In order to understand and prevent the particular rate of the common fibular nerve palsy during the traumatisms of the main stem of the sciatic nerve; the authors have studied through dissection the osteomuscular and aponeurotic relationships of 38 common fibular nerves. They blame it on the relations between the nerve and the proximal ends of the fibula; the nerve can be stretched on and mainly on its fixation on the crural fascia by fibrous tracts seen in 78.94 of the cases.