Ankle Rehabilitation Research Articles

CONCEPTUAL DESIGN FOR ROBOT-AIDED ANKLE REHABILITATION DEVICE

Ankle injury is one of physical injury that can happen whether in sports or in domestic accidents. The injury can take from weeks to months to recover and requires physiotherapy treatment for effective recovery. Currently, there are established treatments for ankle rehabilitation in hospital such as endurance training and range-of-motion training. However, the success of rehabilitation for ankle injury directly depends on physiotherapy administered by experts. This conventional therapy treatment requires patients to frequently visit to hospital which is tedious and costly. To solve this, researchers have introduced a number of robot-aided ankle rehabilitation devices which has been developed in the last decade. However, those devices are bulky and do not designed for portability and configurability – which is an important feature for patients undergoing rehabilitation at home. In this paper, we proposed a concept based on robot-aided ankle rehabilitation device to assist patients undergo rehabilitation procedures. We focused on all patients’ need especially based on important features such as portability and configurability of the device. Standard design process were followed including concept generation and concept selection according to all relevant criteria using Morphological Charts and Pugh Method. A Pulley Driven Cable Based Parallel Mechanism robot-aided ankle rehabilitation device has been selected based on selections from 5 different concept design generated. We show that a design based on parallel mechanisms should provide the needed portability and configurability. This result provides an insight for a portable and configurable robot-aided ankle rehabilitation device.

A Novel Approach of Using SMA Wires Actuated Stewart Platform for Continuous Passive Motion (CPM) of Ankle Rehabilitation Therapy

This paper analyses the result of the ongoing experimental research on the operational behavior of SMA in medical and robotics application. SMA are the materials that have the ability to return their original shape when subjected to the appropriate thermo mechanical interaction. SMA finds very wide applications in various facets of robotic equipments and industrial automation. They are easy to manufacture, low cost and can be integrated with human operations without any large scale safety requirements. Three SMA wires with diameters of 0.254 mm, 0.381 mm and 0.508 mm were experimented to measure the displacement of the wire with various bias forces. The 0.25 mm wire is best suited for generating substantial displacement. The displacement may be used to create CPM (Continues Passive Motion) for the Stewart platform for ankle rehabilitation therapy.

Three-Stage Design Analysis and Multicriteria Optimization of a Parallel Ankle Rehabilitation Robot Using Genetic Algorithm

This paper describes the design analysis and optimization of a novel 3-degrees of freedom (DOF) wearable parallel robot developed for ankle rehabilitation treatments. To address the challenges arising from the use of a parallel mechanism, flexible actuators, and the constraints imposed by the ankle rehabilitation treatment, a complete robot design analysis is performed. Three design stages of the robot, namely, kinematic design, actuation design, and structural design are identified and investigated, and, in the process, six important performance objectives are identified which are vital to achieve design goals. Initially, the optimization is performed by considering only a single objective. Further analysis revealed that some of these objectives are conflicting, and hence these are required to be simultaneously optimized. To investigate a further improvement in the optimal values of design objectives, a preference-based approach and evolutionary-algorithm-based nondominated sorting algorithm (NSGA II) are adapted to the present design optimization problem. Results from NSGA II are compared with the results obtained from the single objective optimization and preference-based optimization approaches. It is found that NSGA II is able to provide better design solutions and is adequate to optimize all of the objective functions concurrently. Finally, a fuzzy-based ranking method has been devised and implemented in order to select the final design solution from the set of nondominated solutions obtained through NSGA II. The proposed design analysis of parallel robots together with the multiobjective optimization and subsequent fuzzy-based ranking can be generalized with modest efforts for the development of all of the classes of parallel robots.

Ankle rehabilitation device with two degrees of freedom and compliant joint

We propose a rehabilitation device that we intend to be low cost and easy to manufacture. The system will ensure functionality but also have a small dimensions and low mass, considering the physiological dimensions of the foot and lower leg. To avoid injure of the ankle joint, this device is equipped with a compliant joint between the motor and mechanical transmission. The torque of this joint is intended to be adjustable, according to the degree of ankle joint damage. To choose the material and the dimensions of this compliant joint, in this paper we perform the first stress simulation. The minimum torque is calculated, while the maximum torque is given by the preliminary chosen actuator.

Development of Stewart platform type ankle-foot device for trip prevention support.

This paper presents an ankle-foot device using a Stewart platform, which is a type of parallel-link mechanism, for trip prevention support. The developed device can reproduce the input motions of the ankle joint in six degrees of freedom by controlling six pneumatic cylinders at the same time. The root mean square errors of the 3-D position and rotation angle of the reproduced motions with the input motions (dorsiflexion and plantar flexion) were 6.3 mm and 3.0°, respectively. Verification experiments for trip prevention support performance were conducted by comparing motions in each walking condition measured using a motion capture system. The experimental results showed that the minimum foot clearance during mid-swing and initial swing increased significantly by the trip prevention support offered by the developed device. The developed device can perform passive exercises for ankle rehabilitation and support walking for trip prevention.

