fa Morphometry Morphometry Original Original During the dissection of a fifty-years old male cadaver with normally fined, we observed a rare variation in the dorsum of its hands in both sides. This variation was abnormal extensor digitorum brevis manus muscle (EDBM), which originated from the dorsum of wrist and inserted to the u]nar side of the index tendon of extensor digitorum muscle. In this case, extensor indicis muscle was absent. In the present study, we argue about the historical origine, clinical importance and muscular nomenclature. Variation, Extensor digitorum brevis manus 53 65 http://anatomyjournal.ir/browse.php?a_code=A-10-304-46&slc_lang=fa&sid=1 Homa Rasouli 10031947532846006746 10031947532846006746 Yes Iran Medical Sciences University, Tehran, Iran. Ali Reza Gholami 10031947532846006747 10031947532846006747 No Mohammad Taghi Joghataei 10031947532846006748 10031947532846006748 No Mansoureh Soleimani 10031947532846006749 10031947532846006749 No Mahdi Mahdi Zadeh 10031947532846006750 10031947532846006750 No