▁functional ▁properties . ▁The ▁most ▁famous ▁example ▁of ▁an ▁iron ▁hand ▁was ▁made ▁around ▁the ▁year ▁ 1 5 3 0 , ▁being ▁the ▁second ▁prost h etic ▁hand ▁made ▁for ▁the ▁German ▁kn ight ▁G öt z ▁von ▁Ber lich ingen . ▁ ▁Most ▁iron ▁hands ▁are ▁based ▁on ▁the ▁same ▁construct ive ▁principles , ▁although ▁there ▁are ▁considerable ▁differences ▁in ▁complexity . ▁F ingers ▁can ▁be ▁flex ed ▁pass ively ▁( for ▁example ▁using ▁the ▁health y ▁hand ) ▁and ▁are ▁locked ▁in ▁place ▁by ▁a ▁r atch et ▁mechanism , ▁similar ▁to ▁those ▁of ▁contemporary ▁fl int lock s . ▁Ext ension ▁of ▁the ▁fingers ▁works ▁by ▁spring ▁pressure . ▁ ▁Bibli ography ▁▁ ▁L öff ler , ▁Lie b hard : ▁Der ▁Er s atz ▁für ▁die ▁ob ere ▁Ext rem ität : ▁die ▁Entwicklung ▁von ▁den ▁ersten ▁Ze ug n issen ▁bis ▁heute . ▁Stuttgart : ▁En ke ▁ 1 9 8 4 , ▁. ▁ ▁Put ti , ▁Vitt orio : ▁Historical ▁Pro st hes es . ▁In : ▁Journal ▁of ▁Hand ▁S urg ery . ▁Vol .   3 0 , ▁No .   3 , ▁Edinburgh : ▁ 2 0 0 5 , ▁pp .   3 1 0 – 3 2 5 . ▁ ▁References ▁▁ ▁Category : Pro st het ics ▁Category : History ▁of ▁mechanical ▁engineering <0x0A> </s> ▁The ▁Ind ividual ▁World ▁Po etry ▁S lam ▁( i W PS ) ▁is ▁a ▁year ly ▁poetry ▁sl am ▁tournament ▁put ▁on ▁by