So in the video posted here, notice the general improvement that occurs after applying Myoskeletal Muscle Spindle techniques.
First test, this runner has limited range of motion, second test better, and third all the way!
I feel that the limited ROM is initiated by a tight line, psoas and rectus femoris, potentially hip capsule adhesions as well. So we stretch it to defeat Davis's Law. Then a quick few minutes of manual muscle spindle stim work.....Enjoy!