I’m curious what the reasoning is around maximizing hemi-90-90 position for pelvis patients. I’m certainly doing my best to engage in more hemi 90-90 positions for my pelvis patients but would love to wrap my head around the ways it particularly helps focus on the right pelvic mechanics.
The hemi 90-90 position maximizes the frontal plane of the pelvis in the inlet and outlet.
For example, in the Right Sidelying Supported Hemi 90-90 with FA IR, when the left knee is pressing into the towel roll you’re getting left femoral adduction which places the left obturator internus/iliococcygeus in a position to allow the left pelvic outlet to abduct. Then as the you get the left femur to IR, the left posterior inlet goes into IS ER allowing the anterior left pelvic INLET TO ADDUCT via the left iliacus. So, the left femur adducts, left outlet abducts, and left inlet ADDUCTS = desired frontal plane activity of the pelvis on the left.
And now let’s discuss an example of right pelvis frontal plane desired activity, with the Left Sidelying Supported Right Glute Max with Hip Extension and FA Abduction technique. The right femur abducts therefore the right outlet adducts (via inferior fibers of the right glute max) and the right inlet ABDUCTS (via superior fibers of the right glute max).   – Lori Thomsen, MPT, PRC
