CC BY-NC-ND 4.0 · Int J Sports Med 2023; 44(09): 673-679
DOI: 10.1055/a-2044-4805
Orthopedics & Biomechanics

Vertical and Leg Stiffness Modeling During Running: Effect of Speed and Incline

1   Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
2   Department of informatics, University of Oslo Faculty of Mathematics and Natural Sciences, Oslo, Norway
,
Mathieu Falbriard
3   Laboratory of Movement Analysis and Measurement (LMAM), EPFL, Lausanne, Switzerland
,
Kamiar Aminian
3   Laboratory of Movement Analysis and Measurement (LMAM), EPFL, Lausanne, Switzerland
,
Gregoire P Millet
1   Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
› Author Affiliations
Funding Information Innosuisse – Schweizerische Agentur für Innovationsförderung — http://dx.doi.org/10.13039/501100013348; 32166.1

Abstract

A spring mass model is often used to describe human running, allowing to understand the concept of elastic energy storage and restitution. The stiffness of the spring is a key parameter and different methods have been developed to estimate both the vertical and the leg stiffness components. Nevertheless, the validity and the range of application of these models are still debated. The aim of the present study was to compare three methods (i. e., Temporal, Kinetic and Kinematic-Kinetic) of stiffness determination. Twenty-nine healthy participants equipped with reflective markers performed 5-min running bouts at four running speeds and eight inclines on an instrumented treadmill surrounded by a tri-dimensional motion camera system. The three methods provided valid results among the different speeds, but the reference method (i. e., Kinematic-Kinetic) provided higher vertical stiffness and lower leg stiffness than the two other methods (both p<0.001). On inclined terrain, the method using temporal parameters provided non valid outcomes and should not be used. Finally, this study highlights that both the assumption of symmetry between compression and decompression phases or the estimation of the vertical displacement and changes in leg length are the major sources of errors when comparing different speeds or different slopes.



Publication History

Received: 01 February 2023

Accepted: 01 February 2023

Accepted Manuscript online:
28 February 2023

Article published online:
01 June 2023

© 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Georg Thieme Verlag
Rüdigerstraße 14, 70469 Stuttgart, Germany