Great question! As you rightly say, stretching the Peroneal muscles (AKA Fibularis muscles) of the lower leg isn’t easy. In contrast to how easily I achieve a stretch in my hamstrings, for example, it’s actually rather difficult to take the ankle through sufficient range to put the Peroneal muscles in enough of an end-of-range position to feel an isolated stretch.
Leigh Boyle has put together this great video highlighting some of the self-treatment options you have for getting stuck-in to your Peroneal muscles. In the video she particularly focuses on Peroneus Longus.
Soft Tissue Techniques & Stretches – Peroneals
N.B. Watch right to the end for a great couple of stretches! If you don’t have a stretching strap, try using a towel…
Hope this helps 🙂