Active dorsiflexing prostheses may reduce trip-related fall risk in peoplewith transtibial amputation

摘要

People with amputation are at increased risk offalling compared with agematched, nondisabled individuals.This may partly reflect amputationrelated changes to minimumtoe clearance (MTC) that could increase the incidence oftrips and fall risk. This study determined the contribution of anactive dorsiflexing prosthesis to MTC. We hypothesized thatregardless of speed or incline the active dorsiflexion qualitiesof the ProprioFoot would significantly increase MTC anddecrease the likelihood of tripping. Eight people with transtibialamputation walked on a treadmill with their current foot attwo grades and three velocities, then repeated the protocol after4 wk of accommodation with the ProprioFoot. A mixedmodel,repeatedmeasures analysis of variance was used to compareMTC. Curves representing the likelihood of tripping werederived from the MTC distributions and a multiple regressionwas used to determine the relative contributions of hip, knee,and ankle angles to MTC. Regardless of condition, MTC wasapproximately 70% larger with the ProprioFoot (p < 0.001) andthe likelihood of tripping was reduced. Regression analysisrevealed that MTC with the ProprioFoot was sensitive to allthree angles, with sensitivity of hip and ankle being greater.Overall, the ProprioFoot may increase user safety by decreasingthe likelihood of tripping and thus the pursuant likelihoodof a fall.