Fig. 2.

Exemplar waveforms of forces exerted at the tendons of SO and $\text{LG}+\text{PL}$. Passive and total forces at soleus distal (SO), $\text{LG}+\text{PL}$ proximal ($\text{LG}+\text{PL}$ prox) and $\text{LG}+\text{PL}$ distal ($\text{LG}+\text{PL}$ dist) tendons were measured simultaneously before (passive) and during (active) tetanic contraction. Gray areas indicate the 50 ms time-windows for extraction of forces during passive and active state of muscles. Mechanical interaction between SO and $\text{LG}+\text{PL}$ is noticeable in the first portion of SO relaxation, which is much quicker than what can be expected from the slow SO muscle fibers and, thus, attributed to relaxation of the faster $\text{LG}+\text{PL}$ muscle fibers