Muscle of the Week: Peroneus Longus pain masking as plantarfasciitis
The peroneus muscles are on the outside of the lower leg and ankle and usually get strained when the ankle gets sprained. This makes sense to most people because the tendons run so close to the outside of the ankle.
But…..the peroneus longus tendon crosses UNDER the foot after running along side the ankle bone to help support the arch. It attaches in the middle of the arch on the bottom side.
Here is a picture of the bottom of the foot:
When the peroneus longus tendon insertion starts to pull and get irritated, it can feel like plantarfasciitis and be confusing. However, the fix is usually the same, stretch your Achilles and plantarfascia and strengthen the side to side muscles as well as get manual therapy. Sometimes orthotics help too. Your physical therapist is particularly well trained to fix this condition.