July 21, 2019
They both are in the back part of the lower leg and attach across the back of the heel through the Achilles tendon. The soleus only crosses the ankle joint whereas the gastroc crosses both the ankle and the knee joint. Consequently, the gastroc will also be affected by knee position and in fact, if the knee is bent then the gastroc actually can't help point the toes. On the other hand, as mentioned in Part I, the soleus is always active in pointing the toes because it only crosses the ankle joint.