A positive Pelvic Rock Test (iliac compression test) indicates injury to which structures?

• A. Lumbar spine
• B. Acetabular fracture
• C. Hip joint capsule
• D. Sacroiliac sprain, inflammation, or fracture

Answer: (D)

The main concept tested is sacroiliac joint integrity. The pelvic rock (iliac compression) test loads the sacroiliac joints by pressing the two ilia toward each other. If this maneuver reproduces pain in the SI region or causes focal tenderness, it points to SI joint pathology. This can include a sprain of the SI ligaments, inflammation around the joint, or a fracture in the sacroiliac region. The test specifically targets the SI joints rather than the lumbar spine, the acetabulum, or the hip joint capsule, so a positive result most strongly supports sacroiliac involvement.