Accessory soleus muscle
The accessory soleus muscle is an anatomical variant characterised by an additional distinct muscle encountered along a normal soleus muscle. It is uncommon with a prevalence of ~3% (range 0.7-5.5%).
The accessory soleus muscle arises from the deep surface of the soleus or from the fibula and descends anteriorly to the calcaneal tendon. Its insertion may occur into the calcaneal tendon, the upper surface of the calcaneus, or in the medial aspect of the calcaneus.
The Kager fat pad is obliterated by a well-defined area of increased soft-tissue attenuation.
Associated exertional pain can occur, especially in athletes 1.
- 1. Sookur PA, Naraghi AM, Bleakney RR et-al. Accessory muscles: anatomy, symptoms, and radiologic evaluation. Radiographics. 2008;28 (2): 481-99. Radiographics (full text) - doi:10.1148/rg.282075064 - Pubmed citation
- 2. Christodoulou A, Terzidis I, Natsis K et-al. Soleus accessorius, an anomalous muscle in a young athlete: case report and analysis of the literature. Br J Sports Med. 2004;38 (6): e38. doi:10.1136/bjsm.2004.012021 - Free text at pubmed - Pubmed citation