If we are talking about the ‘limb leads’ that are attached to the body, they can go pretty much anywhere. If it’s the end attached to the machine that may be slightly different, as I’ve never had experience with this (if indeed they do plug in to the machine or are permanently fixed?). The leads themselves (the sticky bits/dots) can be attached to arms/legs/torso or whatever and still have the same effect.If the leads are in the wrong order then it gives very strange readings.
This causes nurses or hcas to call for investigations.