distribution of sciatic nerve in hamstring muscles

regarding the importance of sciatic nerve distribution in replacement of anal sphincter and sciatic nerve block we decided to study this matter for the first time in iran. in this way 100 cadavers (88% male and 12% female) were dissected and studied by loop microscope. the results shows that primarily, according to the first branch derived from sciatic; there would be 4 main groups. if this samples were rgarded according to the second branch of the nerve, then there would be 6 accessory groups added. so, in group a the first branch was related to proximal part of semimembranosus, in group b the branch was recorded as normal variations based on the above mentioned patterns.