Don't rule out severs disease. Generally it does present as posterior but if you look at an x ray
The apophysis is plantat posterior. I see no reason why the more plantar part of the apophysis might be inflamed, particularly if the patient has a heavy heel strike on the more lateral side of the heel.
I would certainly be thinking in terms of heel cushions / raises. Otherwise (and its always tricky without the patient in front of you!), I would be thinking in terms of medial rearfoot wedging with a substantial lateral arch and forefoot valgus extension to sulcus. Strengthening exercises for the calves and stretches for the Calves and Hams. Depending on the degree of the met adductus I may also consider reverse last footwear. My objective would be to work on a less lateral and softer heel strike to reduce trauma to the lateral part of the calcaneal apophysis.
Specialist in Biomechanical Therapies
small, yellow, leech-like, and probably the oddest thing in the universe
Semper in excretum sum sed alta variat