I assume in the human body you want muscles to have a certain strength ratio to. each other, as well as a flexibility level enough to balance.
as an example, supposedly hamstrings should be 60-80% as strong as quadriceps. if hamstrings are too weak it can increase the risk of injury.
if the chest muscles or front neck muscles are too tight, short and strong compared to muscles in the back and back of the head it can cause other issues.
is there a book on proper muscle ratios with at home strength tests to try? and what kind of medical professional would deal with these issues? I don’t think orthopedists deal with it, maybe a physical therapist.