The numbness is a sign that something is going on neurologically. That can be anything from the nerves being constricted/pushed on, etc. as a result of improper skeletal structure/posture. If the neurologist said that everything is fine, then I would tend to say that it's a muscular imbalance (caused by poor alignment/posture) that is causing much of the problem.
I'm a certified posture alignment and pain management specialist who re-educates muscles to "do thier job". I've worked w/ quite a few neurological issues, INCLUDING quads and paraplegics and have gotten excellent results.....feeling returning, getting rid of the numbness, etc.
Might want to go online to the EGOSCUE website and check it out. You can actually e-mail a therapist, if you want, and ask ?s. If you are in the Fishers area, I'd be MORE THAN happy to take a look at her, give you referrrals, etc.
Let me know.