Leg Length Alignment Asymmetry In A Non-clinical Population And Its Correlation To A Decrease In General Health As Measured By The SF-12: A Pilot Study
Gary A. Knutson, DC, Edward F. Owens, Jr., MS, DC
Journal of Vertebral Subluxation Research ~ November 1, 2004 ~ Pages 1-5
Purpose: To determine if there is an association between a test commonly used by chiropractors as a sign of subluxation/joint dysfunction – supine leg length alignment (LLA) asymmetry – and health-related quality of life as measured by the SF-12 questionnaire, in a non-clinical population.
Design: Volunteers answered the SF-12 and background questionnaires and were then examined for supine LLA by a chiropractor blinded to their answers.
Setting: Gatherings of people in the general population. Participants: Fifty-five unscreened volunteers.
Examiner: Chiropractor with approximately 20 years of clinical experience.
Main Outcome Measures: The association of supine LLA asymmetry with general health based on the two summary scores – physical (PCS) and mental (MCS) – of the SF-12.
Results: There were 27 volunteers with LLA asymmetry, they had a mean PCS of 49.6 and a mean MCS of 47.9. In the no-LLA asymmetry group (n=23) the mean PCS was 50.8, and mean MCS of 54.0. A multiple regression analysis found that of the variables gender, age, back pain (current/former) and LLA asymmetry, the only factor to approach significance with the SF-12 MCS/PCS was the presence of LLA asymmetry. A t-test found there was a significant difference (p=0.017) in the MCS between the supine LLA asymmetry and no-LLA asymmetry groups.
Conclusion: This pilot study suggests that in this group of volunteers (n=50) from the non-clinical general population, those who demonstrated a commonly used sign of subluxation/joint dysfunction – supine leg length alignment asymmetry – had a significantly (P=0.017) lower measure of general health as determined by the SF-12 survey than those volunteers without such asymmetry. Further investigation to clarify this relationship and to establish whether there is a connection between the putative entity of chiropractic subluxation and unloaded leg length alignment asymmetry is recommended.
Key Indexing Terms: Leg length inequality, Chiropractic, SF-12, quality of life