An Etymological Dictionary of the German Language/Rist
Rist, m., ‘wrist, instep; withers,’ from MidHG. rist, riste, m., f., and n., ‘wrist, instep’; OHG. *rist, as well as the implied earlier *wrist, are by chance not recorded; comp. Du. wrist (dial. Frist), AS. wyrst, wrist, E. wrist, OFris. riust, wirst, ‘wrist, ankle,’ OIc. rist, f., ‘instep’; Goth. *wrists is not recorded. The primit. meaning of the cognates is usually assumed to be ‘turning-point,’ Rist being referred to a Teut. root wrī̆þ, ‘to turn,’ which has been reserved in E. to writhe, as well as in ModHG. Reitel, ‘packing-stick’ (MidHG. reitel for an earlier *wreitel), Other etymologists connect the word with Gr. ῥίζα (from *ϝρισδα?), ‘root.’ Yet OHG. rîho (for earlier *wrîho), ModHG. Reihen, is probably most closely connected with the cognates of Rist, so that Goth. *wristi- would represent wrihsti-, and thus imply an Aryan root wrī̆k.