The effect of a talux® prosthetic foot on gait parameters and limb loading of nonvascular transtibial amputees

Authors:

• Terry Supan,
• Maria Lebiedowska,
• Robert Dodson,
• Steven Verhulst,
• Michelle Dufour

Abstract

The Talux® prosthetic foot is designed to combine the benefit provided by a dynamic response foot with the advantage of added dorsiflexion, plantarflexion, inversion, and eversion, thus closely simulating the normal human foot. Patients have found that the design also accommodates for small changes in heel height. Previous studies comparing the Talux with other prosthetic feet did not report the similarities between the prosthetic and the sound side. The aim of the study was twofold: to determine the similarities in gait parameters between the prosthetic and sound sides and to determine how much change in heel height can be accommodated by the Talux prosthetic foot. To achieve this aim, we evaluated selected gait parameters. We compared the spatial and temporal gait parameters, hip, knee, and ankle kinematics, and knee kinetics on the prosthetic versus sound side, and we compared the parameters when patients were walking with different lifts under the heels in 10 nonvascular amputees wearing the Talux.We found similarities between the prosthetic and sound sides of the subjects in the majority of the gait parameters except for 1) longer step length and shorter step time, 2) more extended knee at initial and mid stance, and 3) larger range of knee motion in swing phase of walking, all on the prosthetic side. The vertical ground reaction forces were only 10% higher on the prosthetic side. The change in the heel height from 0 to 24 mm was accommodated for most of the parameters except for the increased knee flexion at initial and mid stance on the prosthetic side without any effect on the sound side. Of significance was that the major differences between the Talux and the sound side foot were only found during swing phase when there was no interaction between the prosthetic foot and the ground. This data suggests that the dynamic properties of the Talux foot mimic the properties of the anatomical foot. Copyright © 2009 American Academy of Orthotists and Prosthetists.