Miami ran a variation on this play several times Sunday with some pretty consistent success. Its a "sweep play" where the running back goes to the outside shoulder of the offensive tackle, and has some room to run.
In college, this is a highly effective tactic because the fast running back can get to the edge faster than the defense. However, most NFL defenses are so quick that the effect is negated...unless you run some motion. In this case, Martin is running across the formation to the left, which would make the defense read run left. At the snap, the line starts blocking right, but from odd angles, so that they have leverage and can switch to blocking left, thus keeping the defense off balance. Meanwhile Martin comes around and takes out the linebacker "from behind" and the fullback goes and takes out the defensive back on the end.
Now, all the has to happen is that Ricky runs through the gap, and its a first down.