Postural Restoration Institute Practice Test

Transverse mobility works best when the body has a solid fronal (frontal plane) stability base in the lower thorax through the hips and pelvis. In PRI, rotational movement is most efficient once the frontal plane strength in that region is well established, because a stable axis allows the trunk to rotate without collapsing the pelvis or rib cage. If the frontal plane system isn’t developed there, attempting transverse mobility risks compensations and misalignment, rather than clean rotation. This is why the statement that transverse mobility can be used only when frontal plane strength is well established below T8 through the hips and pelvis is the best fit. Options that rely on ankle flexibility alone, claim independence from strength, or suggest mobility can occur without any frontal plane control don’t fit how PRI views the organize-and-mupport system necessary for rotation.