Table 1.
Some orthopedic tests requiring PSIS identification
| Procedure | How performed | Interpretation |
|---|---|---|
| Seated bilateral PSIS palpation | Examiner places thumbs on PSISs, assessing for vertical displacement. | Inferior PSIS –> posterior innominate rotation; Superior PSIS–>anterior rotation2,3 |
| Prone PSIS identification as anatomical landmark | Examiner identifies PSIS in relation to sacrum. | Using a PSIS landmark may increase accuracy of numerating lumbar segments4,5 |
| Palpation of PSIS Y-axis unleveling, seated vs. standing, as indicator of anatomic LLI | Vertical PSIS displacement seated compared with standing displacement. | Any difference in vertical PSIS displacement seated compared with standing displacement suggests anatomical LLI6,7 |
| Sacroiliac motion palpation | Seated or standing, examiner observes or palpates for sacroiliac excursion during movement (sitting flexion test8, step test9, etc.) or endfeel with digital pressure. | Lack of excursion during active or passive sacroiliac movement indicates restriction; hard end-feel with digital pressure indicates fixation10,11 |
| Pain provocation | Digital pressure applied to PSISs. | Tenderness of PSIS on palpation indicates sacroiliac dysfunction12 |
| PSIS identification to allow sulcus depth determination | Thumbs probe relative depth of the sacroiliac joints. | Asymmetry indicates inter-innominate sacral base rotation13 |