Stress Reaction

The Diagnosis
After 5 weeks, 4 doctors, 3 x rays, and 1 MRI, the results are in.  They are determining my injury a "stress reaction".  Basically, the radiologist and 2 foot specialists reviewed the MRI and couldn't find an exact fracture site, just an area in the 4th and 5th metatarsals that had some edema, inflammation, and trauma.  If I continued running on it, eventually I would have a fracture in the bone. 

The Treatment
I'm supposed to stay off my foot for a week or so, and use crutches or a walking boot. It could take 6 days to heal, it could take 6 months to heal.  I'm allowed, and encouraged, to cross train.  Then, when I don't have pain walking in my normal shoes for a week or so, I can slowly start adding in running. 

The Cause
The foot specialist says he doesn't know what caused it.  I would love to know the reason so I know how to prevent it in the future.  Since my training has been legit (NOT too much, too soon) and my diet is healthy and well-balanced, the dr speculates that when I had the pain in the ball of my foot, I may have altered my gait.  This may have put undue stress on the outside of my foot, hence my 4th and 5th metatarsals. 

The Good
It is encouraging that there isn't a broken bone.  Which means it should heal faster than a normal stress fracture (6 weeks).  I've also been running for 33.5 years without ANY type of foot pain or injury.  Hopefully this is a one-time fluke and not a regular occurrence. 

The Bad
As previously stated, the doctors and myself don't really know exactly what "this" is, and what caused it.  Therefore, it's hard to prevent it from happening again.