Schaub said he heard and felt a "POP" which he thought was his ankle dislocating and relocating. This can happen with a grade II/III type of ligament tears. But, reviewing the play in slow motion over and over, I noticed something unique. It was evident that Schaub not only had his FOOT
, but also DORSIFLEXED
(pointing back up to his knee) severely. Certainly, no information has really been released. But this can be a classic presentation that fits an injury called "peroneal tendon subluxation." During the typical inversion ankle sprain, the foot rolls in. The forceful stretch on the peroneals can rip the retinaculum (part of the popping noise) that keeps the peroneal tendons positioned in the groove. [See diagrams below] As a result, the tendons can jump out of the groove (the other part of the popping noise). The tendons usually relocate by snapping back into place (completing the feeling the the ankle may have dislocated then relocated). But by then the damage is done, and the appropriate intelligent treatment is a boot/cast for 6 weeks...... most, if not all of that time non-weight-bearing. It should be noted, though, that non-surgical treatment is accompanied by ~50% recurrence rate in active athletes. This would normally result in either surgery or a retirement from the sport.
Here is a short simple diagramatic video of this type of injury for anyone interested (no blood or gore).