as the heel plants on the ground, the rest of the body has to accept the weight onto that foot. imagine taking a step while youre walking. putting your foot out, you subconsciously feel this to be a very normal act, but thats only because you are confident the ground youre walking on is flat. take that assumption away and your body is going to be searching for and anticipating that contact (whether this is done consciously or not depends on the assumed terrain and lighting conditions amongst other factors).

I think the other area im taking issue with is the extension of the arms when they are in front of the torso (elbows being brought backwards look convincing enough). Particularly with the back arm. the extension looks over exaggerated and the wrist is bent slightly weird. imagine her wrist twisted 1/4 revolution towards the camera and i think the angle would be more proper. in addition, the forearm isnt often brought that high into the air when one is jogging at this pace. the forearm lines stay fairly parallel to the ground throughout. i think if you fix this with your back arm in particular, youll find that the animation might look entirely more comprehensive.