I experience a pretty intense tightness/pain doing the lying butterfly/groin stretch, in my right hip joint area. It almost feels like the joint is locking up. Doing this stretch when sitting is not so bad.
However my left leg is quite flexible, I can even sleep with my left leg in this position.
It feels like pain in the joint itself, not muscle pain. If I try this stretch for a period of time, even if I do it very gently, the pain persists for a few days afterwards.
Also my side split flexibility is very poor, because of a similar joint lock sensation. My side split is most difficult when lying on my back with my legs up against a wall. Standing upright side split is not so bad. My front split flexibility is pretty good. My hamstrings are short.
Does anyone with knowledge of hip joint anatomy have any idea what might be happening?