Comparison of Two Handheld Digital Dual Inclinometry Techniques in the Measurement of Lumbar Flexion Active Range of Motion.

Context: An accurate assessment of lumbar spine active range of motion (AROM) is clinically important. Dual inclinometry is recommended as the optimal technique for measuring lumbar flexion AROM; however, the procedures differ in the literature.

Objective: To compare 2 different handheld digital dual inclinometry (HDDI) techniques for evaluating lumbar flexion AROM.

Design: The study was a repeated-measures design consisting of 2 trials.

Setting: Laboratory.

Participants: A sample of 69 adult volunteers (28 men and 41 women; mean age 23.8 [2.4] y) without pain or injury to their back, hips, or abdomen for at least 3 months participated in the study.

Intervention: Using standardized methods, 1 trained tester performed 2 different HDDI measurements of standing lumbar flexion AROM on each subject. Each subject performed one repetition of AROM lumbar flexion per HDDI measurement. The HDDI measures differed in the process for placing the upper inclinometer, with one technique identifying the upper landmark by skilled palpation of the T12 spinous process and the other technique by measuring 15-cm cephalad to the S2 region landmark to approximate the location of the T12 spinous process.

Main Outcome Measures: A dependent t test, Pearson correlation coefficient (r), the 95% limits of agreement, and Bland-Altman plots were used to examine agreement between the techniques.

Results: Dependent t testing showed no significant differences between the techniques (mean difference = 1.2°, P = .11). A strong correlation existed between the 2 HDDI techniques (r = .80, P < .001). The Bland-Altman plot illustrated that 64 of the 69 data points were within the 95% limits of agreement for the 2 techniques.

Conclusions: The findings suggest that HDDI measurements of lumbar flexion AROM are comparable when using either of the 2 HDDI techniques described. Clinicians can make an evidence-based choice for using either method of measuring lumbar flexion AROM.