The Reliability of Standing Sagittal Measurements of Spinal Curvature and Range of Motion in Older Women With and Without Hyperkyphosis Using a Skin-Surface Device

Objective The purpose of this study was to investigate the intrarater reliability of a skin-surface instrument (Spinal Mouse, Idiag, Voletswil, Switzerland) in measuring standing sagittal curvature and global mobility of the spine in older women with and without hyperkyphosis. Methods Measurements were made in 19 women with hyperkyphosis (thoracic kyphosis angle ≥50°), mean age 67 ± 5 years, and 14 women without hyperkyphosis (thoracic kyphosis angle <50°), mean age 63 ± 6 years. Sagittal thoracic and lumbar curvature and mobility of the spine were assessed with the Spinal Mouse during neutral standing, full spinal flexion, and full spinal extension. Tests were performed by the same examiner on 2 days with a 72-hour interval. The intrarater reliability of the measurements was analyzed using the intraclass correlation coefficient, standard error of measurement and minimal detectable change. Results Intraclass correlation coefficients ranged from 0.89 to 0.99 in both groups. The standard errors of measurement ranged from 1.02° to 2.06° in the hyperkyphosis group and from 1.15° to 2.22° in the normal group. The minimal detectable change ranged from 2.85° to 5.73° in the hyperkyphosis group and from 3.20° to 6.17° in the normal group. Conclusions Our results indicated that the Spinal Mouse has excellent intrarater reliability for the measurement of sagittal thoracic and lumbar curvature and mobility of the spine in older women.