Cooperstein R, " Cooperstein R, "Padded Wedges for Lumbopelvic Mechanical Analysis" Journal of the American Chiropractic Association, Oct 2000: 24-6.

Padded wedges, most closely associated with practitioners of Sacro-Occipital Technique, are used to treat pelvic torsion. The wedges are placed asymmetrically under the patient, either supine or prone, to serve as fulcrums that allow gravitational forces to affect the position or movement of the sacroiliac and lumbar joints. Blocking may as wll be considered an orthopedic test, since the purpose of virtually any such test is to put the joints under investigation in stressed or potentially de-stressed positions, noting the symptomatologyical changes and drawing the appropriate conclusions. Padded wedges, apart from their value in treating patients, can thus be used to generate diagnositic information, as well, that amounts to mechanically assisted orthopedic testing.