I think the total accumulated time from games and practice adds up over the years. I don’t think wearing pads has much if any affect but all those reps in peewee/junior high/high scool/camps/neighborhood games constantly staying low for cutting and taking hits really adds up. Tough to get tall after all that time being low.
On a related note I was watching womens college volleyball a few months ago and noticed for taller than average girls quite a few had serious anterior pelvic tilt. My guess is all that time spent in the “athletic ready” position i.e. quarter squat over the years has had an effect on them. I’m even starting to see this in high school with the constant year round club play, I figured some girls are getting 200+ days a year in, lots of them are chronically injured too.
My guys foam roll some. trying to get them to do yoga class at the gym. One of my guys just was made Parade All American. Guess what he does, yoga. No I am just thinking I need to get the tissue where I want it, then easy to maintain.
With a deep look into this issue, it is many things no doubt. Sometimes poor arm technique may keep athletes from getting lift. Sometimes it might be tissue quality, which will include mobility. Sometimes it’s a position in which they have never been in before, and as a result, I work on it at a slower speed first. The position being proper step over mechanics etc. Sometimes it might be an elasticity issue or strength issue, or just being over trained. All of the reasons above I have seen in all my athletes. With all of these issues, it was very individual.
I did Yoga while competing (track). At 1st I wasnt sure about it because the instructor is a friend of mine (about 5’4 110lbs with weights in her boots) but after a few weeks my flexibility got better and overall I felt better. Just didnt do the whole meditation humming thing
I spent some time with Boo Schexnayder and he said the athlete should feel a big split between the knees during accel and still a big split during top speed but obviously faster. He did mention it all coming from the hips. I personally have to make sure I don’t “pose or stall” in the high leg position when focusing on this cue. It seems to work better for me if I just concentrate on stepping down hard or pumping the arms hard from a tall, upright posture.
For me hip height is not a focus in the first 60m to 70m in a 100m race. As most footballers do not run much more than 30m to 40m in a hit up or in preparation for a tackle I do not believe there is any advantage trying to get the players to achieve such.
My background with sprint training of footballers is with Rugby league and Rugby union, the majority of what i did was for acceleration up to 40m with the focus on making and taking a hit. It is my understanding that an athlete who practices high hip height will not have a good step required to avoid an opposing athlete whether in attack or defence.
It is my understanding that a former successful sprinter from Australia could not accelerate fast enough to be accepted in the US college system as a football player (10.08). This could well have been because of his hip height being at the right height too early.