Wiktionary
legcuffs
n. (plural of legcuff English)
Wikipedia
Legcuffs
Legcuffs are physical restraints used on the ankles of a person to allow walking only with a restricted stride and to prevent running and effective physical resistance.
Frequently used alternative terms are leg cuffs, (leg/ankle) shackles, footcuffs, fetters or leg irons. The term "fetter" shares a root with the word "foot".
With respect to humans, shackles are typically used on prisoners and slaves. Leg shackles also are used for chain gangs to keep them together.
Metaphorically, a fetter may be anything that restricts or restrains in any way, hence the word "unfettered".