Its other end forms a common tendon with the gastrocnemius muscle; this tendon is known as the calcaneal tendon or Achilles tendon and inserts onto the posterior surface of the calcaneus, or heel bone.
The plantaris muscle and a portion of its tendon run between the two muscles. Deep to it (farther from the skin) is the transverse intermuscular septum, which separates the superficial posterior compartment of the leg from the deep posterior compartment.
On the other side of the fascia are the tibialis posterior muscle, the flexor digitorum longus muscle, and the flexor hallucis longus muscle, along with the posterior tibial artery and posterior tibial vein and the tibial nerve.
Since the anterior compartment of the leg is lateral to the tibia, the bulge of muscle medial to the tibia on the anterior side is actually the posterior compartment. The soleus is superficial midshaft of the tibia.
They are powerful muscles and are vital in walking, running, and dancing.
The soleus specifically plays an important role in standing; if not for its constant pull, the body would fall forward.
Levels of Myosin Heavy Chain mRNA Transcripts and Content of Protein Isoforms in the Slow Soleus Muscle of 7-month-old Rats with Altered Thyroid Status
Mar 01, 2006; Summary Skeletal muscles of small rodents contain four main fiber types, namely type 1, 2A, 2X/D and 2B fibers containing myosin...