Exploring the soleus muscles
The soleus muscles are part of the group of muscles that move the foot and ankle. This muscle and the gastrocnemius muscles are good friends and even better working partners. Their tendinous attachment to the calcaneus (heel bone) form the very strong Achilles tendon. Interestingly, soleus is sometimes referred to as the second heart, as the contractions of this muscle play an important role in helping blood get back to the heart.
What does the name of the soleus muscles mean?
The name soleus comes from the Latin word “solea” meaning sandal or flat of the foot. It also refers to “sole”, a type of flat fish.
Where do the soleus muscles attach?
The soleus muscle is part of the posterior compartment of the leg. They are located deep to the gastrocnemius. Specifically, soleus originates on the soleal line of the tibia and on the head of the fibula.
It inserts on the calcaneus via the Achilles tendon, which is sometimes known as the calcaneal tendon.
What actions do the soleus muscles do?
You’ll notice that the soleus muscle only crosses the ankle joint, so its actions will only act on that joint.
The soleus is responsible for plantarflexion of the ankle. It’s the strongest plantarflexor.
Poses where this muscle contracts
Whenever we are plantarflexing our foot against a resistance this muscle will contract. A posture such as purvottanasana requires us to strongly contract these muscles in an effort to flatten the bottom of our foot against the floor.
Shalabasana also asks us to contract these muscles, however, the resistance is just the weight of our foot and working against gravity.
Poses where this muscle is lengthened
Lengthening the soleus muscles is easily found in downward facing dog. Because of the dorsiflexion that happens in that position, we passively stretch these muscles.
If we lower down in a posture like utkatasana, these muscles are getting longer, but they are doing an eccentric contraction as we move into it. They’re lengthening and contracting to moderate the movement.