Peroneal tendonitis was one of those conditions I never used to like seeing as my success rate in treating it was typically pretty poor. Most cases seemed to have a “overpronated” foot, so what did one used to do with feet like that: foot orthotics to fix the “overpronation”! And then wonder why they were typically not responding.
Then we started doing our research on supination resistance and it was one of those real light bulb moments. The solution became so freakin obvious, I kicked myself for not picking up on it sooner. For peroneal tendonitis, you need to pronate the foot some more (even if its already “overpronated”!) with lateral wedging. I wrote about our research and thought processes here: Peroneal Tendonitis in Runners. The first couple of cases of Peroneal Tendonitis I had clinically even before the research was completed were almost instant cures. Nothing like an anecdote or two to confirm preconceived biases!
The use of lateral wedging for peroneal tendonitis has become pretty common now. The rationale and biomechanics of it make sense and the clinical experience is certainly supporting it.