What is the reference point for a pelvic subluxation?

What is the reference point for a pelvic subluxation?

• A. PSIS (tuber sacrale)
• B. ASIS (anterior superior iliac spine)
• C. Iliac crest
• D. Ischial tuberosity

Answer: (A)

When assessing a pelvic subluxation, you need a stable landmark to judge how the pelvis is oriented relative to the sacrum. The posterior superior iliac spine (PSIS) serves this role because it’s a palpable, relatively fixed point on the back of the ilium near the sacroiliac joint. By comparing the heights and positions of the two PSIS landmarks, you can detect pelvic tilt or rotation. If one PSIS sits higher, it indicates a tilt toward that side or a corresponding rotation, depending on the plane of movement. The PSIS is preferred because it remains a reliable reference despite changes in position, unlike landmarks that move with hip position or soft tissue, such as the anterior superior iliac spine, the iliac crest, or the ischial tuberosity.

When assessing a pelvic subluxation, you need a stable landmark to judge how the pelvis is oriented relative to the sacrum. The posterior superior iliac spine (PSIS) serves this role because it’s a palpable, relatively fixed point on the back of the ilium near the sacroiliac joint. By comparing the heights and positions of the two PSIS landmarks, you can detect pelvic tilt or rotation. If one PSIS sits higher, it indicates a tilt toward that side or a corresponding rotation, depending on the plane of movement. The PSIS is preferred because it remains a reliable reference despite changes in position, unlike landmarks that move with hip position or soft tissue, such as the anterior superior iliac spine, the iliac crest, or the ischial tuberosity.