A simple method for measuring stiffness during running.

Abstract : The spring-mass model, representing a runner as a point mass supported by a single linear leg spring, has been a widely used concept in studies on running and bouncing mechanics. However, the measurement of leg and vertical stiffness has previously required force platforms and high-speed kinematic measurement systems that are costly and difficult to handle in field conditions. We propose a new "sine-wave" method for measuring stiffness during running. Based on the modeling of the force-time curve by a sine function,this method allows leg and vertical stiffness to be estimated from just a few simple mechanical parameters: body mass, forward velocity, leg length, flight time, and contact time. We compared this method to force-platform-derived stiffness measurements for treadmill dynamometer and overground running conditions, at velocities ranging from 3.33 m.s-1 to maximal running velocity in both recreational and highly trained runners. Stiffness values calculated with the proposed method ranged from 0.67 % to 6.93 % less than the force platform method, and thus were judged to be acceptable. Furthermore, significant linear regressions (p < 0.01) close to the identity line were obtained between force platform and sine-wave model values of stiffness. Given the limits inherent in the use of the spring-mass model, it was concluded that this sine-wave method allows leg and stiffness estimates in running on the basis of a few mechanical parameters, and could be useful in further field measurements.
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Journal articles
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https://hal.univ-cotedazur.fr/hal-01859288
Contributor : Jean-Benoit Morin <>
Submitted on : Tuesday, August 21, 2018 - 9:05:43 PM
Last modification on : Thursday, July 11, 2019 - 10:09:06 AM

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  • HAL Id : hal-01859288, version 1
  • PUBMED : 16082017

Citation

Jean Benoît Morin, Georges Dalleau, Heikki Kyröláinen, Thibault Jeannin, Alain Belli. A simple method for measuring stiffness during running.. Journal of Applied Biomechanics, Human Kinetics, 2005, pp.167-80. ⟨hal-01859288⟩

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