Using Sensorimotor Reorganization Following Upper Limb Amputation to Improve Prosthetic Control

Union de Gestion des Etablissements des Caisses d'Assurance Maladie - Nord Est50 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Amputation of Upper Limb Agenesis of Upper Limb

Interventions

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.

MappingOTHER

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.

Prosthetic controlOTHER

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.

Use of motor reorganization and compensationOTHER

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.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * people aged 18 or more * amputation or agenesis of one uper limb, above the wrist or higher * understanding of the French language and the ability to express onself in that language (for semi-structured interviews) * affiliation to a social security programm Exclusion Criteria: * history of progressive psychiatric or neurological disorders or disorders with residual effects * pregnant or breastfeeding woman * minor * an adult under legal guardianship * pain influencing movement (trunk, residual limb, phantom limb, contralateral limb)

Outcomes

Primary Outcomes

Characterization of phantom limb

Semi-structured interview to elicit patients' descriptions of phantom sensations

Time frame: Baseline (Phase 1 session) ; optional repeat assessment at 6 months

Secondary Outcomes

NASA TLX Score

The cognitive load associated with the various tasks will be assessed. The higher the score, the greater the cognitive load.

Time frame: Administered at the end of each experimental sequence, up to 6 months

Southampton Hand Assessment Procedure (SHAP)

A standardized, timed questionnaire-led assessment of pathological hand function. It evaluates overall hand function and dexterity through 26 tasks, including 12 abstract object manipulations and 14 activities of daily living (ADL). Tasks are timed to calculate an overall Index of Function (IoF) scored out of 100, where higher scores reflect better hand function.

Time frame: At each evaluation session, up to 6 month

Clothespin Relocation Test (CRT)

A functional upper limb assessment measuring manual dexterity and proximal control. Participants are timed while transferring a set number of clothespins from a horizontal bar to a vertical bar (and/or vice versa) against varying spring resistances. Performance is measured by the total time taken (in seconds) to complete the task, where a shorter duration indicates better motor efficiency and coordination

Time frame: At each evaluation session, up to 6 months