hello, i started sprinting as my HITT cardio for lacrosse 3 months ago and had the worst form as most people who start sprinting immediately do. however, i finally learned how to get proper stride, push from the balls of feet and use the posterior chain instead of glutes.
i have one final problem, i can't keep my back up.
my back is not flexed nor arched when i sprint, but it never points up, it points a little down.
instead of being perpendicular to the ground, it's on a 75 degree angle to the ground.
i try to consciously keep it up but it wont. sorry, i know this question may sound a little confusing.