DEAR DOCTORS: I get a cramp in my left calf when I run for more than 20 minutes. When I slow down, it goes away. I told my doctor about it and she wants to do something called an ankle brachial index.

The peroneus longus muscle (or fibularis longus) is a major mover and stabilizer of your foot and ankle. The muscle runs down the lateral side of your lower leg and attaches to your foot.

4 NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, The University of Queensland, Brisbane, Queensland, Australia Correspondence to Professor Bill Vicenzino, School of ...