First of all, keep in mind that I am unable to diagnose you because I am unable to examine you, this forum is for educational purposes.
The symptoms that you relate are non-specific and there are many causes of low back pain/ sciatica. The most important thing is to find out why you are having the pain, and then symptomatic treatment can be addressed. It is reassuring that your MRI (by the report that you related) does not show any serious pathology, that requires surgery, etc. Given the radiation of pain down your leg, I would suggest an EMG to evaluate for any electrical evidence of a radiculopathy (pinched nerve). I would also recommend physical therapy and medications for neuropathic pain (neurontin, lyrica, elavil, etc.). I would not suggest devices with little if any scientific support (IFT-interferential therapy or SWD-short wave diathermy) in randomized palcebo control trials (the standard for FDA approval, etc).
I hope this has been helpful.
Good Luck!
JCmcc.
I read over the information again after reading your post and looked more intently. The rounded posture that you point out, seems probable. I too have learned that posture has a certain role in many problems. I concur on your statements, if in fact, all of the facts are in and correct.
If, however, he commits to following such routines-it would not be out of league for him to seek out massage therapy and general orthoganal support from a chiro who specializes that technique. As a neuropsychologist-I tend to rec this for many people with stress disorders that cause numbness, parethesias, to name a few. If he is a desk worker-depending upon his profession-there may be stress factors (or his personal life, who knows) that contribute to this problem. I am a big believer in combinatory effects.
On another note; ex-dentist? Are you retired? Share if you want, if not, understandable.
Thanks,
John.