Series elasticity of the human triceps surae muscle: measurement by controlled-release vs. resonance methods

With a newly developed Controlled-Release Ergometer the complete characteristic of the series elastic component can be measured in human muscles. Previous estimates were based on the resonance method: muscle elasticity was assessed from the resonance frequency of the muscle elasticity connected to a known mass. In this study both methods have been compared. It turns out that the resonance method gives elasticity values of the correct order of magnitude, but that it is not accurate enough to provide individual data or indications on the course of the series elastic characteristic of the human ankle plantarflexors (m. triceps surae)