A comparison of methods for measuring trunk list. A simple plumbline is the best

Abstract

Study design: Trunk list was measured using three different techniques to compare accuracy, precision, and ease of use.

Objective: To obtain a reproducible technique for further studies of the nature, cause, and clinical relevance of trunk list.

Summary of background data: Gravity-induced trunk list is a clinical sign that is frequently observed in patients with low back pain and has been associated with intervertebral disc lesions.

Methods: Patients with trunk list participated in a comparison of three techniques to determine list magnitude and direction. Paired measurements of trunk list were obtained from each patient using three techniques: a plumbline, a projected shadow, and the 3SPACE Isotrak (McDonnell Douglas Electronics Company, Colchester, VT). In addition, intra- and interobserver reliability of list measurement was assessed by comparison of paired measurements by each of two observers.

Results: List measurements assessed by the plumbline and the projected shadow techniques were not significantly different, but the Isotrak produced data that differed significantly (P < 0.05) from both of these techniques. Comparison of intra- and interobserver repeatability of list measurement using the plumbline technique indicated no significant difference between repeated measures by each observer or between two observers.

Conclusions: A plumbline is the most useful instrument for measuring static trunk list, but its limitations and the need for standardization of measurement technique must be recognized.