Hey Jonatan, if you’d like some motion reference to accompany the still images you’ve collected, this series has some incredible imagery of starts, acceleration, and top speed mechanics. It’s in Japanese but I don’t think that will be a problem.
https://www.youtube.com/watch?v=gkPlF6L8FOE&feature=channel_page
If you’d like a higher resolution reference, I have some high speed imagery of starts/hurdles/sprints (though the quality is not quite on par with Asafa:) I could put it up for you. Just let me know if you still need materials.