The word "soleus muscle" is spelled /soʊˈliːəs ˈmʌsəl/ in IPA phonetic transcription. The first syllable "so" is pronounced with a long o sound /oʊ/, followed by the long e sound /iː/ in the second syllable "lee". The stress is placed on the first syllable, hence the accent symbol /ˈ/. The "u" in "us" is pronounced with a short sound /ʌ/. Overall, the spelling accurately represents the pronunciation of this muscle found in the human leg.
The soleus muscle is a powerful muscle of the lower leg that forms part of the calf. It is one of the two major muscles, alongside the gastrocnemius, that make up the posterior compartment of the leg. The soleus muscle originates from the upper part of the fibula and tibia bones. Specifically, it arises from the soleal line of the tibia and the medial border of the head of the fibula.
The soleus muscle runs down the back of the leg before inserting by a strong tendon onto the calcaneus bone, commonly known as the heel bone. It lies deep to the gastrocnemius muscle and contributes to the formation of the prominent calf muscle. Despite being smaller in size compared to the gastrocnemius, the soleus muscle is particularly crucial for various movements of the foot and ankle, primarily involved in plantarflexion – the downward movement of the foot.
The primary function of the soleus muscle is to assist in walking, running, and standing by controlling the flexion of the foot at the ankle joint. It helps maintain posture and balance, particularly during activities such as jumping and propelling the body forward while walking or running. Additionally, the soleus muscle plays a crucial role in venous return, as its contractions help pump blood back up from the lower extremities against gravity, aiding circulation throughout the body.
The word "soleus" comes from the Latin word "solea", meaning "sole" or "sandal", because the muscle has a flat, sole-like shape. The term "soleus muscle" was first used in the early 18th century to describe this particular muscle located in the calf region.