Muscle-tendon Interaction in the Spastic Sural Triceps During Gait

Inclusion Criteria : Post-Stroke Population: * Adult male or female * Patient who had a stroke more than 7 days ago * Patient hospitalized (in conventional hospitalization or day hospital) in the university neurological rehabilitation department of CHU de Nantes * Patient with voluntary motor function graded between 2 and 4 on the MRC (Medical Research Council) scale at the GM level * Patient classified between 3 and 8 on the New Functional Ambulation Classification Post-Spinal Cord Injury Population: * Adult male or female * Patient with an incomplete spinal cord injury classified as ASIA AIS C or D from level C2 to L5 * Patient hospitalized (in conventional hospitalization or day hospital) in the neurological rehabilitation department of CHU de Nantes * Patient with voluntary motor function graded between 2 and 4 on the MRC (Medical Research Council) scale at the GM level * Patient classified between 3 and 8 on the New Functional Ambulation Classification Healthy Population: • Adult male or female without any neurological disorders Exclusion Criteria : Post-Stroke and Post-Spinal Cord Injury Population: * Minor patient * History of calf surgery, surgery to reduce triceps surae spasticity, or intramuscular injection (e.g., botulinum toxin) in the plantar flexors within the last 6 months * Patient with a progressive condition contraindicating physical exertion (e.g., syrinx, cardiovascular instability) * Peripheral pathology of the considered lower limb Healthy Popu…