Evaluation of venous return in lower limb by passive ankle exercise performed by PHARAD.

This paper presents evaluation of venous return, i.e., blood flow volume of vein (BF), in the lower limb after passive exercise performed by our developed "parallel link type human ankle rehabilitation assistive device (PHARAD)". The PHARAD can perform complex passive exercises (plantar flexion/dorsiflexion, inversion/eversion, adduction/abduction, and combination of these motions) by reproducing input motions of a foot plate that is attached to a sole of foot. The passive exercise can be performed for not only rehabilitation but also prevention of deep vein thrombosis (DVT). In this study, we measured the concentration of Total hemoglobin (Total-Hb) using multi-channel near infra-red spectroscopy (NIRS)-based tissue oximeters and calculated a gradient of Total-Hb during a venous occlusion. We defined the gradient as BF and evaluated BF after 3 min passive exercise performed by the PHARAD comparing to BF of resting. Seven healthy young adult people were recruited for the experiment and we assessed passive exercise, active exercise, and walking. Experimental results show that BF after the passive exercises significantly increases compare to BF of resting and this indicates that passive exercises performed by the PHARAD increases BF and has a potential to prevent DVT.

Multi-objective optimization of a parallel ankle rehabilitation robot using modified differential evolution algorithm

Dimensional synthesis is one of the most difficult issues in the field of parallel robots with actuation redundancy. To deal with the optimal design of a redundantly actuated parallel robot used for ankle rehabilitation, a methodology of dimensional synthesis based on multi-objective optimization is presented. First, the dimensional synthesis of the redundant parallel robot is formulated as a nonlinear constrained multi-objective optimization problem. Then four objective functions, separately reflecting occupied space, input/output transmission and torque performances, and multi-criteria constraints, such as dimension, interference and kinematics, are defined. In consideration of the passive exercise of plantar/dorsiflexion requiring large output moment, a torque index is proposed. To cope with the actuation redundancy of the parallel robot, a new output transmission index is defined as well. The multi-objective optimization problem is solved by using a modified Differential Evolution(DE) algorithm, which is characterized by new selection and mutation strategies. Meanwhile, a special penalty method is presented to tackle the multi-criteria constraints. Finally, numerical experiments for different optimization algorithms are implemented. The computation results show that the proposed indices of output transmission and torque, and constraint handling are effective for the redundant parallel robot; the modified DE algorithm is superior to the other tested algorithms, in terms of the ability of global search and the number of non-dominated solutions. The proposed methodology of multi-objective optimization can be also applied to the dimensional synthesis of other redundantly actuated parallel robots only with rotational movements.

A review on the mechanical design elements of ankle rehabilitation robot

Ankle rehabilitation robots are developed to enhance ankle strength, flexibility and proprioception after injury and to promote motor learning and ankle plasticity in patients with drop foot. This article reviews the design elements that have been incorporated into the existing robots, for example, backdrivability, safety measures and type of actuation. It also discusses numerous challenges faced by engineers in designing this robot, including robot stability and its dynamic characteristics, universal evaluation criteria to assess end-user comfort, safety and training performance and the scientific basis on the optimal rehabilitation strategies to improve ankle condition. This article can serve as a reference to design robot with better stability and dynamic characteristics and good safety measures against internal and external events. It can also serve as a guideline for the engineers to report their designs and findings.

Improving Chronic Ankle Instability Patient Reported Outcomes with Sensory-Targeted Ankle Rehabilitation Strategies

Improving Chronic Ankle Instability Patient Reported Outcomes with Sensory-Targeted Ankle Rehabilitation Strategies

A 3-PRS parallel manipulator for ankle rehabilitation: towards a low-cost robotic rehabilitation

SUMMARYThis paper presents the design, kinematics, dynamics and control of a low-cost parallel rehabilitation robot developed at the Universitat Politècnica de Valencia. Several position and force controllers have been tested to ensure accurate tracking performances. An orthopedic boot, equipped with a force sensor, has been placed over the platform of the parallel robot to perform exercises for injured ankles. Passive, active-assistive and active-resistive exercises have been implemented to train dorsi/plantar flexion, inversion and eversion ankle movements. In order to implement the controllers, the component-based middleware Orocos has been used with the advantage over other solutions that the whole scheme control can be implemented modularly. These modules are independent and can be configured and reconfigured in both configuration and runtime. This means that no specific knowledge is needed by medical staff, for example, to carry out rehabilitation exercises using this low-cost parallel robot. The integration between Orocos and ROS, with a CAD model displaying the actual position of the rehabilitation robot in real time, makes it possible to develop a teleoperation application. In addition, a teleoperated rehabilitation exercise can be performed by a specialist using a Wiimote (or any other Bluetooth device).

