Performing plantarflexion with a bent knee position, and slower speeds appears beneficial for the soleus.
In practice,
performing plantarflexion with faster speeds may be beneficial for training the gastrocnemius while utilising slower speeds may be more beneficial for the soleus.
They report that when
performing plantarflexion with the knee fully extended, the medial and lateral gastrocnemius displayed superior peak muscle activity with increasing angular velocity, while the soleus displayed decreasing peak muscle activity with increasing velocity.
They report that the medial gastrocnemius displayed superior muscle activity when
performing plantarflexion with an extended knee position, while the soleus displayed superior muscle activity with the leg bent.
Not exact matches
Therefore, it appears that during dynamic
plantarflexion with an extended knee position preferentially targets the gastrocnemius, while
performing plantar flexion with a flexed knee preferentially targets the soleus muscle.