Date of Award


Document Type

Scholarly Project

Degree Name

Master of Physical Therapy (MPT)


Physical Therapy

First Advisor

Peggy Mohr


Lumbar Vertebrae; Reproducibility of Results


Purpose: The purpose of this study was to determine the intra- and inter-tester reliability of the DualerTM Digital Inclinometer when measuring lumbar flexion and extension. Past studies examining reliability of inclinometers have reported variable results. Few studies in the literature have sought to determine the reliability of the Dualer™ Digital Inclinometer for measuring lumbar flexion and extension.

Methods: The subjects who participated in this study were university students between 20 and 41 years of age without a significant history of back pain (n=22). Two testers measured each subject's lumbar flexion and extension, hip flexion and extension, and straight leg raise during each of two measuring sessions.

Results: Intraclass correlation coefficients (ICC) as an indication of intra-tester reliability for lumbar flexion, extension and total motion for tester one were .59, .73, and .76 respectively. ICC values for lumbar flexion, extension and total motion for tester two were .67, .74, and .70, respectively. Inter-tester reliability was not established because of insufficient intra-tester reliability.

Discussion: Many factors may have contributed to the lack of high intra-tester reliability. The subject, tester, and sensitivity of the instrument or procedure may have caused errors. In order to use the Dualer™ with the currently recommended procedure clinically, the clinician must be aware of the limitations and seek to minimize the sources of error.