Intermanual transfer using a mental imagery program in prosthetic training

Rationale: To improve the rate of use of prosthetic devices in adults with an upper limb amputation intermanual transfer might be helpful. Intermanual transfer is the ability to transfer motor skills from one, trained side to the other side (Hicks, 1983). This can be used in upper limb amputees by training the unaffected arm while waiting for the prosthesis to be fitted. Especially because it is assumed that starting to train early after the amputation will lead to better acceptance and improved prosthetic handling (Malone, Fleming et al. 1984). By using intermanual transfer, the prosthetic skills of the affected arm will improve. Intermanual transfer effects were demonstrated to be present in myoelectric (Romkema, Bongers et al. 2013) and body-powered prosthesis use (Weeks, Wallace et al. 2003). To further optimize the effects we compared the effect of training of different test tasks and the spacing over time in recent studies. The (preliminary) findings of these studies show that the intermanual transfer effects are small. We would like to add a mental imagery program to increase the effects of the intermanual transfer.
Objective: 1)To compare the effects of intermanual transfer with and without mental imagery. 2) To find out the effects of intermanual transfer with intermanual transfer in patients.
Study design: 1) experiment 1 is a non-blinded randomized trial, 2) experiment 2 is a case series
Study population: 1) 48 non-amputated adults, 2) two amputees who will start to use the myo-electric prosthesis for the first time.
Intervention (if applicable): 1) Two of three groups of 16 participants train to use a prosthesis simulator, one only using intermanual transfer and one using both intermanual transfer and mental imagery. A third group gets a sham training, without using the prosthesis simulator. In experiment 2, two patients with an amputation train (6 times 30 min) with the prosthetic simulator on the unaffected arm. The prosthesis simulator mimics the functioning of a real prosthesis but can be worn by able-bodied participants and at the sound arm of a patient with an upper limb amputation. The prosthesis simulator places a prosthetic hand in front of the sound hand.
Main study parameters/endpoints:
- Grip force control: mean deviation of the asked force in N.
- Movement time: time taken to execute the movement in s.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness:
The participants will use the prosthesis simulator to execute activities. This simulator mimics a real prosthetic device and can be worn over a sound arm. With the use of this simulator we are able to test more participants than only a few patients with an amputation who will start using a myoelectric prosthesis for the first time. Importantly, all the measurements are non-invasive and the use of a prosthesis simulator is not different from wearing a regular prosthesis. Therefore, the risks associated with participation can be considered negligible and the burden can be considered minimal.

Using mental imagery, the intermanual transfer training for prosthetic users can be improved.

The first experiment will take place in April, May, June. The patients will be measured inbetween June and December.

In experiment 1 , three groups of 12 participants train to use an prosthetic simulator on 5 consecutive days for 45 minutes. One group trains, beside intermanual transfer also mental imagery, where using mirror therapy and motor imagery, movements are learned by imagining these. In experiment 2 patients with an upper limb amputation train the unaffected hand with the prosthetic simulator. The prosthetic simulator mimics a real prosthesis, though can be worn on the sound arm. The prosthetic hand of the simulator is placed in front of the sound hand.