Preliminary study: reliability of the spinal wheel. A novel device to measure spinal postures applied to sitting and standing.

Postural re-education is an integral part of physiotherapy management in patients with back pain. Although the link between posture and back pain is largely unknown, postural re-education is performed on the premise of optimizing spinal alignment to minimize stresses on the passive structures of the spine, to facilitate optimal muscular support and thus to prevent possible damage and further pain. A reliable and clinically meaningful measurement of spinal postures to monitor such interventions remains challenging. This study evaluated within-day (intra-tester, inter-tester) and between-day (test-retest) reliability of a novel spinal wheel device measuring thoracic and lumbar postures during sitting and standing. 17 healthy volunteers (age 39.5 +/- 5.4, BMI 25 +/- 9.2; 9 males) were measured three times, by three testers, on two separate occasions (1 week apart). The angular change between C7 and T12 and between T12 and S1 provided thoracic and lumbar curvatures, respectively. Intra-class correlation coefficient (ICC) with 95% confidence intervals and typical error were calculated. Excellent reliability was demonstrated with intra-tester ICCs between 0.947 and 0.980 and typical error between 1.7 degrees and 3.7 degrees and inter-tester ICCs between 0.949 and 0.986 and typical error between 2.0 degrees and 4.7 degrees. Test-retest reliability was high with ICCs 0.719-0.908 and typical error between 4.0 degrees and 7.4 degrees. In conclusion, the spinal wheel demonstrated excellent within-day and high between-day reliability. The device may be used in conjunction with 2D camcorder to provide clinically useful visual evaluation of postures for assessment, intervention monitoring, and feedback during postural re-education.