An Etymological Dictionary of the German Language/Annotated/Rücken

by Friedrich Kluge

Rücken, im., ‘back, rear, ridge,’ from the equivalent Middle High German rücke, Old High German rucki, earlier hrukki, masculine (Gothic *hrugja- is to be assumed); compare the equivalent Old Saxon hruggi, Dutch rug, Anglo-Saxon hrycg, English ridge, Old Icelandic hryggr. Greek ῥάχις, ‘back,’ is not allied, because krakjó- is the Old Aryan form for Rücken. It is more probably related to Old Irish crocen, ‘skin, back,’ and the Sanscrit root kruñc, ‘to bend,’ so Rücken may have been named from its flexibility. See zurück.—