Using Sensorimotor Reorganization Following Upper Limb Amputation to Improve Prosthetic Control

Condition(s) studied

Investigational drug(s) / intervention(s)

Caracterisation: The objective of this phase is to identify, from a population of individuals with upper limb amputations, a sufficient number of participants who experience non-painful phenomena related to their phantom limb (sensations, mobility, etc.) prior to the subsequent phases. This phase takes the form of a semi-structured individual interview conducted by one of the study investigators.

Mapping: The objective of this phase is to study the phenomenon of induced phantom sensations in individuals who reported experiencing such sensations during the previous phase. This phase involves a systematic exploration of the areas of the residual limb whose stimulation induces non-painful phantom sensations, as well as the type of sensations thus induced.

Phantom sensations: The goal of this phase is to determine whether stimulation of the residual limb that induces sensations in the phantom limb can help people with lower-limb amputations use their prostheses more effectively.

Classification: The objective of this phase is to characterize the influence of voluntary movements of the residual limb on the myoelectric activity associated with phantom limb mobility. Myoelectric activity and cognitive load will be assessed

Prosthetic control: The objective of this phase is to evaluate the performance of a prosthetic control method based on phantom limb movement in individuals with upper limb amputations. The principle behind this method is to control the movements of the prosthesis using the corresponding movements of the phantom limb, by utilizing the myoelectric activity that can be measured on the residual limb during voluntary phantom limb movements.

motor compensations: The objective of this phase is to characterize and quantify the compensatory movements associated with the use of a conventional myoelectric upper limb prosthesis. The participant will perform the manipulation tasks defined in the SHAP method, as well as the clothespin displacement test.

Use of motor reorganization and compensation: The objective of this phase is to evaluate the performance of a prosthesis control method based on the compensatory movements associated with the use of an upper limb prosthesis. During this phase, participants will not use their personal prostheses but rather an experimental prosthesis developed by the investigators specifically for this study. The experimental prosthesis will be programmed to implement the control method based on compensatory movements, which is the focus of this evaluation.

Study summary

Amputation of an upper limb results in a disruption of the sensorimotor loop and a reorganization of the nervous system, leading to the emergence of a phantom limb and the adaptation of compensatory motor strategies. This project aims to leverage these phenomena (induced sensations, phantom mobility, and compensations) to improve control, sensory feedback, and the appropriation of prostheses, in order to reduce cognitive load and musculoskeletal disorders.

Eligibility

Primary outcome measure(s)

• Characterization of phantom limb — Baseline (Phase 1 session) ; optional repeat assessment at 6 months
  Semi-structured interview to elicit patients' descriptions of phantom sensations

Trial sites (2)

More Union de Gestion des Etablissements des Caisses d'Assurance Maladie - Nord Est trials in France