Percutaneous Ultrasound-guided Neuromodulation to Improve Gait Rehabilitation in Patients Who Have Suffered a Stroke.

The goal of this clinical trial is to learn if percutaneous ultrasound-guided neuromodulation (NMP-e) can improve gait rehabilitation in adults who have suffered a stroke. The main questions it aims to answer are: * Does NMP-e improve walking speed in stroke survivors? * Does NMP-e enhance muscle strength, functional mobility, reduce spasticity, improve balance, and increase health-related quality of life? Researchers will compare the addition of NMP-e to conventional physiotherapy versus conventional physiotherapy alone to see if the intervention provides additional benefits in gait rehabilitation and other functional outcomes. Participants will: * Continue their regular physiotherapy treatment consisting of passive and active-assisted mobilizations and strength exercises. * Receive NMP-e targeting the sciatic nerve at mid-thigh and the common peroneal nerve at the fibular head (experimental group only). * Undergo stimulation with an electrostimulator at 10 Hz for 10 seconds per trial, repeated 10 times, with intensity adjusted for comfort. * Be evaluated before the intervention, immediately after, and one week later using: * 10-Meter Walk Test for gait speed * Dynamometry for ankle plantarflexor and dorsiflexor strength * Time Up and Go test for functional mobility * Modified Modified Ashworth Scale for spasticity * Berg Balance Scale for balance * EuroQoL-5 Dimensions for health-related quality of life Participants must be adults aged 18-70, able to walk 10 meters without assistance, currently receiving physiotherapy, and able to provide informed consent. Key exclusions include pregnancy, bleeding disorders, needle allergies, systemic inflammatory disorders, or recent invasive physiotherapy. This randomized controlled trial will be conducted at ATECE, \*\*a Spanish association dedicated to the care and rehabilitation of individuals with acquired brain injury\*\*, where participants will be recruited and receive their interventions. The study aims to evaluate the potential of NMP-e as an adjunctive therapy for improving gait and related functional outcomes in subacute and chronic stroke patients.