Reproducibility of energy parameters in the pole vault

When running on the level, muscles perform as much positive as negative external work. On a slope, the external positive and negative work performed are not equal. The present study analysed how the ratio between positive and negative work modifies the bouncing mechanism of running. Our goals are to: (1) identify the changes in motion of the centre of mass of the body associated with the slope of the terrain and the speed of progression, (2) study the effect of these changes on the storage and release of elastic energy during contact and (3) propose a model that predicts the change in the bouncing mechanism with slope and speed. Therefore, the ground reaction forces were measured on 10 subjects running on an instrumented treadmill at different slopes (from −9 to +9 deg) and different speeds (between 2.2 and 5.6 m s −1 ). The movements of the centre of mass of the body and its external mechanical energy were then evaluated. Our results suggest that the increase in the muscular power is contained (1) on a positive slope, by decreasing the step period and the downward movements of the body, and by increasing the duration of the push, and (2) on a negative slope, by increasing the step period and the duration of the brake, and by decreasing the upward movement of the body. Finally, the spring-mass model of running was adapted to take into account the energy added or dissipated each step on a slope.

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“…When running uphill, the lower limb acts like a pole in athletics (Schade et al, 2006). During the first part of contact (i.e.…”

Section: Change In the Energy Fluctuations Of The Commentioning

confidence: 99%

The rebound of the body during uphill and downhill running at different speeds

Dewolf

Peñailillo

Willems

2016

Journal of Experimental Biology

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“…Thus, the horizontal and vertical positions of the vaulter's CG might be over-or under-estimated, affecting the calculated push-off index. However, recording the vault at 50 Hz might not affect the results since such rate frequency was available to compute the mechanical energy of the vaulter (based on the complete body digitalization or on the CG positions) (Schade et al, 2000(Schade et al, , 2006Arampatzis et al, 2004) or available to compute the kinetics of the vault (Morlier and Mesnard, 2007). It seems that recording the movement at 50 Hz did not limit the main results of this study: the final height of the vaulter's CG was related to kinematics data at PS and not affected by particular muscle coordination.…”

Section: Tablementioning

confidence: 99%

Catapult effect in pole vaulting: Is muscle coordination determinant?

Frère

Göpfert

Hug

et al. 2012

Journal of Electromyography and Kinesiology

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“…This is especially so in the pole vault, where the pole shows large deformations and has a high potential to store and return energy throughout the vault and so the interaction between vaulter and vaulting pole strongly influences performance (Dillmann and Nelson, 1968;Lundberg, 1995, 1997;Schade et al, 2000Schade et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

“…It is well accepted that during the pole support phase, in addition to the approach run, the vaulter is not only able to add energy to the vaulter/pole system by means of muscular work, but also that a certain amount of mechanical energy is lost due to friction and deformation within the biological and mechanical system Schade et al, 2006). Especially the jump and the planting of the pole are believed to show considerable energy losses (Linthorne, 1994(Linthorne, , 2000Ekevad and Lundberg, 1997).…”

Section: Introductionmentioning

confidence: 99%