Gait training with the newly developed 'LokoHelp'-system is feasible for non-ambulatory patients after stroke, spinal cord and brain injury. A feasibility study

Improving Spasticity by Using Botulin Toxin: An Overview Focusing on Combined Approaches

Spasticity is a very common sign in the neurological field. It can be defined as "a motor disorder marked by a velocity-dependent increase in muscle tone or tonic stretch reflexes" associated with hypertonia. It leads to a high risk of limb deformities and pain that prejudices residual motor function, impairing quality of life". The treatment of spasticity depends on its severity and its location and, in general, it is based on rehabilitation, oral therapies (the gamma-aminobutyric acid b agonist baclofen) and injectable medications (i.e., botulin toxins, acting on polysynaptic reflex mechanisms). The botulin toxin type A (BoNT-A) injection has been effectively used to improve different types of spasticity. However, when BoNT-A is not sufficient, a combination of nonpharmacological approaches could be attempted. Therefore, additional intervention, such as conventional physical therapy by itself or further combined with robotic gait training, may be needed. Indeed, it has been shown that combination of BoNT-A and robotics has a positive effect on activity level and upper limb function in patients with stroke, including those in the chronic phase. The aim of this review is to evaluate the efficacy of pharmacological or nonpharmacological treatment in combination with BoNT-A injections on spasticity. The combined therapy of BoNT with conventional or adjunct activities or robot-assisted training, especially with end-effectors, is a valid tool to improve patients' performance and outcomes. The combined strategies might rise the toxin's effect, lowering its dosages of botulinum and reducing side effects and costs.

Research of intent recognition in rehabilitation robots: a systematic review

PURPOSE

Rehabilitation robots with intent recognition are helping people with dysfunction to enjoy better lives. Many rehabilitation robots with intent recognition have been developed by academic institutions and commercial companies. However, there is no systematic summary about the application of intent recognition in the field of rehabilitation robots. Therefore, the purpose of this paper is to summarize the application of intent recognition in rehabilitation robots, analyze the current status of their research, and provide cutting-edge research directions for colleagues.

MATERIALS AND METHODS

Literature searches were conducted on Web of Science, IEEE Xplore, ScienceDirect, SpringerLink, and Medline. Search terms included "rehabilitation robot", "intent recognition", "exoskeleton", "prosthesis", "surface electromyography (sEMG)" and "electroencephalogram (EEG)". References listed in relevant literature were further screened according to inclusion and exclusion criteria.

RESULTS

In this field, most studies have recognized movement intent by kinematic, sEMG, and EEG signals. However, in practical studies, the development of intent recognition in rehabilitation robots is limited by the hysteresis of kinematic signals and the weak anti-interference ability of sEMG and EEG signals.

CONCLUSIONS

Intent recognition has achieved a lot in the field of rehabilitation robotics but the key factors limiting its development are still timeliness and accuracy. In the future, intent recognition strategy with multi-sensor information fusion may be a good solution.

A Multistage Hemiplegic Lower-Limb Rehabilitation Robot: Design and Gait Trajectory Planning

Most lower limb rehabilitation robots are limited to specific training postures to adapt to stroke patients in multiple stages of recovery. In addition, there is a lack of attention to the switching functions of the training side, including left, right, and bilateral, which enables patients with hemiplegia to rehabilitate with a single device. This article presents an exoskeleton robot named the multistage hemiplegic lower-limb rehabilitation robot, which has been designed to do rehabilitation in multiple training postures and training sides. The mechanism consisting of the thigh, calf, and foot is introduced. Additionally, the design of the multi-mode limit of the hip, knee, and ankle joints supports delivering therapy in any posture and training sides to aid patients with hemiplegia in all stages of recovery. The gait trajectory is planned by extracting the gait motion trajectory model collected by the motion capture device. In addition, a control system for the training module based on adaptive iterative learning has been simulated, and its high-precision tracking performance has been verified. The gait trajectory experiment is carried out, and the results verify that the trajectory tracking performance of the robot has good performance.

