Resolving discrepancies in image research: the importance of direct observation in the illustration of the human soleus muscle.

A historical analysis of fourteen published illustrations of the soleus muscle from the sixteenth to the twentieth century reveals obvious inconsistencies in the representational accuracy of the architecture of the muscle. To ensure the most accurate illustrations possible, biomedical communicators should conduct direct laboratory observations. A review of reference images alone is insufficient for assuring anatomical accuracy. Having followed this protocol, three architecturally distinct regions of soleus were observed and illustrated and the final results suggest that soleus is a complex multipennate muscle with significant architectural characteristics not typically represented in published illustrations.