Study Design: A roentgen stereophotogrammetric analysis study of patients with sacroiliac joint dysfunction.

Objectives: To investigate whether manipulation can influence the position between the ilium and the sacrum, and whether positional tests for the sacroiliac joint are valid.

Summary of Background Data. Sacroiliac joint dysfunction is a subject of controversy. The validity of different sacroiliac joint tests is unknown. Long-standing therapeutic tradition is to manipulate supposed dysfunctions of the sacroiliac joint. Many manual therapists claim that their good clinical results are a consequence of a reduction of subluxation.

Methods: Ten patients with symptoms and sacroiliac joint tests results indicating unilateral sacroiliac joint dysfunction were recruited. Twelve sacroiliac joint tests were chosen. The results of most of these tests were required to be positive before manipulation and normalized after manipulation. Roentgen stereophotogrammetric analysis was performed with the patient in the standing position, before and after treatment.

Results: In none of the 10 patients did manipulation alter the position of the sacrum in relation to the ilium, defined by roentgen stereophotogrammetric analysis. Positional test results changed from positive before manipulation to normal after.

Conclusions: Manipulation of the sacroiliac joint normalized different types of clinical test results but was not accompanied by altered position of the sacroiliac joint, according to roentgen stereophotogrammetric analysis. Therefore, the positional test results were not valid. However, the current results neither disprove nor prove possible beneficial clinical effects achieved by manipulation of the sacroiliac joint. Because the supposed positive effects are not a result of a reduction of subluxation, further studies of the effects of manipulation should focus on the soft tissue response.