Background: The modified Dynamic Gait Index (mDGI), developed from a person-environment model of mobility disability, measures mobility function relative to specific environmental demands. The framework for interpreting mDGI scores relative to specific environmental dimensions has not been investigated.
Objective: The aim of this study was to examine the person-environmental model underlying the development and interpretation of mDGI scores.
Design: This was a cross-sectional, descriptive study.
Methods: There were 794 participants in the study, including 140 controls. Out of the total study population, 239 had sustained a stroke, 140 had vestibular dysfunction, 100 had sustained a traumatic brain injury, 91 had gait abnormality, and 84 had Parkinson disease. Exploratory factor analysis was used to investigate whether mDGI scores supported the 4 environmental dimensions.
Results: Factor analysis showed that, with some exceptions, tasks loaded on 4 underlying factors, partially supporting the underlying environmental model.
Limitations: Limitations of this study included the uneven sample sizes in the 6 groups.
Conclusions: Support for the environmental framework underlying the mDGI extends its usefulness as a clinical measure of functional mobility by providing a rationale for interpretation of scores that can be used to direct treatment and infer change in mobility function.
© 2015 American Physical Therapy Association.