This is one of the ground based exercises from my upcoming ankle book. Look A.T.'s, we've got to move past this inner core/outer core stuff- and all the testing and corrective exercises that go along with it. If you have no idea what I'm talking about, good for you. The model that validates it is 35 years old now, and the newest motor control research does not support it.
The core already knows what to do and when to do it and how strong to do it and in what direction to do it and in what plane to do it and at what velocity to do it; kind of like Beetlejuice from the Howard Stern show. Give the body a movement task. If it zigs when you expected it to zag it is outside the zone of function. Shorten one or more lever arms and try it again.
What's old is new. Unfortunately, what's new is old.