“加脚镣”可以翻译为 “put shackles on (someone's legs)” 或 “fasten leg irons on (someone)” 。
“put shackles on” 较为通用，“shackles”指脚镣、手铐等束缚器具，这里特指脚镣时，可明确“on someone's legs” 。
“fasten leg irons on” 中 “leg irons” 就是专门指脚镣，表达更直接、精准。
例如：The prisoner was put shackles on his legs.（那个囚犯被戴上了脚镣。 ）