Joined effects of pennation angle and tendon compliance on fibre length in isometric contractions: a simulation study.
The main purpose of this study was to investigate the joined behaviours of tendon and pennation angle during maximal isometric contractions. A musculotendon model of the human soleus muscle was simulated as a function of ankle joint position, which determines the soleus length. Analysis of the respective values of tendon length and pennation angle for various musculotendon lengths showed that the primary effects of tendon elasticity and pennation angle variation were to reduce the fibre length variations by absorption of the musculotendon lengthening. The efficiency of this reduction process was the highest at short soleus lengths and principally related to tendon length variations. Finally, it was suggested that the optimal solution for musculotendon actuators acting in high lengthening ranges were long tendon units and great pennation angles. The heuristic model used in this study highlighted the existence of some dynamic phenomena inside the actuator. However, it did not pretend to represent the overall complexity of the mechanical interactions between the different elements composing the soleus architecture.
Legreneur
P
P
Groupe Analyse du Mouvement, UFR STAPS, Université de Bourgogne, Dijon, France. legrene@univ-lyon1.fr
Morlon
B
B
Van Hoecke
J
J
D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008954:Models, Biological; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D013710:Tendons / Q000502:physiology*