OBJECTIVE:

a) Establish a precise, standardized method to assess prone leg alignment changes (functional “leg length inequality”), which have, until now, been reported clinically to occur as a result putative chiropractic subluxation isolation tests [neck flexion (C5) and extension (C1)]; and b) describe differences in leg alignment changes in a group of healthy subjects and patients with chronic spinal complaints.

DESIGN:

Two group, two isolation tests, descriptive, repeated measure analysis of variance.

SETTING:

Exercise and Sport Research Institute, Arizona State University.

PARTICIPANTS:

Eight healthy controls, eight patients with a history of chronic spinal complaints and observable leg alignment reactivity.

INTERVENTIONS:

Active cervical flexion/extension maneuvers.

OUTCOME MEASURES:

Optoelectric markers affixed to heels and occiput, as subjects lay prone. Marker locations sampled at 100 Hz for 10 sec during: a) three no movement trials, b) three cervical extension and c) three flexion trials. Data transformed to local reference frame approximately each subject’s longitudinal axis prior to analysis.

RESULTS:

Heel position movement occurred during trials and were highly individualistic. Patients exhibited more asymmetrical movements than the controls during the head-up trials. No differences existed between controls and patients for range of heel displacement or net displacement.

CONCLUSIONS:

The results of this study allow the following to be concluded: 1) small leg displacements (< 1 mm) were recorded by the optoelectric measurement system; 2) heel position changes during isolation tests were identifiable; 3) as a result of head-up maneuvers, patients exhibited more asymmetrical heel movement than controls (t = 8.743, p < .01); 4) The heel range of motion was not different between the groups; and 5) The net change in heel position was not different between the groups. Patients exhibited more asymmetrical heel motion during head-up isolation tests, suggesting that some phenomena may separate these two groups, warranting future study.

J Manipulative Physiol Ther. 1994 Oct;17(8):530-8. [PMID:7836876]

Author information: De Witt JK, Osterbauer PJ, Stelmach GE, Fuhr AW. Exercise and Sport Research Institute, Arizona State University, Tempe 85287-0404.