出版社：Japan Society of Physical Education, Health and Sport Sciences
摘要：An attempt was made to investigate three-dimensional box reation forces applied to the pole-tipduring pole vaulting, and to idenfify technical factors necessary for increasing the maximal height of center of gravity (C.G.) based on the pole-chord reaction forces (henceforth, PCF). The subjects (five pole vaulters and four decathletes) performed pole vaults to clear the cross bar set at a height of 82-93% of their personal best record. All trials were videotaped with four video cameras (60 fps), and box reaction forces (500Hz) were measured with a Kistler force platform on which a specially made vaulting box was bolted. Three-dimensional coordinates of points on the vaulting poles and body landmarks of vaulters were obtained using a DLT procedure. Impulse and PCF were calculated from the forces and coordinate data. Force exerted via the lower hand (henceforth, F_) was calculated by solving equations of motion for the pole segment between the hands. For simplicity, the mass and moment of inertia of the pole segment were assumed to be zero. The horizontal impulse of box reaction forces in the pole-bending phase and verticalimpulse in the pole-straightening phase were significantly related to the maximal C.G.height (r=-0.701, p<0.05 and r=0.688, p<0.05, respectively). These impulses were significantly related to the PCF in each vaulting phase (r=-0.888, p<0.01 and r=0.981, p<0.001, respectively). Three PCF patterns were found: Type A, in which PCF during the pole-straightening phase exceeded that during the pole-bending phase; Type B, in which the pattern of Type A was reversed; Type C, in which the PCFs during both phases were almost equal. It has been suggested by some researchers that bending and straightening moments applied to the pole by F_ influence the magnitude of pole-bending and the PCF. Type A subjects exerted F_ in a pushing direction (applied bending moment) during the pole-bending phase, and in a pulling direction (applied straightening moment) during the pole-straightening phase. The lower hand technique shown in Type A seemed more appropriate for increasing the maximal C.G. height, because (1) the vaulter was able to use a higher grip height due to the increased magnitude of pole-bending, and (2) the vertical impulse of the box reaction force was increased due to enhancement of PCF in the pole-straightening phase.
其他摘要：An attempt was made to investigate three-dimensional box reation forces applied to the pole-tipduring pole vaulting, and to idenfify technical factors necessary for increasing the maximal height of center of gravity (C.G.) based on the pole-chord reaction forces (henceforth, PCF). The subjects (five pole vaulters and four decathletes) performed pole vaults to clear the cross bar set at a height of 82-93% of their personal best record. All trials were videotaped with four video cameras (60 fps), and box reaction forces (500Hz) were measured with a Kistler force platform on which a specially made vaulting box was bolted. Three-dimensional coordinates of points on the vaulting poles and body landmarks of vaulters were obtained using a DLT procedure. Impulse and PCF were calculated from the forces and coordinate data. Force exerted via the lower hand (henceforth, F_) was calculated by solving equations of motion for the pole segment between the hands. For simplicity, the mass and moment of inertia of the pole segment were assumed to be zero. The horizontal impulse of box reaction forces in the pole-bending phase and verticalimpulse in the pole-straightening phase were significantly related to the maximal C.G.height (r=-0.701, p<0.05 and r=0.688, p<0.05, respectively). These impulses were significantly related to the PCF in each vaulting phase (r=-0.888, p<0.01 and r=0.981, p<0.001, respectively). Three PCF patterns were found: Type A, in which PCF during the pole-straightening phase exceeded that during the pole-bending phase; Type B, in which the pattern of Type A was reversed; Type C, in which the PCFs during both phases were almost equal. It has been suggested by some researchers that bending and straightening moments applied to the pole by F_ influence the magnitude of pole-bending and the PCF. Type A subjects exerted F_ in a pushing direction (applied bending moment) during the pole-bending phase, and in a pulling direction (applied straightening moment) during the pole-straightening phase. The lower hand technique shown in Type A seemed more appropriate for increasing the maximal C.G. height, because (1) the vaulter was able to use a higher grip height due to the increased magnitude of pole-bending, and (2) the vertical impulse of the box reaction force was increased due to enhancement of PCF in the pole-straightening phase.
关键词：棒高跳;ボックス反力;ポール弦反力;技術的要因;-
其他关键词：pole vault ; box reaction force ; pole-chord reaction force ; technical factors
