No abstract

Background and Purpose. The Dynamic Gait Index (DGI) is a standardized clinical assessment that aids in evaluating a subject’s ability to modify gait in response to changing demands. The purpose of this study was to use Rasch measurement theory to examine whether the DGI rating scale meets suggested psychometric guidelines, whether the hierarchical order of DGI tasks is consistent with a clinically logical testing procedure, and whether the DGI represents a unidimensional construct. Subjects. Subjects were 84 community-dwelling male veterans (age range=64–88 years; mean±SD=75±6.47 years). Methods. Data were retrieved retrospectively from the participants’ clinical records. The Rasch measurement model with the WINSTEPS program was used in this study because it offers distinct advantages over traditional psychometric approaches. Results. Overall, the DGI showed sound item psychometric properties. Each of the original 4 rating scale categories appeared to distinctly identify subjects at different ability levels. The analysis revealed a clear item difficulty hierarchical order that is generally consistent with clinical expectations. In addition, fit statistics and principal components analysis indicated that the 8 items of the DGI appear to represent a single construct. Discussion and Conclusion. The results suggest that the rating scale of the DGI is used appropriately for community-dwelling older subjects with balance problems. The findings support the continued use of this well-constructed scale for clinical and research assessment in a community-dwelling population of older subjects. [Chiu YP, Fritz SL, Light KE, Velozo CA. Use of item response analysis to investigate measurement properties and clinical validity of data for the Dynamic Gait Index.

No abstract

Fall accident is a growing concern for the aging workforce. Reducing fall injuries has been identified as a primary strategic goal in the National Occupational Research Agenda. The objective of the study was to investigate the interaction effect between aging and a novel Automated Walkway Surface Perturbation Training (AWSPT) on kinematic gait asymmetry. Five older adults and five gender-matched younger adults were involved in a laboratory study. Three- dimensional linear accelerations of left and right knee joints were measured via two Inertial Measurement Units (IMUs) during both before and after training sessions. Gait asymmetry was quantified by the percentage difference between peak knee resultant acceleration normalized to the average peak knee resultant acceleration. The results indicated significant training effect on Gait Asymmetry Index (GAI). Neither the interaction effect nor the aging effect was found to be significant. In conclusion, the current study provided evidence supporting the effectiveness of AWSPT in improving gait symmetry during normal walking. Such findings support the potential application of AWSPT in reducing risk of falling as well as in gait rehabilitation.