38 How two-dimensional representations of three-dimensional human movement can be misleading

Abstract

Gait temporal-spatial variability and step regularity as measured by trunk accelerometry, measures relevant to fall risk and mobility, have not been well studied in individuals with lower-limb amputations. The study objective was to explore the differences in gait variability and regularity between individuals with unilateral transtibial amputations due to vascular (VAS) or nonvascular (NVAS) reasons and fall history over the past year. Of the 34 individuals with trans-tibial amputations who participated, 72% of the 18 individuals with VAS and 50% of the 16 individuals with NVAS had experienced at least one fall in the past year. The incidence of falls was not significantly different between groups. Variability measures included the coefficient of variation (CV) in swing time and step length obtained from an electronic walkway. Regularity measures included anteroposterior, medial-lateral and vertical step regularity obtained from trunk accelerations. When controlling for velocity, balance confidence and time since amputation, there were no significant differences in gait variability or regularity measures between individuals with VAS and NVAS. In comparing fallers to nonfallers, no significant differences were found in gait variability or regularity measures when controlling for velocity and balance confidence. Vertical step regularity (p = 0.026) was found to be the only significant parameter related to fall history, while it only had poor to fair discriminatory ability related to fall history. There is some indication that individuals who have experienced a fall may walk with decreased regularity and this should be explored in future studies.