So I was running on a nature trail by my place last week. About 1.5 miles in on a particularly brutal downhill stretch, I roll my left foot underneath me. I catch myself and stop, thinking "Oh. Man, that'd really suck to sprain an ankle out here." Run about 50 more feet, and sure enough, roll my RIGHT ankle underneath me, only this time its accompanied with a wonderful 'pop'. I hopped around in circles for a good minute or two and was able to walk it off, and ran the remainder of my 4 miles. Still, a pop is never good, so when I got home I crashed on the couch and kept my leg elevated. Sure enough, by that night it had tightened up considerably and by the next morning I couldn't put my full weight on it.
Of course, my natural curiosity gets the best of me. I hobble over to my bookshelf. Open up Netter's Plate 527. "Ligaments and Tendons of Ankle".
Looking at the mechanism of injury, my foot was plantarflexed and inverted at the time of the pop. Physical exam reveals mild non-pitting edema of the lateral side of the ankle. Palpation produces pain between the lateral maleolus and the calcaneous. No significant loss of range of motion or pain on dorsiflexion. No significant loss of range of motion but pain on plantarflexion. Pain on eversion and inversion of the foot with limited range of motion.
Diagnosis: Likely grade II strain of the calcaneofibular or anterior talofibular ligaments. The pop is worrisome and a less likely but more serious diagnosis of grade III strain is plausible. The fact I can still dorsi and plantarflex my foot and that I was able to continue running post-injury is a good indicator of a less severe injury.
Treatment: The RICE protocol. Rest, Ice, Compression, and Elevation.
... This is what happens when a medical student has nothing to do. I think I need help.