This is Ashlee, a collegiate sprinter who has had significant calf pain to the point where surgery for compartment syndrome had entered the conversation. Here is a brief video of her running, obviously not at top speed.
It’s a little difficult to see in the video, but my first impression was how awkward the push-off phase of her form looked. The most obvious thing in the video is how much she has to shift her hips laterally away from the pushing off foot. Upon closer examination, her biggest deficits were lack of full ankle inversion and dorsiflexion, as well as hip extension and internal rotation. These ranges are needed most at the point of push-off, regardless of the speed or stride length. Typically sprinters will run more gracefully on their toes and at faster speeds, but Ashlee looked just the opposite. The push-off phase is even more critical when sprinting or toe-running. If a runner looks worse on their toes, it’s a good bet that there is foot weakness or mobility restrictions affecting their ability to push off properly.