The M.U.T.A.N.T.

[HeatDeath]

Have your kid try binding your ankles with 4-5 turns of dental floss. [Most families will contain at least one child who will enthusiastically undertake this project, I suspect.]

Breaking it'll be harder than you expect, and will require explosive motion available to mammalian leg muscles but not to the actuators the Empire used in those leg mechanisms.