MyLeg P1: The functional evaluation of a ankle prosthesis prototype for osseointegrated transfemural amputees

People with a transfemoral amputation experience a higher metabolic cost and
cognitive load during walking. This is mainly due to the absence of an active
knee and ankle. To resolve these challenges, a fully passive, energy efficient
and lightweight prototype prosthesis has been developed. Using new materials
with a higher energy storage capacity, the prototype prosthesis is able to
store and release more power during push-off than conventional ankle devices.
Making the push-off power better approximate to the push-off power of
able-bodied people. Measurements will be done to confirm if the design of the
prototype is adequate and attains the pre-set goals.

To evaluate the performance of the newly-developed prosthesis (prototype)
during walking in people with a transfemoral osseointegration implant. This
will be done using lab-based measurement, evaluating metabolic cost, walking
capacity, gait pattern, functionality, and participant*s experience.

This study design includes a pre-test in the morning (with the participant*s
own prosthesis), an introduction and familiarisation period with the new
prototype and a post-test in the afternoon.

An introduction and practice with the prosthesis prototype inside the
Radboudumc under supervision of a physiotherapist, researcher, orthopaedic
technician, and the manufacturer.

The participants are asked to visit once for a full day (8 hours). During the
day, participants are asked to perform activities like standing sitting and
walking, whereof the risk and burden for the subjects are minimal. After the
pre-test, participants are asked to use newly-developed prosthesis ankle. The
use of this prosthesis prototype can cause discomfort. Walking with the new
prototype can feel uncomfortable, mostly at the beginning of practice with the
prototype. The use and getting used to a new prosthesis, like this prototype,
may also cause muscle strain. Although the prosthetic foot prototype has been
extensively tested for safety and use, the unlikely event that the prototype
may break could cause a participant to fall. However, the researcher and
physical therapist will always be present and next to the participant during
the day to prevent this. During the pre- and post- test, the participants will
wear a safety-harness, which will prevent them from harm in the event of a
fall.

This research has the potential to provide an objective evaluation of the
design and build of the newly-developed prosthesis in comparison to the
currently used prosthesis. This knowledge will be used to further develop and
improve the improve the consecutive prototypes in the MyLeg project (ERC-H2020
n.780871).