It is basically a constructive way to negate something. You can use the adverbs 안 or 못 to negate something. In order for the above sentence to make sense, you can see the use of the negative form as a means of asking for confirmation. You could translate it to: it doesn't hurt, right? Which an English speaker would typically phrase as: are you okay? or does it hurt? The construction is often used as such. Any native speakers may of course correct me or add to my explanation!