The Reliability and Validity of the Computerized Double Inclinometer in Measuring Lumbar Mobility

Joy Christine MacDermid*, 1, Vanitha Arumugam 2, Joshua Israel Vincent 2, Krista L Carroll 3
1 McMaster University, School of Rehabilitation Science, Hamilton, Ontario, Canada; Roth-MacFarlane Hand and Upper Limb Center, St. Joseph’s Hospital, London, Ontario, Canada
2 University of Western Ontario, Health and Rehabilitation Sciences, Faculty of Health Sciences, London, Ontario, Canada
3 School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 1317
Abstract HTML Views: 512
PDF Downloads: 324
Total Views/Downloads: 2153
Unique Statistics:

Full-Text HTML Views: 680
Abstract HTML Views: 340
PDF Downloads: 229
Total Views/Downloads: 1249

Creative Commons License
© MacDermid et al.; Licensee Bentham Open.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License ( which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.

* Address correspondence to these authors at the DB-222 Roth – MacFarlane Hand and Upper Limb Center, St Joseph’s Healthcare London, London, ON N6A 4L6, Canada; Tel: +1-519-646-6100, Ext. 64636; Fax: +1-519-646-6049; E-mail:


Study Design :

Repeated measures reliability/validity study.

Objectives :

To determine the concurrent validity, test-retest, inter-rater and intra-rater reliability of lumbar flexion and extension measurements using the Tracker M.E. computerized dual inclinometer (CDI) in comparison to the modified-modified Schober (MMS)

Summary of Background :

Numerous studies have evaluated the reliability and validity of the various methods of measuring spinal motion, but the results are inconsistent. Differences in equipment and techniques make it difficult to correlate results.

Methods :

Twenty subjects with back pain and twenty without back pain were selected through convenience sampling. Two examiners measured sagittal plane lumbar range of motion for each subject. Two separate tests with the CDI and one test with the MMS were conducted. Each test consisted of three trials. Instrument and examiner order was randomly assigned. Intra-class correlations (ICCs 2, 2 and 2, 2) and Pearson correlation coefficients (r) were used to calculate reliability and concurrent validity respectively.

Results :

Intra-trial reliability was high to very high for both the CDI (ICCs 0.85 - 0.96) and MMS (ICCs 0.84 - 0.98). However, the reliability was poor to moderate, when the CDI unit had to be repositioned either by the same rate (ICCs 0.16 - 0.59) or a different rater (ICCs 0.45 - 0.52). Inter-rater reliability for the MMS was moderate to high (ICCs 0.75 - 0.82) which bettered the moderate correlation obtained for the CDI (ICCs 0.45 - 0.52). Correlations between the CDI and MMS were poor for flexion (0.32; p<0.05) and poor to moderate (-0.42 - -0.51; p<0.05) for extension measurements.

Conclusion :

When using the CDI, an average of subsequent tests is required to obtain moderate reliability. The MMS was highly reliable than the CDI. The MMS and the CDI measure lumbar movement on a different metric that are not highly related to each other.

Keywords: Computerized dual inclinometer, low back pain, modified-modified Schober, reliability, construct validity..