In the 17th Century, jiá gùn (Pinyin; Wade–Giles romanization, kia quen; literally, "pinch ankles") 夾棍 was reportedly a technique used in China for the interrogation of male suspects without putting their lives in danger.
The technique consisted of positioning three wooden or bamboo boards, connected by rope, around and between the suspect's bare feet. The construction of the device enabled the boards to be either snapped open and closed (like the wings of a butterfly) or gradually tightened. Each time the prisoner refused to testify or confess, the rope was pulled smartly and the boards either whacked sharply at the ankles or slowly squeezed the feet ever more tightly. A similar device called the Tean zu, applied exclusively to women, employed essentially identical mechanics to squeeze and crush the finger-bones.
The torture was typically conducted while the prisoner was forced to painfully kneel on top of folded chains made of sharpened iron links.