In two words, weak glutes. Months later, plantar fasciitis and hallics longus tendonitis.
Right after I got hurt, I had a disaster of a PT experience about which I posted here and will not rehash. When I finally started feeling better, I thought I'd try another PT. I got a great recommendation for a place that caters to runners & triathletes. They don't accept insurance, but luckily, my plan will pay a decent amt for out-of-network providers. I end up being out of pocket a bit more than double my regular copay, after the insurance provider reimburses me. It's worth the money---the PT spends an entire hour with me and only me. And the PT is very experienced, listens, and did more than just treat the injury.
I'll spare you a lot of the details, which, quite frankly, I find fascinating, but my foot issue is due some major muscles in my right leg not firing (glutes, in particular). My poor calf and foot muscles took up the slack, and when I started logging decent mileage, PF and the toe tendonitis resulted. I"m not sure how this happened because I have always included strength/weight training into my regimen. I think that I might have incorporated some Chi running techniques incorrectly and my leg stopped working (my fault, of course, nothing against Chi running). I've been working on relearning how to fire my glutes and am doing a exercises to strengthen them. To put it mildly, it has not been easy, and I have to be very mindful of using those muscles, even on the bike & in the pool. I also learned how to walk correctly.
In addition, the entire right side of my torso was in severe muscle spasm, which made my "functional scoliosis" much worse. After some very effective deep muscle massage, I am now an inch taller (much to my husband's chagrin). My spine is just about straight.
I have two more sessions to go and after that, I'll continue to visit the massage therapist there every 4-6 weeks to keep my spine in line.
Ironically, the new issue of Running Times has an article about glutes not firing & resulting injuries. If you are a runner, it might be worth reading.
I decided that I'm not going to run again. I'm happy with that decision.