I'm a 28yo female, very physically active (circus arts, martial arts, cycling, yoga), and have been for my entire life. I have partial hyperflexibility (arms, lower back, toes), and have been working towards general mobility and flexibility for my entire life. For the past year I have noticed chronic tightness in my calves, posterior knees, hamstrings and periformis, one leg worse than the other. My splits have worsened, it's as if my body wouldn't let me go further, only getting worse, it feels very sudden. I understand that it comes with age and all, and maybe I have overworked it.
Basically, it's normal for me to have a mild stretching or yoga practice, and within literally minutes my legs go back to being as tight as if I've just woken up. I can see no progress at all. I could never do full on forward folds, but I can easily lie down onto my left leg, while my right leg wouldn't let me anywhere near it.
It worries me because stretching - static or dynamic doesn't seem to help at all, maybe even hinders it. Sports massages leave me sore, as they should, and do nothing either. I keep well hydrated, take magnesium, my protein intake seems to be adequate. The physiotherapists I have seen don't seem to be understanding the problem. I get some relief with being taped, but not close to the ideal state. How do I untense myself?
TL DR: chronically tight muscles in the back of the legs despite stretching