Sprinting? Like a pole vaulter? You must be joking! If you let the point drop too far while sprinting with a sarissa you would BECOME a pole vaulter - I'm not sure that falling down on top of your enemies really helps....lol!

With very well trained phalangites, a slow jog might be feasible without losing formation - or a fast jog with the sarissas in a vertical position - but no more than that IMO.

Changing formation depth or facing rapidly, that's possible with well-drilled and disciplined troops.