Research on a New Rehabilitation Robot for Balance Disorders

The treatment of patients with balance disorders is an urgent problem to be solved by the medical community. The causes of balance disorders are diverse. An aging population, traffic accidents, stroke, genetic diseases and so on are all possible factors. It has brought great pain and inconvenience to patients and their families. At present, there are two main types of assisted rehabilitation training robots for patients with balance disorders: exoskeleton robots and end robots. The exoskeleton robot is generally installed on the outside of the patient's body to follow their movement, which can support the weight of the body and provide power support to help the patient train and recover lower limb ability. The use of end robots is usually to secure the patient's foot to the motion platform and control the pedal to drive the lower limbs to conduct gait training. Such passive training is more suitable for patients with severe disorders. The patient has low awareness of active participation. This paper focuses on research on end rehabilitation training robots for balance disorders. In this paper, a robotic system for rehabilitation training of patients with balance disorders is invented. The robot body is a 9 degree of freedom (DOF) redundant series-parallel hybrid motion platform. Two sets of motion platforms with symmetrical mirror images are used together to simulate different motion modes of the human body and drive the human body to move. Each set of motion platforms is composed of a 6-DOF vestibular parallel device and a 3-DOF proprioception parallel device. It has the advantages of DOF decoupling and fast response, proposing a new structural form for the design of proprioceptive and vestibular simulation platforms. The robot's functional level can be divided into a vestibular sense module and a proprioception module according to the structure. The two modules can work independently to achieve different functions or work together to achieve complex motion and multisensory fusion. This robot is a redundant mechanism device with 9 DOFs. Through a reasonable distribution of DOF and motion, the robot's working space can be increased, and the robot's flexibility and motion performance can be improved. In this paper, a trajectory tracking control algorithm for vestibular and proprioceptive simulation is proposed, which can provide unlimited body sense training for patients within the robot's limited motion range.

Effects of end-effector robot-assisted gait training on gait ability, muscle strength, and balance in patients with spinal cord injury

BACKGROUND

There is no randomized controlled study about the effects of end-effector robot-assisted gait training (RAGT) in patients with spinal cord injury (SCI).

OBJECTIVE

To examine the effects of end-effector RAGT on gait and balance abilities in SCI.

METHODS

Thirty-one patients were randomly assigned to the RAGT (Morning Walk®, Curexo, Seoul, South Korea) or conventional therapy (CT) group. Patients were assessed using the 10-meter walk test (10MWT), 6-minute walk test (6mWT), lower extremity motor score (LEMS) and proprioception, Berg Balance Scale (BBS), Walking Index for Spinal Cord Injury-II (WISCI-II), and mobility category of Spinal Cord Independence Measure-III.

RESULTS

All clinical outcome measures significantly improved in both groups. The BBS and WISCI-II were significantly improved in the RAGT group compared to the CT group. In the RAGT group, pre-LEMS and pre-WISCI-II of the 10MWT improved group and pre-BBS of the 6mWT improved group were higher than those of the 10MWT non-improved and 6mWT non-improved group, respectively.

CONCLUSION

End-effector RAGT and CT in patients with incomplete SCI could lead to improvements in gait ability, lower extremity muscle strength, balance, proprioception, and mobility. Additionally, end-effector RAGT could improve balance and gait abilities substantially better than CT.

[Implementation of robotic mechanotherapy for movement recovery in patients after stroke]

Lower extremity dysfunction after a stroke can vary from mild to extremely severe and significantly reduce the functional independence of patients. The restoration of walking is one of the key components of rehabilitation, it requires a balanced approach and the participation of a multidisciplinary team. In the last decade, new rehabilitation methods have appeared that meet high safety standards and have a minimum set of contraindications. One of the promising methods is robotic mechanotherapy. The article presents an overview of modern technologies of robotic mechanotherapy, its types and recommendations for use in medical rehabilitation.

A Systematic Review of the Scientific Literature for Rehabilitation/Habilitation Among Individuals With Pediatric-Onset Spinal Cord Injury

Objectives

To conduct a systematic review to examine the scientific literature for rehabilitation/habilitation among individuals with pediatric-onset spinal cord injury (SCI).

