Intelligent Rehabilitation and Engineering Open Access

Intelligent Rehabilitation and Engineering: Empowering the People with Disabilities

Relationship between Pushing Force and Improvement in Total Active Motion in Training with Finger Extensor Facilitation Training Device “iPARKO-2”

The recovery of hand function in chronic stroke survivors is challenging because of finger complexity and post-stroke spasticity. This study developed iPARKO-2, a novel device that simulates the manual finger extensor facilitation technique while overcoming the limitations of the original device. iPARKO-2 enables the simultaneous fixation of the index through the little fingers and applies resistance from the proximal phalanges, allowing training in patients with strong fingertip spasticity. This study is a pilot study aimed at technical validation and feasibility. Five participants underwent training at three distinct target-pushing force levels. Concurrently, their active range of motion and extensor muscle activity were measured. The results show a direct correlation between the increased pushing force and the improvement in total active motion. Furthermore, the level of muscle activity exhibited a positive correlation with the extent of the observed improvement. iPARKO-2 also reduced the fixation time and enhanced usability. These findings suggest that iPARKO-2 effectively enhances voluntary hand movements and that pushing force is a key factor in determining training efficacy.

Advances and Trends in Intelligent Lower-Limb Prostheses: A Systematic Review of Mechanical Design, Sensing, and Control

Intelligent lower-limb prostheses are evolving from single-joint assistance toward coordinated, system-level control that supports cross-task adaptation, multimodal intent estimation, and verifiable safety. This systematic review surveys powered, semi-active, microprocessor-controlled, and related intelligent lower-limb prosthesis literature published between 1 January 2021 and 1 January 2026, spanning electromechanical design, sensing and human-machine interfaces, state/phase estimation, intent/terrain recognition, control and learning, evaluation endpoints, and translational considerations. Following a PRISMA-style workflow, 180 full-text reports were included and synthesized into a modular taxonomy covering clinical needs and endpoints; actuation and transmission; sensing and human-machine interfaces; phase/state estimation; intent/terrain recognition; impedance and trajectory control, including model predictive control; personalization with explicit safety constraints; real-world validation; and safety, reliability, and standardization. Emerging patterns include backdrivable low-impedance hardware, multimodal sensing with uncertainty-aware gating, and continuous phase-variable control, although the level of validation remains heterogeneous. Key gaps remain in endpoint consistency, external validity across users and contexts, and failure-mode reporting. We recommend benchmark protocols and system-level validation frameworks to support more reproducible evaluation and future clinical translation.

Development of a Hand Spasticity Testing Device for Quantitative Wrist Spasticity Assessment and Automated Evaluation of the Modified Tardieu Scale

The Modified Tardieu Scale is commonly used to assess spasticity by differentiating between neural and mechanical resistance. However, its manual administration may reduce objectivity and reproducibility. This study aimed to automate the Quality of Muscle Reaction (QMR) assessment in the wrist flexors. To this end, we developed a Hand Spasticity Testing (HaST) device and QMR classification model. The device integrates two inertial measurement units, surface electromyography sensors, and a force sensor to record joint angle, angular velocity, muscle activity, and reaction force during passive wrist extension. A classification model was then constructed using decision trees based on the acquired features, with training and evaluation performed via leave-one-out cross-validation. Using the developed device, 19 participants with upper-limb spasticity were evaluated. Key features, such as the number of local maxima in joint angle, velocity, and reaction force, along with other derived parameters, were extracted and classified to estimate QMR grades (0–2). The proposed method achieved an overall accuracy of 76% and a weighted average F₁-score of 0.76. These results demonstrate the feasibility of objective and automated QMR quantification using the HaST device. The proposed system may serve as a preliminary screening and documentation tool to support objective spasticity assessment in clinical settings.

Relationship between Pushing Force and Improvement in Total Active Motion in Training with Finger Extensor Facilitation Training Device “iPARKO-2”

The recovery of hand function in chronic stroke survivors is challenging because of finger complexity and post-stroke spasticity. This study developed iPARKO-2, a novel device that simulates the manual finger extensor facilitation technique while overcoming the limitations of the original device. iPARKO-2 enables the simultaneous fixation of the index through the little fingers and applies resistance from the proximal phalanges, allowing training in patients with strong fingertip spasticity. This study is a pilot study aimed at technical validation and feasibility. Five participants underwent training at three distinct target-pushing force levels. Concurrently, their active range of motion and extensor muscle activity were measured. The results show a direct correlation between the increased pushing force and the improvement in total active motion. Furthermore, the level of muscle activity exhibited a positive correlation with the extent of the observed improvement. iPARKO-2 also reduced the fixation time and enhanced usability. These findings suggest that iPARKO-2 effectively enhances voluntary hand movements and that pushing force is a key factor in determining training efficacy.utf-8

Development of a Hand Spasticity Testing Device for Quantitative Wrist Spasticity Assessment and Automated Evaluation of the Modified Tardieu Scale

The Modified Tardieu Scale is commonly used to assess spasticity by differentiating between neural and mechanical resistance. However, its manual administration may reduce objectivity and reproducibility. This study aimed to automate the Quality of Muscle Reaction (QMR) assessment in the wrist flexors. To this end, we developed a Hand Spasticity Testing (HaST) device and QMR classification model. The device integrates two inertial measurement units, surface electromyography sensors, and a force sensor to record joint angle, angular velocity, muscle activity, and reaction force during passive wrist extension. A classification model was then constructed using decision trees based on the acquired features, with training and evaluation performed via leave-one-out cross-validation. Using the developed device, 19 participants with upper-limb spasticity were evaluated. Key features, such as the number of local maxima in joint angle, velocity, and reaction force, along with other derived parameters, were extracted and classified to estimate QMR grades (0–2). The proposed method achieved an overall accuracy of 76% and a weighted average F₁-score of 0.76. These results demonstrate the feasibility of objective and automated QMR quantification using the HaST device. The proposed system may serve as a preliminary screening and documentation tool to support objective spasticity assessment in clinical settings.utf-8

Advances and Trends in Intelligent Lower-Limb Prostheses: A Systematic Review of Mechanical Design, Sensing, and Control

Intelligent lower-limb prostheses are evolving from single-joint assistance toward coordinated, system-level control that supports cross-task adaptation, multimodal intent estimation, and verifiable safety. This systematic review surveys powered, semi-active, microprocessor-controlled, and related intelligent lower-limb prosthesis literature published between 1 January 2021 and 1 January 2026, spanning electromechanical design, sensing and human-machine interfaces, state/phase estimation, intent/terrain recognition, control and learning, evaluation endpoints, and translational considerations. Following a PRISMA-style workflow, 180 full-text reports were included and synthesized into a modular taxonomy covering clinical needs and endpoints; actuation and transmission; sensing and human-machine interfaces; phase/state estimation; intent/terrain recognition; impedance and trajectory control, including model predictive control; personalization with explicit safety constraints; real-world validation; and safety, reliability, and standardization. Emerging patterns include backdrivable low-impedance hardware, multimodal sensing with uncertainty-aware gating, and continuous phase-variable control, although the level of validation remains heterogeneous. Key gaps remain in endpoint consistency, external validity across users and contexts, and failure-mode reporting. We recommend benchmark protocols and system-level validation frameworks to support more reproducible evaluation and future clinical translation.utf-8

Intelligent Rehabilitation and Engineering: Empowering the People with Disabilities