Soleus
| Pronuncation | SOLE-ee-us |
| Derivation | Referring either to the sole of the foot, on which this muscle acts, or the sole fish, which its shape resembles. |
| Origin | Posterior surfaces of tibia and fibula. |
| Insertion | Via the Achilles tendon to the bone of the heel. |
| Action | Same as gastrocnemius; straightens the joint of the ankle, either pointing the foot, or lifting a standing figure onto the ball of the foot. |
Soleus underlies gastrocnemius and assists with its movement. It appears on either side of the Achilles tendon, visible as a distinct form on both medial and lateral sides of the leg. On both sides it is one of the columnar bands on the leg.
From the back, soleus continues the curve of gastrocnemius towards the heel, while the Achilles tendon pops up in relief on top of it.
On the medial side of the leg, flexor digitorum longus may be seen as a short bulk below soleus when it is working to curl the toes.