Executive Summary
The Niagara foot was developed as part
of the landmine victims relief programme of The Canadian
Centre for Mine Action Technology (CCMAT) by Niagara Prosthetics
and Orthotics (St. Catherines, ON) and Queen’s University
(Kingston, ON) with the collaboration of Dupont Engineering
Polymers (Wilmington, DE) and Recto Molded Products (Cincinnati,
OH). With the assistance of the Thailand Mine Action Centre
(TMAC), a study team visited Aranyaprathet Hospital from
November 1, 2001 to November 10, 2001 to perform a clinical
trial on 15 volunteer subjects. A follow-up protocol was
developed to permit a patient review at 3 months by local
prosthetists with communication of results by electronic
and air mail. At 6 months, a study team from Canada visited
the clinic to interview patients and to observe the foot
components directly. The one-year study will be completed
in a final visit to Aranyaprathet in December 2002. The results
of the initial study are detailed in a separate document:
Technical Report – Niagara Foot Pilot Study in Thailand.
(January 2002). This report documents the results of the
3-month and 6-month follow-up studies.
The Niagara Foot is
a low-cost energy-return system. The biomechanical advantages
of the device compared to SACH designs were evident in
initial trials and continue to improve with time. Patients
are able
to detect and appreciate the performance offered by this
device, particularly in its ability to return energy during
the gait cycle, thereby decreasing the muscular effort
required for walking. These conclusions are partially borne
out by
objective measures of walking performance indicating a
reduced cadence and increased stride length compared to the
original
SACH foot in patients.
The flexibility of the heel is a concern
for some patients. Increased flexibility under load and
during standing suggests to some a lack of stability for
activities
on uneven terrain. However, the gait performance results
at six months suggest that patients are becoming more confident
with the foot. The Niagara Foot also increases the loading
to other components in the prosthetic system, sometimes
causing failure. As such, its use as a retrofit device on
older systems
should be carefully considered.
The durability of the device
is evident. In contrast to the SACH device currently used
at the Aranyaprathet Clinic, there were no failures of
the keel after six months in all patients, which is consistent
with laboratory testing. Devices showed a limited amount
of wear in contact regions and a small permanent upward
deformation
in the heel region. However, there were a number of failures
in the cosmetic foot cover. In the next phase of the project,
this will be redesigned to reduce the tendency to rip,
retain water, and make it difficult to fit into athletic
and dress
footwear. |
 Download
PDF
(Main report: 885
k)
Download
PDF
(Appendices:
933 k)
|
