Insights into muscle metabolic energetics: Modelling muscle-tendon mechanics and metabolic rates during walking across speeds
Fig 2
Metabolic rates in the soleus at different levels of muscle activations during shortening, isometric, and concentric contractions (first row), and metabolic (), work (
), and heat (
) rates during walking (second and thrid row).
Metabolic rates were computed using six models: Umberger et al. [14] (UM03), Bhargava et al. [12] (BH04), Houdijk et al. [15] (HO06), Lichtwark and Wilson [16] (LW07), Umberger [17] (UM10), and Uchida et al. [18] (UC16). The ratio of slow twitch muscle fiber, muscle mass, optimal fiber length, and maximum voluntary contraction is assumed as 0.8, 0.48 kg, 4.5 cm, and 10 [optimal fiber lengths/second], respectively. Simulated muscle metabolic rate as computed from one representative subject walking at preferred speed.