Personally Yonita, I wouldn’t get too hung up on this anatomical stuff. There are two basic things that happen with anatomy within the yoga field. The first is that we as teachers and students, don’t know or learn anything at all about the bodies in which our soul dwells. We could not tell the humerus from the femur, the biceps from the quadriceps.
The second things that happens is at the other end of the continuum; we become overly occupied with anatomy and anatomical references such that it becomes a distraction from the practice.
I don’t believe what you are outlining is a “classic symptom of overloading” in Adho Mukha Vrksasana. Further, I would be curious what overloading is? Are you carrying additional weight when you are inverted in the pose? A weight vest, ankle weights, etcetera? Are you remaining in the pose beyond your capacity? Are you losing the intention of or the integrity in the pose?
Generally these sorts of things are best ferreted out through self-exploration rather than The Anatomy of Hatha Yoga. Howeverrrrr, it’s fun and often helpful (for me in my practice) when I can use the latter to facilitate the former.