Contributions
Abstract: P782
Type: Poster
Abstract Category: RIMS - Multi-disciplinary rehabilitation
Background: Postural and gait instability are common impairments in Multiple Sclerosis (MS) leading to an increased risk of falls. The Dynamic Gait Index (DGI) is a widely used clinical assessment tool measuring dynamic balance. The modified DGI (mDGI [1]) is a recently introduced scoring system which allows a more precise evaluation of the patients´ performances.
Inertial Measurement Units (IMUs) are wearable, low-cost devices which are widely used in balance disorders assessment. The aim of this study was to develop and validate an instrumented version of the mDGI to quantitatively measure dynamic balance.
Design: Cross sectional study.
Method: Ten people with MS (PwMS) with Expanded Disability Status Scale (EDSS) lower than 6.5 and mean age (Standard Deviation) of 49.5 (17.7) years and 10 Healthy Controls (HC) aged 55.1 (13.7) years were recruited. The subjects underwent clinical evaluation with the Timed Up and Go test, TUG, and mDGI. During the assessment of the mDGI tri-axial accelerometry and gyroscopic data were collected by means of a single IMU (X-sens, The Netherlands) positioned on the sternum through an elastic chest strap.
For each of the eight mDGI items, a set of quantitative features related to dynamic balance was derived from the acceleration and angular signals. Factor Analysis (Principal Components with Normalized Varimax rotation) was performed on each set, and the main Factor Score (mFS) was extracted and used as a synthetic item performance score. The Instrumented mDGI score (ImDGI) was calculated as the mean of the mFSs of the eight items. Spearman correlation coefficients were calculated between clinical (mDGI and TUG) and ImDGI scores. Mann Whitney test was used to assess differences between PwMS and HC.
Results: Median (Interquartile Range, IQR) mDGI score of PwMS and HC were respectively 37(13.75) and 64 (1) (P< 0.05). Median (IQR) ImDGI score of PwMS and HC were respectively -0.32 (0.24) and 0.36 (0.16) (P< 0.05). High correlation was found between mDGI and ImDGI (r=0.93), while moderate correlation was found between TUG and mDGI (r=-0.83) and TUG and ImDGI (r=-0.79).
Conclusions: These preliminary results suggest that the proposed method can provide a valid, quantitative and objective measure to finely detect dynamic balance disorders in PwMS. A larger sample of subjects will be enrolled to further validate our results.
Disclosure: Elisa Gervasoni: Nothing to disclose.
Gabriele Bovi: Nothing to disclose.
Denise Anastasi: Nothing to disclose.
Cristina Grosso: Nothing to disclose.
Marco Rovaris: Nothing to disclose.
Maurizio Ferrarin: Nothing to disclose.
Davide Cattaneo: Nothing to disclose.
Abstract: P782
Type: Poster
Abstract Category: RIMS - Multi-disciplinary rehabilitation
Background: Postural and gait instability are common impairments in Multiple Sclerosis (MS) leading to an increased risk of falls. The Dynamic Gait Index (DGI) is a widely used clinical assessment tool measuring dynamic balance. The modified DGI (mDGI [1]) is a recently introduced scoring system which allows a more precise evaluation of the patients´ performances.
Inertial Measurement Units (IMUs) are wearable, low-cost devices which are widely used in balance disorders assessment. The aim of this study was to develop and validate an instrumented version of the mDGI to quantitatively measure dynamic balance.
Design: Cross sectional study.
Method: Ten people with MS (PwMS) with Expanded Disability Status Scale (EDSS) lower than 6.5 and mean age (Standard Deviation) of 49.5 (17.7) years and 10 Healthy Controls (HC) aged 55.1 (13.7) years were recruited. The subjects underwent clinical evaluation with the Timed Up and Go test, TUG, and mDGI. During the assessment of the mDGI tri-axial accelerometry and gyroscopic data were collected by means of a single IMU (X-sens, The Netherlands) positioned on the sternum through an elastic chest strap.
For each of the eight mDGI items, a set of quantitative features related to dynamic balance was derived from the acceleration and angular signals. Factor Analysis (Principal Components with Normalized Varimax rotation) was performed on each set, and the main Factor Score (mFS) was extracted and used as a synthetic item performance score. The Instrumented mDGI score (ImDGI) was calculated as the mean of the mFSs of the eight items. Spearman correlation coefficients were calculated between clinical (mDGI and TUG) and ImDGI scores. Mann Whitney test was used to assess differences between PwMS and HC.
Results: Median (Interquartile Range, IQR) mDGI score of PwMS and HC were respectively 37(13.75) and 64 (1) (P< 0.05). Median (IQR) ImDGI score of PwMS and HC were respectively -0.32 (0.24) and 0.36 (0.16) (P< 0.05). High correlation was found between mDGI and ImDGI (r=0.93), while moderate correlation was found between TUG and mDGI (r=-0.83) and TUG and ImDGI (r=-0.79).
Conclusions: These preliminary results suggest that the proposed method can provide a valid, quantitative and objective measure to finely detect dynamic balance disorders in PwMS. A larger sample of subjects will be enrolled to further validate our results.
Disclosure: Elisa Gervasoni: Nothing to disclose.
Gabriele Bovi: Nothing to disclose.
Denise Anastasi: Nothing to disclose.
Cristina Grosso: Nothing to disclose.
Marco Rovaris: Nothing to disclose.
Maurizio Ferrarin: Nothing to disclose.
Davide Cattaneo: Nothing to disclose.