I also think you and I have some philosophical differences as I see nothing wrong with landing flat footed. ..... Given that data when looking at his form I put more emphasis on the bouncing and springing off at the toes as his problem
I think we actually agree on that and maybe I'm just not expressing myself correctly - When I wrote 'flat footed' I was trying to make a distinction between the good 'midfoot' landing and slamming the foot into the ground, which it what it
looks like to me in his case. And now that you point it out, it does seem inconstent, different on each leg and even from stride to stride.
I'm also, like you, dead against using footstrike as anything other than an analytical tool, if that. It being the
result of the form and not the starting point (been saying that for many years, even in the shoe forum at rwol whenever someone posts the question 'Best shoe for developing a forefoot strike', lol... gah!).
I'm curious about the relatively recent talk of heel landing under the COG. I've tried it and I have to force it to happen, feels horrible and really doesn't make sense to me. Ok, if we're talking nanoseconds, maybe some people with touch down with the heel first but I'd suspect some kind of anomoly in their biomechanics - or really heavy dorsiflexing(?).
What about his stride length? It would be good to know how fast he's running, but it looks like a slow pace with much too-long, loping strides, which is what I would see as the main cause for the vertical bounce (and view as a remnant of running in shoes).
Also, note that I've only said he's on the verge of overstriding. I don't think we're that far apart at all but you have the experience and the better trained eye for the details so if you think he's well within the safety zone, I default to you
To me, it's easy to envision the Kyanos on his feet, do you see what I mean? And I really do think the old standard 'shorten the stride, increase turnover' could be the best jumping off point for him. I like that because it can iron out a lot of problems with no risk. Either it works or not and if not, then just leave it, no harm done. Other things like 'bend at the knees', 'pull the feet up, don't push off', 'more knee lift', 'engage the hamstrings', 'lean from the ankles' etc., are really hard to put into practice and people can mess themselves up if they don't have someone there to assist them.
Something just occurred to me: (I think) you tend to view runners from a competetive standpoint ie getting faster/more efficient, and I'm thinking much more casually ie generally slower paces and basic injury avoidance.