Is stretching safe with a calcaneal stress fracture?

A runner with a calcaneal stress fracture has a problem. So we got on a call. 

The problem with calcaneal stress fractures is not healing. The heel bone "heals" fast!

Runners with calcaneal stress fractures really have 2 problems:

1. How do I let the heel bone heal fast

2. How can I fix the scarring that happens during step 1?

I was recently doing a call with a real runner who had a calcaneal stress fracture. She was having some issues because she was returning to running.  The problem was not the heel bone.
 
She noticed a lot of stiffness and irritation around the ankle joint, because she'd been immobilized and off of the foot for quite a long time. Anytime you use a boot or crutches, you get lots of indiscriminate scarring. You can't run unless you fix that.
 
Is stretching safe with a calcaneal stress fracture? 
 
Well, that's what we're talking about today on the Doc On The Run Podcast.