I haven't tried it yet, but I believe you should be able to use the console to permanently cripple yourself with player.forceav. The various body parts should, if they haven't changed since 3/NV, be PerceptionCondition (your head), EnduranceCondition (torso), LeftAttackCondition (left arm), RightAttackCondition (right arm), LeftMobilityCondition (left leg), and RightMobilityCondition (right leg). If you use player.forceav LeftMobilityCondition 0, for instance, that will set your left leg condition to 0. Not sure whether or not it will actually prevent Stimpaks from healing that.