To row, or not to row?

Today was 'finger digging into tendon' day again. The bruise from last week hadn't completely faded, so it was a double dose of ouch.
My treat today was a bit of running on the treadmill. I had a seven minute fast walk to warm up, then alternated between two minutes of running and two minutes of walking for three sets. I am as graceful on a treadmill as an elephant on a tightrope, and I spent the entire time terrified that I was going to fall flat on my face. (I'm pleased to report that I didn't.) It felt so good to be running again, even if only for a few minutes.
It was quite unnerving having my running style analysed, but my physio has given me plenty of advice about changing my stride length, landing in a certain way and keeping my posture upright, which should make a big difference to my long-term running ability.
I also did some more balancing exercises, and ten sets of calf exercises.
"How does that feel?" my physio asked.
"Umm...it feels like the back of my leg is on fire."
"Good" said he.
Really? Not from where I was sitting!
After much consideration, we have decided that I won't run in the Birmingham half marathon. If London wasn't so important I'd probably take the risk and hope for the best, but I have to prioritise. I'm gutted because I've worked so hard to train, but I have to look on the bright side and think that I've now got a good fitness base to build on for my London training schedule.
I have permission to cycle, swim, walk and row as much as I want. (Just to clarify, that's 'row' as in use a rowing machine, not 'row' as in queue up, or 'row' as in argue. Shame. I think I'd have more endurance at the arguing, although hubby probably wouldn't be impressed.)
I'm restricted to using a treadmill twice a week, and must drop the stretching exercises to alternate days. I should be able to build up the running gradually over the next few weeks, but only on a treadmill to minimise the impact. Watch this space for news of a broken nose...I think falling off is almost inevitable.
My final bit of news today is that I have the orthotics fitted in my running shoes. How can I describe them? It's like walking with stones in my shoes, and my legs are already aching from the changes to my posture, but it should help to prevent a reoccurence of this kind of biomechanical injury.
I'm not entirely sure what biomechanics are - I gave up physics 'A' level after a year - but it sounds like I know what I'm talking about, doesn't it?