I won’t disagree with hip extension throughout the downward portion of the leg swing and I won’t disagree that max strength work in fuller ROM squats allows one to increase angular velocity of those joints with a greater angular impulse. However I do have a couple of questions, is that greater angular impulse directly related to changing/increasing leg stiffness? If that higher angular velocity is through a greater ROM, is it enough for that velocity to offset the change in ROM? I still believe even with greater angular velocities generated the muscles in the legs have to deal with those velocities to produce the stiffness necessary to maintain speed and given that step ratse are set to preferred internal controlling (coordinated) structures, most likely to keep a stabilized motor pattern based on leg stiffness and compliance of the previous step and the ROM of the current step as well as the momentum of the COM. This is all set up in the acceleration pattern is it not? I think it is, the acceleration pattern transistions from a more concentric ssc initiated cyclic activity to a more reactive, elastic ssc-compliant activity in which ROM at each joint goes through a greater to smaller ROM while in contact with the ground as ground contact time decreases. Even though the activity itself requires greater overall ROM in each joint throughout the unsupported phases of each step. For some reason, my training progressions fell in line with moving from greater ROM work while in contact with the ground to smaller ones and from smaller ROM work in joints while not in contact with the ground to larger ROM work.
I just gravitated to it naturally trying to find out what worked. Remember I used to work long to short, but I changed to a short to long approach with some ends to middle type work as recovery/conditioning in tempo and special endurance 2 as the long end with acceleration and maxV as those the short and speed endurance/special endurance I as the middle. However most of the work early on is acceleration/maxV work as opposed to tempo/spec II.