Besides all controversies surrounding Lance Armstrong, I thought it was interesting to look at his running stride since his return to triathlon. After a pro-cycling career, Lance Armstrong has very strong quadriceps and calves. When he began competing in marathons after his retirement from cycling, he looked like a very fit big heel striker and overstrider (hitting the ground in front of him with a straight leg (or almost), as shown on this picture taken when running the NYC marathon.
(Please notice the runner next to Lance, winner of the 1980, 1981 and 1982 NYC marathon, Alberto Salazar himself. Note also the choice of shoes of Salazar, quite far away from racing or minimalist shoes)
Lance really changed his running technique when we look at the pictures taken from one of his recent triathlons ; he has also evolved towards more lightweight and flexible running shoes.
Lance has some sort of asymmetrical movement between his left and right legs ; it tends to result in the fact that it has a slightly different way to hit the ground with one foot and the other. As shown on the picture, he tends to turn outwards his right foot, whereas his left foot remains straighter.
Here is a frame by frame shooting of his feet landing:
Here is a sequence of his stride :
We can notice the hyperextension of his back on the last picture above.
Above, we can see better the motion of his foot: I am of the opinion that his posture is still far from optimum because he is pulling his shoulders to more behind him and run with an arched back (a default fairly common among swimmers) ; maybe these pictures were taken towards the end of race and fatigue maybe explains this. This kind of posture does not help using gravity in the best manner. Moreover, Lance still has a strong tendency not to put his foot close from his center of mass but fairly ahead of it. He probably suffers from stiff hips, a flaw fairly common between bikers.
In conclusion, Lance has definitively changed his running technique to use more his glutes and hamstrings (rather than fatigued quadriceps after the cycling leg of a triathlon) and probably to limit possible trauma: Lance had suffered injuries when he started using (including a problem with his knee).
Happy Feet Running Light!