Effectiveness of Robot-Assisted Structured Foot-Ankle Sensorimotor Training in Stroke Patients

Overview

Introduction: Stroke is a leading cause of long-term disability worldwide. Persistent lower-extremity motor and somatosensory impairments after stroke commonly limit walking and balance despite rehabilitation. Virtual reality (VR)-integrated robotic rehabilitation may support structured, goal-directed ankle-foot practice; however, there is limited evidence for ankle-foot-focused sensorimotor protocols. In particular, approaches that combine robot-assisted motor training with a plantar tactile localization task and VR-supported joint position sense (JPS) training to target plantar sensory and proprioceptive function are scarce. Therefore, this study aims to evaluate the effectiveness of a structured, VR-integrated, robot-assisted ankle-foot sensorimotor rehabilitation protocol in individuals with chronic stroke and to examine its effects on clinical and sensorimotor outcomes. Methods and analysis: This is an assessor-blinded, two-arm, parallel-group randomized controlled trial. Thirty individuals with chronic stroke will be randomized 1:1 to the Robot-assisted Training Group (RTG) or the Manual Training Group (MTG). All participants will receive conventional rehabilitation; in addition, RTG will receive a structured robot-assisted ankle-foot training program integrated with virtual reality and assist-as-needed control, whereas MTG will receive the same structured ankle-foot training protocol delivered manually by a physiotherapist. Interventions will be delivered three times per week for 6 weeks (18 sessions), and total session duration will be time-matched between groups (50-60 min per session). The primary outcome will be the change in walking speed, derived from the 10-Meter Walk Test, from baseline to 6 weeks. Secondary outcomes will include 2-Minute Walk Test distance, ankle range of motion, joint position sense, plantar tactile sensation, muscle tone, motor performance, static and dynamic balance, and stroke-specific quality of life.

Interventions

• Other Robot-Assisted Foot-Ankle Training
  Stage 1: Vibration Training Applied for Proper Stepping on the Sole of the Foot and Proper Pressure Distribution: The first step of the training will be constant vibration, and the second step will be sensory localization training with vibration. Stage 2: Passive Joint Range of Motion Training with Virtual Reality: The platform will move the ankle passively (passive stretching). Stage 3: Joint Position Sense Training: The platform will bring the patient's ankle to a certain dorsiflexion positi
• Other Conventional Foot-Ankle Training
  Stage 1: Sensory Training to the Sole of the Foot: In the first step of the training, the physiotherapist will manually apply constant pressure with a blunt object, and in the second step, sensory localization training with a blunt object will be performed. Stage 2: Passive Joint Range of Motion Training: The ankle will be manually moved passively (passive stretching) by the physiotherapist. Stage 3: Joint Position Sense Training: The physiotherapist will bring the patient's ankle to a certain d

Primary outcome measures

• Walking Speed (10-Meter Walk Test) [Time frame: From baseline to the end of the 6-week intervention]

Secondary outcome measures (11)

• Static Balance Assessment (The Single-Leg Stance Test) [Time frame: From baseline to the end of the 6-week intervention]
• Assessment of Joint Position Sense [Time frame: From baseline to the end of the 6-week intervention]
• Assessment of Satisfaction Level Related to the Robot (Quest Scale-Lıkert Scale-4's) [Time frame: From baseline to the end of the 6-week intervention]
• Quality of Life Assessment (The Stroke-Specific Quality of Life Scale) [Time frame: From baseline to the end of the 6-week intervention]
• Tactile Perception Level (The Semmes-Weinstein Monofilament Test) [Time frame: From baseline to the end of the 6-week intervention]
• Walking Capacity [Time frame: From baseline to the end of the 6-week intervention]
• Motor Performance (The Fugl-Meyer Assessment for the Lower Extremity) [Time frame: From baseline to the end of the 6-week intervention]
• Dynamic Balance Assessment 1 (TUG) [Time frame: From baseline to the end of the 6-week intervention]
• Modified Ashworth Scale (Tonus Assessment) [Time frame: From enrollment to the end of treatment at 6 week intervention]
• Assessment of Joint Range of Motion (Electrogoniometer) [Time frame: From baseline to the end of the 6-week intervention]
• Dynamic Balance Assessment 2 (The Mini Balance Evaluation Systems Test) [Time frame: From baseline to the end of the 6-week intervention]

Eligibility criteria

The inclusion criteria are as follows:

