, National Taiwan Normal University, Taipei,
(Received 29 April 1997; accepted 31 October 1997)
Falling from a height, usually from a building, occurs ordinarily in suicide, in some accidents, and sometimes as an act of homicide. The point of trajectory, the horizontal distance and the impact point are closely related to the initial velocity, angle and height. This study examines the falling pattern in order to determine the mental status of the jumper as well as the manner of death. Initial velocity is found using horizontal movement and height. A serial study of athletes performing both the running jump (long jump) and standing jump (swimmer's start jump) via biomechanical methods is described. The initial velocity of the running jump and standing jump in normal athletics is 9.15 and 2.70 m/s with initial jumping angles of 21 and 38 deg, respectively. The maximal horizontal velocity of 9.15 m/s is closely related to maximal strength of initial velocity, angle of engaged force, and height. Theoretical estimation of the initial velocity between 2.70 and 9.15 m/s is correlative with the unique initial velocity and running jump to fall from a height that is closely related to the voluntary and attempted jump. Hence, the jumping victim with an initial velocity higher than 2.70 m/s implies suicide. These results indicate that horizontal distance and height are legitimate measures to use in speculating on the falling pattern and the manner of death. A unique case of suicide involving a run and jump with initial velocity greater than 2.70 m/s is illustrated.
Paper ID: JFS14304J