The posterior crural intermuscular septum. Macroscopic structure and relation to the fibular muscles
Reimann, R.
Acta Anatomica 102(4): 411-426
1978
ISSN/ISBN: 0001-5180 PMID: 696229 Document Number: 130464
In 100 cadavers the macroscopic structure of the posterior crural intermuscular septum and its relation to the muscles arising there were examined. The areas of origin of these muscles show standard sizes well marked off. The dilatation and the localization of those standard sizes were evaluated and the distal limiting marks of the areas of origin were depicted showing the relative dimensions in regard to fibula length. At the front of the septum the area of the peroneus longus muscle extends down to the 7/10 part of the fibula. Further down the peroneus brevis arises from the septum between the 7/10 and 9/10. At the back of the septum the soleus muscle arises between the distal edge of the gap for the common peroneal nerve and the 2/4 of the fibula. Further down the area of the flexor hallucis longus muscle extends down to the 9/10 of the fibula. There are only few exceptions to these standard data. The distal limiting mark of the area of the soleus muscle shows a large range of variation (1/4 of the length of the fibula), indicating the progressive tendency of evolution of this muscle. The chimpanzee type of the human soleus arises in an area reaching far downwards at the fibula and the septum, the gorilla type shows a small area of origin there. Contradictory descriptions in textbooks discussing the origins of muscles arising from the posterior crural intermuscular septum were checked. Areas of the septum without origins and gaps for nerves and vessels are described.