Influence of different types of feedback for learning to control grip force with a myo-electric prosthetic simulator

People with an upper extremity amputation often choose to have fitted a
prosthesis to restore the functionality for as best as possible. However, the
rejection rate of prosthetic devices is high, mainly due to a low degree of
functional use (Biddis and Chau, 2007; Dudkiewicz et al., 2004; Kyberd et al.,
1998; Plettenburg, 2002). This functional use can be enhanced by training
(Carter, Torrance and Merry, 1969; Lake, 1997; Weeks, Anderson and Wallace,
2003). We expect that by enhancing the functional use through training, the
overall use of prostheses will be enhanced. Currently, prosthetic training in
rehabilitation centre is not evidence-based but mainly based on own
experiences. In this study we will focus on a specific part of a training, the
feedback one has to receive to learn to use the prosthesis as good as possible
During this study, the focus of learning is on the force control of a
myo-electric prosthesis.

The main objective of the study is to determine what type of feedback
facilitates learning to control the grip force of a myo-electric hand.

pre-test/post-test intervention

One group receives feedback in the form of knowledge of results and the other
group will receive feedback in the form of knowledge of performance. The
training is based on the app 'Angry Birds'. On a screen, a ball and goal are
showed, the ball is atached to a spring. The purpose is to get the ball into
the goal. This is done by determining a force and angle by elongating and
moving the spring. The spring is elongated by producing force on a handle with
the prosthetic hand. The angle is determined by moving the handle in the
left/right direction. In this way the ball can be released to reach the goal.

The experiment is non-therapeutic, the participants have to learn grip force
control with a prosthetic simulator during 5 training sessions. Five tests will
be administered before the first training, after the last training and during a
retention test after 2 weeks to assess the grip force control. The measurements
are non-invasive. Therefore, the risks associated with participation can be
considered negligible and the burden can be considered minimal. In this early
stage of discovering force control processes we do not want to bother the few
patients who have just been amputated. Therefore, we will use prosthetic
simulators, which mimic real prosthetic devices and can be worn over a sound
arm. With the use of the simulators we can also test more participants than
only the few recently amputated patients.