You ever watch someone run right at you and notice the running mechanics might be slightly out of sorts. Maybe the athlete runs bowlegged or the feet angle out or in.
Sometimes, this can be structural and there is nothing you can do about it. Meaning, the legs were developed this way and you can’t rebreak those bones to align them just right.
Other times, these mechanical issues happen due to strength imbalances. In this case, it very well could be that your ankles are weak and can’t support the generated force needed to run at the high speeds.
If the ankles are weak, they can control where your shin points to direct the force you are trying to generate. If the shin ends up pointing straight up due to the heel collapsing because of the weak ankles, then the force is going up rather than forward down the track.
The way to get the ankles stronger is through isometric exercises. Ultimately, the goal is to direct the force through the big toe.
Sometimes you will see the foot land on the outer part of the foot and through the four other toes. If that happens, the force tends to go laterally and you have to counter that by swinging the opposite arm to keep you going straight ahead.
If you can strengthen the big toe and train the body to have the forces go through the big toe, then the forces can go straight ahead and there is nothing to counter. Your arms can just swing naturally to help drive the speed.
The question is how do you strengthen the big toe to get the ankles stronger?
The first exercise is to do what most people call a calf raise and focus on pressing down through the base of the big toe. You also want to raise the heel up high enough to place a tennis ball underneath.
If you can hold that position for 30 seconds that is sufficient. 2 minutes would be the ultimate goal. You hold it for 2 minutes, your ankle can handle the forces generated while running at high speeds.
If you can hold it for 2 minutes, then you can start adding some weight. Either having someone push down on your shoulders or holding a dumbbell.
When that becomes doable, you might want to stand on the edge of a plate or step with just the big toe. That is somewhat of a challenge.
Do that several times a day early on for 7 days and then transition to doing it before your practices and/or games. This will reinforce the pattern to run through the big toe and allow you to develop your maximal speed.