Article

A solid-ankle cushioned heel (SACH) foot is a non-joint foot without natural
ankle function. Transtibial amputees may occur toe scuffing in the late swing
phase due to a lack of active dorsiflexion. To address this problem, clinical
guidelines suggests shortening the pylon to produce a smooth gait. However, this
causes a leg length discrepancy, induces asymmetry in the hip joint, and causes
an overload of L5/S1 joint force. Therefore, this study aimed to investigate the
influence of different prosthesis pylons on the hip joint and L5/S1 joint forces.
Ten subjects were recruited using leg length for normalisation. Four different
pylon reductions (0%, 1%, 2%, and 3%) were used for gait analysis. A Vicon system
and force plates were used to collect kinematic data and ground reaction force,
respectively. The software package MATLAB was used to create a mathematical model
for evaluating the symmetry and force of the hip joint and the low back force of
the L5/S1 joint. The model was validated by the correlation coefficient
(CC=0.947) and root mean square (RMS=0.028 BW). The model estimated that the 1%
group had a symmetrical hip joint force and a lower L5/S1 joint force in the
vertical direction. This study indicates that a 1% pylon shortening on a SACH
prosthesis is appropriate for a trans-tibial amputee.
CI - Copyright (c) 2014 Elsevier B.V. All rights reserved.

Langue : ANGLAIS