Quantification of Motor Compensation Following Biomechanical, Proprioceptive and Physiological Alterations Post-lower Limb Amputation. (QAMPA)

Lower limb amputation causes segmental loss that alters locomotor organization. The human body, designed to function in a multisegmental manner, must adapt to this new configuration where segments are missing, depending on the level of amputation. These adaptations are directly linked to the biomechanical, physiological and proprioceptive alterations caused by the loss of the amputated segments. Without mechanoreceptive afferents essential for regulating locomotion, the sensory system uses alternative information to maintain efficient locomotor function. The prosthesis partially compensates, but remains limited on the biomechanical and proprioceptive levels. Current prosthetic technologies, inspired by biomimicry, aim to imitate evolutionary solutions to restore walking, although current algorithms do not allow real-time modulation. This research aims to characterize post-amputation locomotor adaptations through biomechanical, physiological and proprioceptive exploration to develop a "locomotor characterization" model.

The study authors hypothesize that the post-amputation alterations are exacerbated in contexts of continuous and discontinuous constraints (e.g., ascent/descent and destabilization), and that the addition of a prosthesis, although inspired by biomimicry, only restores partial compensation of locomotor functions.

Study Overview

• Status: Recruiting
• Conditions: Amputation
• Intervention / Treatment: Other: Biomechanics; Other: Physiological; Other: Proprioceptive

• Study Type: Observational
• Enrollment (Estimated): 75

Contacts and Locations

• Study Contact: Name: Eric Pantera; Phone Number: 0466022536; Email: eric.pantera@chu-nimes.fr

Study Locations

• France
  • Nîmes, France, 30029
    • Recruiting
    • CHU de Nîmes
    • Principal Investigator: Eric PANTERA
    • Sub-Investigator: Nicolas RENEAUD
    • Contact: Anissa Megzari; Phone Number: 0466682536; Email: drc@chu-nimes.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Person with unilateral transtibial or transfemoral amputation and healthy volunteers for control population.

Description

Inclusion Criteria:

• The patient must have given their free and informed consent and signed the consent form
• The patient must be a member or beneficiary of a health insurance plan
• Persons with unilateral transtibial or transfemoral amputees followed in the MPR department at the Nîmes University Hospital, RRL department, Grau du Roi University Rehabilitation Hospital.
• All etiologies: vascular, traumatic and septic.
• Adapted equipment validated by the rehabilitation doctor.
• Able to walk for 5 minutes on a treadmill without technical assistance

Inclusion criteria specific to healthy volunteers:

• Adults (>18 years old) and under 40 years old
• Able to walk for 5 minutes on a treadmill without technical assistance.
• Body mass index between 18 and 25

Exclusion Criteria:

• The patient is participating in an interventional or a drug/medical device study, or is in a period of exclusion determined by a previous study
• The patient unable to express consent
• It is impossible to give the patient informed information
• The patient is under safeguard of justice or state guardianship
• Patient who has already been included in this study.
• Pregnant, parturient or breastfeeding patient.
• Appearance of a stump wound during the study requiring unloading.
• Patient for whom the implementation of vibration stimulation is not possible

Exclusion criteria for amputee patients:

• Patient suffering from uncorrected or untreated visual disorders.
• Patient with major cognitive disorders (MoCA <23).
• Patient with vestibular disorders or uncontrolled epilepsy.
• Patient with an unhealed amputation stump.
• Patient with a weight > 135kg or < 20kg
• Patients with a FAC of 1 (i.e. patients who need firm and continuous assistance from a person to support their weight and maintain balance) or less.
• Sensory impairment that makes it impossible to perceive stimulation
• Significantly reduced bone density

• Patient in whom it is impossible to correctly adjust the GRAIL System harness to the corresponding body part due to:

  • Body shape
  • Colostomy bags
  • Skin lesions that cannot be adequately protected.
  • Any other reason that prevents a good, painless adjustment of the harness.

• Patient in whom it is impossible to correctly adjust the CON-TREX System:

  • Body shape
  • Colostomy bags
  • Skin lesions that cannot be adequately protected.
  • Any other reason that prevents a good, painless adjustment of the support systems.

Exclusion criteria for healthy volunteers:

• History of significant injury or surgery affecting the lower limbs (such as hip or knee replacement or knee/ankle ligament reconstruction) that could impact walking
• History of neurological or psychiatric disorders that could affect locomotion or the processing of sensorimotor information.
• Drug treatments affecting locomotion: drugs likely to alter walking or balance, such as sedatives, muscle relaxants or neuroleptics.

