拔腿 (bá tuǐ) is a separable verb (离合词) meaning to take a step, most often when starting to run or move quickly. It also extends figuratively to mean 'get away' or 'free oneself' from a difficult situation (e.g. 拔腿就跑 'take off running'). Because it is a verb-object compound, the verb 拔 and the object 腿 can split — you can insert particles like 了, 着, 过 or a measure word between them (e.g. 拔了腿). When specifying what you are fleeing from, use 从…中拔腿出来.