Robot-Aided Neurorehabilitation: A Pediatric Robot for Ankle Rehabilitation.

This paper presents the pediAnklebot, an impedance-controlled low-friction, backdriveable robotic device developed at the Massachusetts Institute of Technology that trains the ankle of neurologically impaired children of ages 6-10 years old. The design attempts to overcome the known limitations of the lower extremity robotics and the unknown difficulties of what constitutes an appropriate therapeutic interaction with children. The robot's pilot clinical evaluation is on-going and it incorporates our recent findings on the ankle sensorimotor control in neurologically intact subjects, namely the speed-accuracy tradeoff, the deviation from an ideally smooth ankle trajectory, and the reaction time. We used these concepts to develop the kinematic and kinetic performance metrics that guided the ankle therapy in a similar fashion that we have done for our upper extremity devices. Here we report on the use of the device in at least nine training sessions for three neurologically impaired children. Results demonstrated a statistically significant improvement in the performance metrics assessing explicit and implicit motor learning. Based on these initial results, we are confident that the device will become an effective tool that harnesses plasticity to guide habilitation during childhood.

Abstract W MP57: Effects of Wearable Robotic Training of Ankle and Mobility Rehabilitation in Acute Stroke

Background and Purpose: Stroke is the fourth leading cause of death in the US and is a leading cause of adult disability. It was reported that the first few months post stroke is critical in neural plasticity and motor recovery. Presently, effective treatment options for ankle impairment and mobility are limited, especially for in-bed acute stroke rehabilitation. In this study, wearable robotic training involving passive stretching and active movement training was investigated to determine its efficacy in improving stroke outcome. Methods: Eleven patients with acute stroke participated. This was completed in a clinical in-patient setting (45 min/session, 3~5х/week, total 18 session). Participants were aged 53.7±17.4 (mean±SD); robotic treatment was given averaged 40.5 days of stroke onset. They continued receiving standard inpatient physical therapy during the study. One way repeated measures ANOVA was used to compare clinical and biomechanical outcome measures across the repeated measures. Results: Preliminary results showed an improvement after the multiple sessions of training with F-M in LE increased from 14.8 ± 8.8 and 19.4 ± 8.2 (p<.01), STREAM score in LE from 32.1±21.4 to 47.9±30.1 (p=.02), the BBS increased from 35.2±17.8 to 38.0±18.2. Ankle active range of motion (AROM) in dorsiflexion increased from -5.7 ± 7.2° to 2.3 ± 8.1°(p=.004), ankle passive ROM in dorsiflexion from 14.0 ± 7.1° to 19.9 ± 5.3° (p=.002). Dorsiflexor strength increased from 0 ± 2.2 N m before training to 2.4 ±3.5 N m after training (p=.003). Plantarflexor strength increased from 6.7±9.9 Nm, to 12.6 ± 11.4 Nm (p=.004). Other measures showed no significant improvements, such as 6MWT increased from 302.0 ± 416.4 and 540.6 ± 563.4 feet, the MAS of ankle was 2.2 ± 1.1 to 1.6 ± 1.2. Conclusions: The use of robotic device demonstrated improvements in selected outcome measures in hospital settings, and it was efficiently administer in the clinic. The results suggest that impaired lower limbs of acute stroke can respond to controlled stretching and movement training in terms of muscle biomechanical properties and improve lower extremity functional activities in acute rehabilitation.The limitation of this study was its small sample size and lack of a control group.

Neuromuscular control and rehabilitation of the unstable ankle.

Lateral ankle sprain is a common orthopedic injury with a very high recurrence rate in athletes. After decades of research, it is still unclear what contributes to the high recurrence rate of ankle sprain, and what is the most effective intervention to reduce the incident of initial and recurrent injuries. In addition, clinicians often implement balance training as part of the rehabilitation protocol in hopes of enhancing the neuromuscular control and proprioception of the ankle joint. However, there is no consensus on whether the neuromuscular control and proprioception are compromised in unstable ankles. To reduce the prevalence of ankle sprains, the effectiveness of engaging balance training to enhance the neuromuscular control and proprioception of the ankle joint is also questionable.

