Sensory feedback prosthesis reduces phantom limb pain: Proof of a principle

BackgroundConstrained functionality and phantom limb pain (PLP) are major concerns for forearm amputees. Neuroscientific investigations of PLP suggest that behaviorally relevant stimulation of the stump can decrease PLP. Furthermore the prosthesis user could use feedback information of the prosthesis hand for optimizing prosthesis motor control when handling soft and fragile objects. Somatosensory feedback information from a prosthetic hand may therefore help to improve prosthesis functionality and reduce phantom limb pain.ObjectivesWe wanted to find out whether a two weeks training on a hand prosthesis that provides somatosensory feedback may help to improve prosthesis functionality and reduce phantom limb pain.MethodsEight forearm amputees with phantom limb pain were trained for two weeks to use a hand prosthesis with somatosensory feedback on grip strength.ResultsThe current study demonstrates a significant increase of functionality of the prosthesis in everyday tasks. Furthermore, the study shows that usage of a prosthesis that provides somatosensory feedback on the grip strength is effective to reduce phantom limb pain.ConclusionsA prosthesis with a feedback function appears to be a promising therapeutic tool to reduce phantom limb pain and to increase functionality in everyday tasks. Future studies should further investigate the scope of application of that principle.

► A hand prosthesis that provides sensory feedback is able to reduce phantom limb pain.
► Sensory feedback can be delivered via electrocutaneous stimulation of the forearm.
► Improvement of functionality of the prosthesis can be achieved during a two weeks training.
► Sensory feedback prostheses do have a high potential of acceptance in amputees.