In the bondage scene, we have heard people say that “once the damage is done it’s done and there’s nothing you can do about it.” This is true in the sense that there is no quick cure for nerve damage, and prevention is by far the better strategy. HOWEVER we have also heard this used to say “well, no, I didn’t quickly untie her arm when she said it was numb, because the damage was already done at that point.” This is a gross misunderstanding of the mechanisms involved.
While it’s true that once damage has occurred you can’t quickly fix it, nerve damage isn’t an “all or nothing” thing- it happens in degrees. There are several grading systems that are used to describe nerve damage – the most common, developed by Seddon, divides nerve injury into three categories according to severity: neurapraxia, axonotmesis, and neurotmesis. Another commonly used classification system developed by Sunderland divides nerve injury into five categories, first to fifth degree. Neurapraxia or first-degree injury involves only transient functional loss that spontaneously resolves, while injuries on the other end of the spectrum involve complete severance of the nerve from which there will be no recovery without surgical intervention, and maybe not even then.Even within these grading systems, injury happens on a gradient, not step-wise.27 So releasing that limb from bondage right away might be the difference between a first degree injury that resolves in a few hours vs. a third degree injury that means your bottom can't write (and can't work) for a month after your scene.