1P2-H08 足関節リハビリ動作に伴う脳波(EEG)変化の解析

1P2-H08 足関節リハビリ動作に伴う脳波(EEG)変化の解析

S1110203 生体信号を元にした下肢リハビリ支援機器の開発における運動準備電位の違い

In recent years, the Japanese population has been aging rapidly. People with lifestyle-related disease have been increasing too. It is highly probable that elderly people will develop a stroke related to lifestyle related disease, which can cause muscle contracture. Patients and elderly people can have muscle contracture and paralysis caused by stroke. It is important to restrict nerve structure for functional recovery. We aim to construct Brain computer Interface (BCI) system by moving ankle joint rehabilitation support device in EEG of voluntary movement. Therefore we measured readiness potential (RP) as EEG. The movements that we measured are plantar flexion and dorsal flexion of the ankle, bending movement of the arm, vertical motion of the finger. We consider difference in RP.

1A1-O10 スチュワートプラットフォーム型短下肢装具によるつまずき防止支援に関する研究

This paper presents the ankle-foot orthosis using Stewart platform for trip prevention support. The developed orthosis can reproduce the input motions of the ankle joint in six degrees of freedom. We conducted performance verification experiments of the developed orthosis. Verification experiments of motion reproducibility were implemented by comparing the reproduced motions with the input motions. The experimental results showed that the root mean square error values of the 3D position and rotation angle were 6.5 mm and 2.8°, respectively. Verification experiments of the walking support performance were implemented by comparing motions in each walking condition were measured using motion capture system. The experimental results showed that Angular Displacement of right foot joint while Mid Swing and Initial Swing significantly increased by the walking support with the developed orthosis. The orthosis can conduct passive exercises for ankle rehabilitation and support walking for trip prevention.

Design and development of a parallel robot based on an XY table for ankle rehabilitation

The continuous passive motion (CPM) machines are used in the rehabilitation of members that have been injured to recover their range of motion and prevent stiffness. Nowadays, some CPM machines for knee, ankle, arm and elbow are available commercially. In this paper, a novel design of a parallel robot based on an XY table for ankle rehabilitation, that provides dorsiflexion-plantarflexion and abduction-adduction movements, is presented. Some results are presented in order to show the performance of the parallel robot for ankle rehabilitation. Proportional-derivative (PD), proportional-integral-derivative (PID) and generalised proportional integral (GPI) controllers for trajectory tracking are implemented in the virtual and physical prototype.

Novel Decoupled Parallel Mechanism for Ankle Rehabilitation and Its Optimization

Novel Decoupled Parallel Mechanism for Ankle Rehabilitation and Its Optimization

A Robot-Driven Computational Model for Estimating Passive Ankle Torque With Subject-Specific Adaptation.

Robot-assisted ankle assessment could potentially be conducted using sensor-based and model-based methods. Existing ankle rehabilitation robots usually use torquemeters and multiaxis load cells for measuring joint dynamics. These measurements are accurate, but the contribution as a result of muscles and ligaments is not taken into account. Some computational ankle models have been developed to evaluate ligament strain and joint torque. These models do not include muscles and, thus, are not suitable for an overall ankle assessment in robot-assisted therapy. This study proposed a computational ankle model for use in robot-assisted therapy with three rotational degrees of freedom, 12 muscles, and seven ligaments. This model is driven by robotics, uses three independent position variables as inputs, and outputs an overall ankle assessment. Subject-specific adaptations by geometric and strength scaling were also made to allow for a universal model. This model was evaluated using published results and experimental data from 11 participants. Results show a high accuracy in the evaluation of ligament neutral length and passive joint torque. The subject-specific adaptation performance is high, with each normalized root-mean-square deviation value less than 10%. This model could be used for ankle assessment, especially in evaluating passive ankle torque, for a specific individual. The characteristic that is unique to this model is the use of three independent position variables that can be measured in real time as inputs, which makes it advantageous over other models when combined with robot-assisted therapy.

A Novel Hybrid Rehabilitation Device for Neuromuscular Control Exercise and Rehabilitation Training

W-vibe neuromuscular control ankle rehabilitation device is designed based on the principle of a single leg stance activity. It aims to enhance the balancing level of the individuals and re-establishing neuromuscular control for ankle injuries. This type of training may also be useful for preventing injuries in people with “healthy” ankles. Single leg stance is very importance in preventing and rehabilitation for healthy, re-injury and injured ankle. For high performance sports, it needs to be carried out at the early stage to avoid injury. Most games needs players with high balancing level for example soccer, rugby, gymnastic, tennis, boxing etc. W-vibe neuromuscular control ankle technology device needs the respondent to maintain balance-that is, to attempt to make all balance correction using the dynamic ankle joint stabilizers only, while repositioning the arms, hips and knees as little as possible. Therefore the goal of this project is to develop a compact, simple structure and efficient rehabilitation device for ankle sprain patient to train both exercise and rehabilitation training for neuromuscular control. This w-vibe neuromuscular control ankle rehabilitation device analysis was using Finite Element analysis (FE) to test the safety and reliability of the device. The result shows that this tool is safe for further application.