Instrumented version of the modified dynamic gait index in subjects with neurological disorders.

BACKGROUND: Gait instability is common in adults with neurological disorders and the modified Dynamic Gait Index (mDGI) was recently introduced to assess dynamic balance. However, instrumental assessment is needed to provide quantitative measures.

OBJECTIVE: to develop and validate an instrumented version of the mDGI.

DESIGN: cross sectional study.

SETTING: clinical setting PARTICIPANTS: 30 adults with neurological disorders (10 with multiple sclerosis, 10 with Parkinson disease and 10 with stroke) and 20 healthy volunteers.

METHODS: Participants were assessed with the Timed Up and Go test (TUG) and with the mDGI. During the assessment of mDGI, data were collected by a single Inertial Measurement Unit (IMU) positioned on the sternum. Principal Component (PC) Analysis (A) was performed on the instrumented data extracting eight PC scores (ImPC) describing dynamic balance. The instrumented overall score (ImDGI) was then calculated as the sum of the mPCs. PCA revealed 2 components associated with stride features and regularity (ImDGI_Gait_Pattern) and trunk movements (ImDGI_Trunk_Sway). Spearman coefficients were calculated between mDGI and ImDGI while Mann Whitney (U) and Kruskal-Wallis (H) tests assessed differences between groups and neurological conditions.

MAIN OUTCOME MEASUREMENT: Instrumented modified Dynamic Gait Index (ImDGI) RESULTS: ImDGI did not show ceiling effects and good correlations were found between ImDGI and mDGI (r=0.84), and TUG (r=0.84) for people with neurological disorders, P<.001. Significant differences among pathologies (Htest(2) =12.5, P=.002) and between healthy participantsand adults with neurological disorders (Utest=47.0, P=.001) were found. ImDGI_Trunk_Sway discriminated between people using or not using walking aids and among the three pathologies (H(2) =10.0, P=.007).

CONCLUSIONS: The ImDGI test seems to provide valid measures to objectively assess dynamic balance in neurological conditions and possibly quantifying balance deficits also in adults with neurological disorders. This article is protected by copyright. All rights reserved.