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Healthy volunteers	Other: Biomechanics; Amputees and controls will be equipped with measurement sensors to record spatio-temporal, kinetic, kinematic, pressure, electromyographic and physiological parameters of gait in the movement analysis laboratory (GRAIL System). 16 Anatolog FSR sensors will be installed in the amputee population (transtibial, transfemoral on the medial, lateral, anterior and posterior parts of the stump, 4 per side, aligned in the proximal/distal axis. The Anatolog sensors have a sampling frequency of 100Hz. Electromyographic data recording is performed by setting up a number of EMGs depending on the healthy population or the level of amputation. Surface electromyography (sEMG) signals will be recorded from 10 muscles on each lower limb for control subjects and transtibial amputees; Other: Physiological; Energy consumption (VO2), will be performed using the VO2 Master Pro (VO2 Master Health Sensors Inc., Vernon, British Columbia, CA). Each participant will wear a face mask connected to the VO2 Master, which will measure oxygen consumption in real time during the assessment. The mask will be adjusted to prevent air leakage and ensure accurate measurements.; Other: Proprioceptive; For amputees, the joint above the amputation will be measured due to the presence of the proximal insertions of the bi-articular muscles and the absence of their distal insertion (i.e., knee joint for transtibial amputees and hip joint for transfemoral amputees).
Transtibial amputee patients	Other: Biomechanics; Amputees and controls will be equipped with measurement sensors to record spatio-temporal, kinetic, kinematic, pressure, electromyographic and physiological parameters of gait in the movement analysis laboratory (GRAIL System). 16 Anatolog FSR sensors will be installed in the amputee population (transtibial, transfemoral on the medial, lateral, anterior and posterior parts of the stump, 4 per side, aligned in the proximal/distal axis. The Anatolog sensors have a sampling frequency of 100Hz. Electromyographic data recording is performed by setting up a number of EMGs depending on the healthy population or the level of amputation. Surface electromyography (sEMG) signals will be recorded from 10 muscles on each lower limb for control subjects and transtibial amputees; Other: Physiological; Energy consumption (VO2), will be performed using the VO2 Master Pro (VO2 Master Health Sensors Inc., Vernon, British Columbia, CA). Each participant will wear a face mask connected to the VO2 Master, which will measure oxygen consumption in real time during the assessment. The mask will be adjusted to prevent air leakage and ensure accurate measurements.; Other: Proprioceptive; For amputees, the joint above the amputation will be measured due to the presence of the proximal insertions of the bi-articular muscles and the absence of their distal insertion (i.e., knee joint for transtibial amputees and hip joint for transfemoral amputees).
Transfemoral amputee patients	Other: Biomechanics; Amputees and controls will be equipped with measurement sensors to record spatio-temporal, kinetic, kinematic, pressure, electromyographic and physiological parameters of gait in the movement analysis laboratory (GRAIL System). 16 Anatolog FSR sensors will be installed in the amputee population (transtibial, transfemoral on the medial, lateral, anterior and posterior parts of the stump, 4 per side, aligned in the proximal/distal axis. The Anatolog sensors have a sampling frequency of 100Hz. Electromyographic data recording is performed by setting up a number of EMGs depending on the healthy population or the level of amputation. Surface electromyography (sEMG) signals will be recorded from 10 muscles on each lower limb for control subjects and transtibial amputees; Other: Physiological; Energy consumption (VO2), will be performed using the VO2 Master Pro (VO2 Master Health Sensors Inc., Vernon, British Columbia, CA). Each participant will wear a face mask connected to the VO2 Master, which will measure oxygen consumption in real time during the assessment. The mask will be adjusted to prevent air leakage and ensure accurate measurements.; Other: Proprioceptive; For amputees, the joint above the amputation will be measured due to the presence of the proximal insertions of the bi-articular muscles and the absence of their distal insertion (i.e., knee joint for transtibial amputees and hip joint for transfemoral amputees).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Locomotor adaptations induced by amputations on inter-segmental coordination by the evaluation of continuous relative phases under different walking conditions	MARP (Mean Absolute Relative Phase) index of Continuous Relative Phases (movement analysis) where MARP = 0 indicates perfectly synchronization in both segments throughout the gait cycle and elevated MARP indicates poor coordination between the segments	Day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Locomotor adaptations induced by amputations on the impact of locomotor constraints such as inclinations on the explanation of muscular synergies under different walking conditions	Muscle synergy explanation index	Day 0
Locomotor adaptations induced by amputations on the extent of locomotor constraints such as inclinations on the explanation of muscular synergies under different walking conditions	Number of muscle synergies	Day 0
Locomotor adaptations induced by amputations on the variability of pressure distributions in the socket under different walking conditions	Variability of pressures in the socket measured with high-pressure Force-Sensing Resistor sensor. The variability will be determined according to the standard deviation of all 16 pressures measured during a walking cycle.	Day 0
Locomotor adaptations induced by amputations on oxygen consumption under different walking conditions	Average VO2 in the final 30 seconds of walking (mL/mn/kg)	Day 0
Locomotor adaptations induced by amputations on energy consumption under different walking conditions	Cost of the task defined by the difference in O2 consumption during walking compared to O2 consumption at rest.	Day 0
Locomotor adaptations induced by amputations on heart rate under different walking conditions	Beats per minute	Day 0
Characterize the proprioceptive deficits induced by amputations on the angular precision of the joints	Reduction of the angular matching error, where the unilateral angular positioning error is measured as the difference in angular data between the reference angle and the estimated angle	Day 0
Characterize the proprioceptive deficits induced by amputations on movement perception	Angular displacement detection threshold (°)	Day 0
Characterize the proprioceptive deficits induced by amputations on response time	Response time for angular matching (ms)	Day 0
Characterize the proprioceptive deficits induced by amputations on angular displacement	Angular displacement direction detection (%)	Day 0
Identify a method for restoring proprioceptive deficits via modulation of the "optimal" frequency and amplitude	Proprioception index (average of the different errors and detection thresholds)	Day 0

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nīmes
• Investigators: Principal Investigator: Eric Pantera, CHU de Nîmes

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: January 13, 2025
• First Submitted That Met QC Criteria: January 13, 2025
• First Posted (Actual): January 17, 2025

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 10, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mechanical Phenomena; Physical Phenomena; Biophysical Phenomena; Biomechanical Phenomena
• Other Study ID Numbers: LOCAL/2024/EP-02

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No