Determination of loads carried by polypropylene ankle-foot orthoses: A preliminary study
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Accepted version
Author(s)
Papi, E
Maclean, J
Bowers, RJ
Solomonidis, SE
Type
Journal Article
Abstract
Ankle–foot orthoses (AFOs) are prescribed for the management of gait-related problems. Prescription of AFOs is based
on empirical techniques due to the low level of evidence-based research on their efficacy, but primarily poor understanding
of their mechanical characteristics. This study aimed to establish a method that would allow the quantification of the
contribution of AFOs in the control of the ankle joint during gait. A possible way of achieving this aim would be to measure
strain on the AFO during walking by the use of strain gauges. Following successful experimentation with the application
of strain gauges to polypropylene tensile specimens, an AFO was instrumented by attaching strain gauges to it so as
to allow the moment generated on the AFO in the sagittal plane about the ankle to be measured. Walking trials using
this AFO on an able-bodied subject indicated good step-to-step repeatability. The use of an instrumented AFO in conjunction
with kinematic and kinetic data acquisition would allow the contribution of the AFO and the residual anatomical
loads to be determined. The advantage of such procedure over previously reported ones resides on the use of the actual
orthosis being worn by patients thereby conducting tests under real-life situations. It is believed that such analysis of the
load actions of an orthosis, which may in future be carried out in three dimensions, would allow a better understanding
of the interaction between the leg and the orthosis. This should ultimately enhance AFO prescription criteria and help
in optimising patient/device matching.
on empirical techniques due to the low level of evidence-based research on their efficacy, but primarily poor understanding
of their mechanical characteristics. This study aimed to establish a method that would allow the quantification of the
contribution of AFOs in the control of the ankle joint during gait. A possible way of achieving this aim would be to measure
strain on the AFO during walking by the use of strain gauges. Following successful experimentation with the application
of strain gauges to polypropylene tensile specimens, an AFO was instrumented by attaching strain gauges to it so as
to allow the moment generated on the AFO in the sagittal plane about the ankle to be measured. Walking trials using
this AFO on an able-bodied subject indicated good step-to-step repeatability. The use of an instrumented AFO in conjunction
with kinematic and kinetic data acquisition would allow the contribution of the AFO and the residual anatomical
loads to be determined. The advantage of such procedure over previously reported ones resides on the use of the actual
orthosis being worn by patients thereby conducting tests under real-life situations. It is believed that such analysis of the
load actions of an orthosis, which may in future be carried out in three dimensions, would allow a better understanding
of the interaction between the leg and the orthosis. This should ultimately enhance AFO prescription criteria and help
in optimising patient/device matching.
Date Issued
2015-01-01
Date Acceptance
2014-12-11
Citation
Proceedings of the Institution of Mechanical Engineers Part H - Journal of Engineering in Medicine, 2015, 229 (1), pp.40-51
ISSN
0954-4119
Publisher
SAGE Publications (UK and US)
Start Page
40
End Page
51
Journal / Book Title
Proceedings of the Institution of Mechanical Engineers Part H - Journal of Engineering in Medicine
Volume
229
Issue
1
Copyright Statement
© Sage 2015. The final publication is available via Sage at https://dx.doi.org/10.1177/0954411914566630
Subjects
Science & Technology
Technology
Engineering, Biomedical
Engineering
Ankle-foot orthosis
strain gauges
ankle moment
orthotic loads
walking
HUMAN JOINT MOTION
STRESS-ANALYSIS
ISB RECOMMENDATION
STIFFNESS
DROP
GAIT
SPINE
HIP
Publication Status
Published