Tensile tests on a muscle: Influence of experimental conditions and of velocity on its passive response

Paper in proceeding, 2012

Muscle mechanical properties are necessary to improve numerical models of the human body. They have been assessed for animal muscles in studies performed in various experimental conditions. These different experimental protocols may have an influence on muscle response. The aim of this study was thus to evaluate the effect of testing conditions as well as velocity on the passive response of a muscle. Tensile tests at 1 mm.s -1, 10 mm.s -1 and 100 mm.s -1 were performed on a dog muscle in ambient conditions, immersion in 22°C saline solution and immersion in 35°C saline solution. Maximum load Fmax and final stiffness K were measured. The influence of velocity and of experimental conditions on these parameters was studied statistically. The parameters were not very sensitive to changes in velocity (increase of 5% for Fmax between 1 mm.s -1 and 100 mm.s -1). Nevertheless, they were sensitive to experimental conditions (decrease of 25% for Fmax between ambient conditions and immersion in heated saline solution). Consequently, the experimental conditions have an influence on muscle passive response and must be taken into account in the definition of the mechanical properties used in modeling.