In the first image, Alan appeared to be hunched over at a forty-five degree angle. In the second image, he then stretched backwards about twenty degrees, give or take. Simply find the width of his body from the torso up and then find the arch length of his movements using sixty-five degrees.
As a rough calculation:
83.3 * 65 / 180 * pi =
0.945 m, and 0.945 m / 2 nanoseconds =
472,500,000 m/s (
FTL).