Abstract
The Biometrics Flexible Electrogoniometer (FEG) is a lightweight device which when attached over joints can record angular displacements for periods of up to 10 hours.
The aim of this study was to examine the validity of the FEG for measuring the thoracic spine using the Cobb angle and functional activities.
12 subjects (6 F, 71±11years; 6 M, 65±11) were X-rayed in upright and “slumped” standing with the FEG attached to their thoracic spine. Three Cobb angles were obtained from the vertebrae underlying the FEG at the outer margins (OEB); the inner margins (IEB), and the mid points (MEB), of the FEG end blocks.
Comparisons of FEG and Cobb angles were derived with intraclass correlation coefficients (ICC).
In a separate experiment, 12 subjects (8F, 43±13; 4M, 35±17) performed 7 functional activities one week apart in order to assess day-to-day reliability of the FEG. Time 1 and time 2 angles were compared with an ICC.
The mean FEG angles for upright and “slumped standing” were 31±7° and 39±8° (mean ± SD) respectively. The corresponding mean OEB Cobb angles were 48±13° and 52±12°; the mean IEB Cobb angles were 24±11° and 29±10°; and the MEB Cobb angles were 36±13° and 41±10°.
The correlation between the FEG and OEB Cobb was ICC(2,1)=0.85; between FEG and IEB Cobb was ICC(2,1)=0.77 and between FEG and MEB Cobb was ICC(2,1)=0.87.
The second experiment compared day-to day reliability of the FEG when used over the thoracic spine. For the 7 activities performed: standing erect, standing slumped, reaching up, reaching down, and walking on-the-spot, the mean correlation between the measures on day 1 and day 2 was ICC(2,1)=0.96 (range 0.94 to 0.98).
This study has shown that the FEG demonstrates excellent internal and external validity in the thoracic spine. Further, it has demonstrated that the FEG measures the segment of the spine between the mid-endblocks. Future studies are planned which will use the FEG to evaluate interventions aimed at treating thoracic kyphosis
The abstracts were prepared by David AF Morgan. Correspondence should be addressed to him at davidafmorgan@aoa.org.au
Declaration of interest: b
