I prefer running on the ground and using force plates for research analysis for many reasons.
I’m not aware of the research you’ve performed using force plates. Could you pass your studies along for us to read?
When accelerating the horizontal forces are drastically different than when at max speed because of posture and foot strike. Some proponents of the horizontal debate cling to studies showing a higher correlation of horizontal forces with performance, but after looking at the studies, the same problem that we see with regular sleds being used at top speed, or past 40 meters. Jon Goodwin’s presentation was very elegant with his visuals showing what happens at acceleration and at max speed. My added photo of the Tredsled is a polite reminder to examine the research before we start drawing the wrong conclusions.
The fact that horizontal force diminishes as speed increases, posture becomes more erect, and GCT limitations become paramount, does not directly answer the question, “What is the factor limiting Max V?” The fact that horizontal forces show a higher correlation with performance as well as the fact that sprinters are capable of producing more vertical force at Max V than they demonstate in a sprint, should be clues that the empircal data is trying to tell you something and should not be ignored in favor of theoretical musings, regardless of how pretty the slides are.