▁a ▁bu il dup ▁of ▁lip of us cin ▁and ▁cross - link ed ▁prote ins ▁causing ▁an ▁accum ulation ▁of ▁non - cont ract ile ▁material ▁in ▁the ▁ske let al ▁mus cle ▁and ▁contribute ▁to ▁s arc open ic ▁mus cle . ▁ ▁Di agn osis ▁Multiple ▁di agnostic ▁criteria ▁have ▁been ▁proposed ▁by ▁various ▁expert ▁groups ▁and ▁continues ▁to ▁be ▁an ▁area ▁of ▁research ▁and ▁debate . ▁Despite ▁the ▁lack ▁of ▁a ▁widely ▁accepted ▁definition , ▁s arc open ia ▁was ▁assigned ▁an ▁I CD - 1 0 ▁code ▁( M 6 2 . 8 4 ) ▁in ▁ 2 0 1 6 , ▁recogn izing ▁it ▁as ▁a ▁disease ▁state . ▁ ▁S arc open ia ▁can ▁be ▁diagn osed ▁when ▁a ▁patient ▁has ▁mus cle ▁mass ▁that ▁is ▁at ▁least ▁two ▁standard ▁devi ations ▁below ▁the ▁relevant ▁population ▁mean ▁and ▁has ▁a ▁slow ▁walking ▁speed . ▁The ▁European ▁Working ▁Group ▁on ▁S arc open ia ▁in ▁Old er ▁People ▁( E W GS OP ) ▁developed ▁a ▁broad ▁clin ical ▁definition ▁for ▁s arc open ia , ▁designated ▁as ▁the ▁presence ▁of ▁low ▁mus cle ▁mass ▁and ▁either ▁low ▁mus cular ▁strength ▁or ▁low ▁physical ▁performance . ▁Other ▁international ▁groups ▁have ▁proposed ▁criteria ▁that ▁include ▁metrics ▁on ▁walking ▁speed , ▁distance ▁walked ▁in ▁ 6   min utes , ▁or ▁g rip ▁strength . ▁Hand ▁g rip ▁strength ▁alone ▁has ▁also ▁been ▁advoc ated ▁as ▁a ▁clin ical ▁marker ▁of ▁s arc open ia ▁that ▁is ▁simple ▁and