Article

Custom carbon-fiber composite ankle foot orthoses (AFOs) have been
anecdotally reported to improve gait of Charcot-Marie-Tooth (CMT) patients. The purpose of the study was to characterize the spatio-temporal, joint kinetic and
mechanical responses of a custom carbon fiber AFO during locomotion for persons
diagnosed with CMT. METHODS: Eight volunteers were fitted with custom AFOs. Three
of the devices were instrumented with eight strain gauges to measure surface
deformation of the shell during dynamic function. Following a minimum 10 weeks
accommodation period, plantar- and dorsiflexor strength was measured bilaterally.
Volunteers then walked unbraced and braced, at their preferred pace over a force
platform and instrumented walkway while being tracked with a 12-camera motion
capture system. Strength, spatio-temporal and lower extremity joint kinetic
parameters were evaluated between conditions (single subject) using the model
statistic procedure. Mechanical loads were presented descriptively. RESULTS: All
participants walked faster (89.4 +/- 13.3 vs 115.6 +/- 18.0 cm/s) in the braced
condition with ankle strength negatively correlated to speed increase. As Delta
velocity increased, maximum joint moments during loading response shifted from
the hip joint to the ankle and knee joints. During propulsion, the hip joint
moment dominated. Subjects exhibiting the greatest and least Delta velocity
imposed an average load of 54.6% and 16.6% of body weight on the braces,
respectively. Energy storage in the brace averaged 9.6 +/- 6.6J/kg. CONCLUSION:
Subject-specific effects of a custom AFO on gait for CMT patients were
documented. The force-deflection properties of carbon-fiber composite braces may
be important considerations in their design.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS