foot strike and COM

hi guys, i’ve read and noticed that faster sprinters tend to have their foot strike be closer to their center of mass. i know that increased hip height helps allow the foot to sweep under the body and land closer to underneath the COM, but what I am wondering is if my fot strike is further in front of my COM than i would like, is this likely just an elasticity or strength issue resulting in inferior hip height and it’ll come with training, or is their any mechanical or technique changes or concentrations that could help too?

Posture matters. After acceleration forward lean needs to be compensated by having your feet land in front of your body or you would fall flat on your face. At top speed your should run fairly erect.

I’ve always wondered which comes first? Does a drop in hips lead to premature foot strike or is it that when trying to reach the result is a drop in hip height?

Good posture, a neutral to posterior rotated pelvis, and stepping straight down.

That is a really good question…I hope some of the senior members chime in on this.

ironically, if i actually try to run upright i tend to end up leaning back too much. i actually was wondering after i saw video of me doing a run, but it was a submax sprint. would the faster the sprint the further ahead of the COM foot strike would have to be to prevent falling over? (as gravity is constant, but less force would be being put into the ground so more of it would have to be upward)

though i know its correct technique, wouldnt a posterior rotated pelvis make it harder to step under the COM as one’s leg while neutral compared to the hips would now be in front of the COM. and isnt stepping straight down more of a cue than reality? any slo mo videos ive seen of good sprinters actually looks like the flight phase is at about 45* and the leg actually becomes straight then sweeps back like a pendulum as opposed to merely stepping down

are there any other major technique errors on the top of your mind that can lead to lowered hip height besides reaching? and i’m thinking it’s one of those reciprocal things where both are true, sometimes both at once

Suggest it is because they are trying to maintain and not continue acceleration. Similar to running down a hill

I tend to find my guys drop there hips when tired and there contact times are greater. I guess it is hard for the hips to rotate if they aren’t in the optimal height position.

i agree, though obviously in the acceleration stage it is easier to no have braking forces with that “push” mentality. i’m curious about the upright running foot strike because i think it can be a limiting factor on both the maximum speed to be maintained and the maintenance of the speed itself

this makes sense, when im fatigued i always feel that the “bounce” in my step is gone. the run i specifically noticed it in me was near the end of a tiring workout

It would actually be easier to get the foot under the hips as you would have more time to get your feet under you due to the less time spent on the backside. I will be posting a video soon about frontside mechanics as soon as the weather permits. If you are leaning back when you think of running upright this is actually a symptom of being weak in the core/postural muscles.

haha, ironically i squat 2.5x my wegiht to parallel and can human flag, i doubt core strength is my issue if anything. just took video today. i noticed that i dont seem to ever actively swing my leg backwards. my mechanics look great then my leg straightens out right before its suppose to swing back, then it just stays there til foot strike. this is making me have very loud steps, a short stride and run slow. i think this problem doesnt occur as much while racing others because id naturally pull a bit more. its as if im not stepping through the ground. i just step down until right before contact then apply like no force to the actual ground…

Heels off the ground and dorsiflexion for speed maintanance.

Back in the 80’s when I was teaching myself to coach I used to compare the sprinting action to something mechanical. Pushbikes used for racing bikes had thinner tyres then ordinary bikes, the reason I was given was to reduce ground drag. In a straight line a car with skinny tyres will go faster then one with fat tyres, the fat tyres are only needed for traction during hard acceleration.

makes sense. i remember cf used the pushing a bicycle wheel around idea for accel

I am no cf. it was silly comments like that that led to my demise as a coach.

Notice you havent made comments on frontside mechanics,

i believe my frontside mechanics are actually pretty okay so i havent said too much on them. because they mostly result from a stretch reflex, i feel like your foot strike and backside mechanics if proper result in good front side mechanics

Well if I had to come up with something I’d probably lean towards identifying a weaker core or a rounded lower back. To put it another way, attempting to achieve knee lift without sufficient strength and flexibility to maintain neutral hip position.

This is a Gatorade commercial. The last few seconds shows a sprinter with a mean forward lean. I put it in slow mo and noticed he was still able to land on com with the lean. I’ve notice a lot of jam sprinters have this style of running. Thoughts