Vertical and Leg Stiffness Modeling During Running: Effect of Speed and Incline
Int J Sports Med DOI: 10.1055/a-2044-4805A 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 wh...
Source: International Journal of Sports Medicine - Category: Sports Medicine Authors: Meyer, Fr édéric Falbriard, Mathieu Aminian, Kamiar Millet, Gregoire P Tags: Orthopedics & Biomechanics Source Type: research