• Age 40-65 years,
• Able to understand and follow study instructions,
• Able to communicate coherently and oriented in time and place,
• Provided written informed consent,
• Stroke ≥6 months prior to enrollment (chronic stroke),
• Ankle plantarflexor spasticity ≤2 on the Modified Ashworth Scale,
• Ankle dorsiflexor strength ≥ grade 2 on the Medical Research Council (MRC) scale,
• Passive ankle dorsiflexion to neutral (90°; 0°) without a plantarflexion contracture,
• Moderate or mild lower-extremity impairment based on the Fugl-Meyer Assessment-Lower Extremity (FMA-LE) score (21-27 moderate; 28-34 mild/good),
• Able to sit for at least 1 hour,
• Able to walk at least 10 meters with or without an assistive device,
• Completed all conventional lower-extremity physical therapy and rehabilitation programs.

The exclusion criteria are as follows:

• Cognitive impairment (Mini-Mental State Test score ≤ 24),
• Conditions affecting walking or balance (e.g., orthopedic complications, lower extremity amputation, osteoporosis),
• Insufficient visual acuity to view a screen (e.g., diplopia),
• Severe visual deficits (e.g., hemianopia) or vestibular disorders34,
• Sensory deficits such as hemisensory neglect,
• Acute musculoskeletal or cardiovascular disorders,
• Intrathecal baclofen pump use or botulinum toxin injections within the past 5 months,
• Fixed or painful contracture of the paretic ankle,
• Uncontrolled systemic diseases (e.g., diabetes, hypertension, debilitating or immunosuppressive diseases),
• history of a non-stroke neurological disease/disorder that may impair comprehension of instructions,
• Concurrent participation in other lower-extremity physical therapy, robotic rehabilitation, or neurological exercise programs.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 2 centers

• İstanbul Medipol Üniversitesi-Acıbadem Medipol Region Hospital — Istanbul
• İstanbul Medipol Üniversitesi — Istanbul

Publications

• Kwong PWH, Ng SSM, Chung RCK, Ng GYF. A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors. PLoS One. 2017 Oct 19;12(10):e0185807. doi: 10.1371/journal.pone.0185807. eCollection 2017. PMID 29049293
• Kim KH, Jang SH. Effects of Cognitive Sensory Motor Training on Lower Extremity Muscle Strength and Balance in Post Stroke Patients: A Randomized Controlled Study. Clin Pract. 2021 Sep 14;11(3):640-649. doi: 10.3390/clinpract11030079. PMID 34563008
• Kim H, Cho S, Lee H. Effects of passive Bi-axial ankle stretching while walking on uneven terrains in older adults with chronic stroke. J Biomech. 2019 May 24;89:57-64. doi: 10.1016/j.jbiomech.2019.04.014. Epub 2019 Apr 17. PMID 31060809
• Khalifeloo M, Naghdi S, Ansari NN, Akbari M, Jalaie S, Jannat D, Hasson S. A study on the immediate effects of plantar vibration on balance dysfunction in patients with stroke. J Exerc Rehabil. 2018 Apr 26;14(2):259-266. doi: 10.12965/jer.1836044.022. eCollection 2018 Apr. PMID 29740561
• Kavounoudias A, Roll R, Roll JP. The plantar sole is a 'dynamometric map' for human balance control. Neuroreport. 1998 Oct 5;9(14):3247-52. doi: 10.1097/00001756-199810050-00021. PMID 9831459
• de la Iglesia DH, Mendes AS, Gonzalez GV, Jimenez-Bravo DM, de Paz Santana JF. Connected Elbow Exoskeleton System for Rehabilitation Training Based on Virtual Reality and Context-Aware. Sensors (Basel). 2020 Feb 6;20(3):858. doi: 10.3390/s20030858. PMID 32041156
• Hussain I, Jany R. Interpreting Stroke-Impaired Electromyography Patterns through Explainable Artificial Intelligence. Sensors (Basel). 2024 Feb 21;24(5):1392. doi: 10.3390/s24051392. PMID 38474928
• Hoh JE, Semrau JA. The Role of Sensory Impairments on Recovery and Rehabilitation After Stroke. Curr Neurol Neurosci Rep. 2025 Mar 6;25(1):22. doi: 10.1007/s11910-025-01407-9. PMID 40047982

Identifiers

NCT: NCT07091045 · E-10840098-202.3.02-2627

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