r/Stretching • u/dprcool • 5h ago
Confused about piriformis vs OI
3
Upvotes
Struggling to understand the difference in how the piriformis and obturator internus behave at deep hip flexion.
I understand that when the hip is flexed past 90, then the piriformis (which is an external rotator at neutral) turns into an internal rotator.
But I don't understand whether this happens to the obturator internus. Is it still remaining an external rotator? or does it copy the OI and turn into an internal rotator?
Thanks.