Article

The effectiveness of an Ankle-Foot Orthosis footwear combination (AFO-FC) may be
partly dependent on the alignment of the ground reaction force with respect to
lower limb joint rotation centers, reflected by joint angles and moments.
Adjusting (i.e. tuning) the AFO-FC's properties could affect this alignment,
which may be guided by monitoring the Shank-to-Vertical-Angle. This study aimed
to investigate whether the Shank-to-Vertical-Angle during walking responds to
variations in heel height and footplate stiffness, and if this would reflect
changes in joint angles and net moments in healthy adults.
Ten subjects walked on
an instrumented treadmill and performed six trials while walking with bilateral
rigid Ankle-Foot Orthoses.
The AFO-FC heel height was increased, aiming to impose
a Shank-to-Vertical-Angle of 5 degrees , 11 degrees and 20 degrees , and combined
with a flexible or stiff footplate. For each trial, the Shank-to-Vertical-Angle,
joint flexion-extension angles and net joint moments of the right leg at
midstance were averaged over 25 gait cycles. The Shank-to-Vertical-Angle
significantly increased with increasing heel height (p<0.001), resulting in an
increase in knee flexion angle and internal knee extensor moment (p<0.001). The
stiff footplate reduced the effect of heel height on the internal knee extensor
moment (p=0.030), while the internal ankle plantar flexion moment increased
(p=0.035). Effects of heel height and footplate stiffness on the hip joint were
limited. Our results support the potential to use the Shank-to-Vertical-Angle as
a parameter to evaluate AFO-FC tuning, as it is responsive to changes in heel
height and reflects concomitant changes in the lower limb angles and moments.
CI - Copyright (c) 2015 Elsevier B.V. All rights reserved.

Langue : ANGLAIS