《宋史·列传·卷一百二十四》
当初，兀有一支精锐部队，都身穿重甲，以皮绳连贯在一起，三人一组，号称 拐子马 ，宋军不能抵挡。
初，兀术有劲军，皆重铠，贯以韦索，三人为联，号 拐子马 ，官军不能当。
In the beginning, Wushu had an elite force, all wearing heavy armor and connected by leather ropes in groups of three, known as "拐子马" (literally "crutch horse"). The Song army could not resist them.