J Manipulative Physiol Ther. 2002 Feb; 25(2): 110E.

Incidence of foot rotation, pelvic crest unleveling, and supine leg length alignment asymmetry and their relationship to self-reported back pain.

Knutson GA.

OBJECTIVE: To determine the incidence of pelvic unleveling, foot rotation, and supine leg length alignment asymmetry in a nonclinical population and to examine the validity (sensitivity, specificity, positive and negative predictive values) of these visual tests and their relationship to self-reported back pain. DESIGN: Volunteers answered a questionnaire regarding back pain and were then examined by a chiropractor who was unaware of the status of their back pain. PARTICIPANTS: Seventy-four unscreened volunteers answered the questionnaire. MAIN OUTCOME MEASURES: The association of visual tests with back pain and their validity indices; Visual Analogue Scale ratings. RESULTS: Fifty-one percent (n = 74) of volunteers examined had supine leg length alignment asymmetry (LLA). Pain intensity on a Visual Analogue Scale was significantly higher (P <.001) for those demonstrating supine LLA than for those without LLA. Those with back pain and recurrent back pain were significantly (P <.001) more likely to have supine LLA. The validity indices of the supine leg check showed acceptable levels for sensitivity (74%), specificity (78%), and positive predictive value (82%) [corrected] in recurrent back pain. Findings also indicated a high incidence of supine LLA in volunteers with chronic back pain (85%). CONCLUSION: The results indicated that, in this group of volunteers, the supine leg length alignment check had clinical validity as a stand-alone test for recurring back pain. Further testing on a larger, statistically defined cross-section of the population is recommended.