Methods

A literature search of multiple databases (i.e., PubMed/MEDLINE, CINAHL, EMBASE, PsychINFO) was conducted and was filtered to include studies involving humans, published as full-length articles up to December 2020, and in English. Included studies met the following inclusion criteria: (1) ≥50% of the study sample had experienced a traumatic, acquired, nonprogressive spinal cord injury (SCI) or a nontraumatic, acquired, noncongenital SCI; (2) SCI onset occurred at ≤21 years of age; and (3) sample was assessed for a rehabilitation/habilitation-related topic. Studies were assigned a level of evidence using an adapted Sackett scale modified down to five levels. Data extracted from each study included author(s), year of publication, country of origin, study design, subject characteristics, rehabilitation/habilitation topic area, intervention (if applicable), and outcome measures.

Results

One hundred seventy-six studies were included for review (1974-2020) with the majority originating from the United States (81.3%). Most studies were noninterventional observational studies (n = 100; 56.8%) or noninterventional case report studies (n = 5; 2.8%). Sample sizes ranged from 1 to 3172 with a median of 26 (interquartile range [IQR], 116.5). Rehabilitation/habilitation topics were categorized by the International Classification of Functioning, Disability and Health (ICF); most studies evaluated ICF Body Function. There were 69 unique clinical health outcome measures reported.

Conclusion

The evidence for rehabilitation/habilitation of pediatric-onset SCI is extremely limited; nearly all studies (98%) are level 4-5 evidence. Future studies across several domains should be conducted with novel approaches to research design to alleviate issues related to sample sizes and heterogeneity.

Development of a Control System and Functional Validation of a Parallel Robot for Lower Limb Rehabilitation

This paper is focused on the development of a control system, implemented on a parallel robot designed for the lower limb rehabilitation of bedridden stroke survivors. The paper presents the RECOVER robotic system kinematics, further implemented into the control system, which is described in terms of architecture and functionality. Through a battery of experimental tests, achieved in laboratory conditions using eight healthy subjects, the feasibility and functionality of the proposed robotic system have been validated, and the overall performance of the control system has been studied. The range of motion of each targeted joint has been recorded using a commercially available external sensor system. The kinematic parameters, namely the patient’s joints velocities and accelerations have been recorded and compared to the ones obtained using the virtual model, yielding a very small difference between them, which provides a validation of the RECOVER initial design, both in terms of mechanical construction and control system.

Effects on the Motor Function, Proprioception, Balance, and Gait Ability of the End-Effector Robot-Assisted Gait Training for Spinal Cord Injury Patients

The primary aim of this study was to reveal the effects of end-effector robot-assisted gait training (RAGT) on motor function, proprioception, balance, and gait ability in patients with incomplete spinal cord injury (SCI). The secondary aim was to determine the correlation between clinical outcomes. This study was a prospective and multi-center study. A total of 13 incomplete SCI patients who met inclusion criteria received 30 min of RAGT with Morning Walk^® (Curexo, Seoul, South Korea), and 1 h of conventional physiotherapy 5 times per week for 4 weeks. Clinical outcome measures were 10 m walk test (10MWT), 6 min walk test (6mWT), lower extremity motor score (LEMS), proprioception, Berg Balance Scale (BBS), and Walking Index for Spinal Cord Injury (WISCI)-II. All participants were assessed within 48 h before and after the intervention. All clinical outcomes were statistically improved after RAGT. Subgroup analysis according to the initial proprioception, WISCI-II in the normal group showed a statistically significant improvement compared to the abnormal group. Initial BBS and WISCI-II had a positive correlation with most of the final clinical outcomes. The final BBS had a strong positive correlation with the final 10MWT, 6mWT, and WISCI-II. Initial proprioception had a positive correlation with the final WISCI-II. The final proprioception also had a moderate positive correlation with 6mWT and BBS. This study's results suggest that the end-effector RAGT could promote proprioception, balance ability and walking ability. Postural control ability and proprioception also had a positive relationship with gait ability.

Mechanically Assisted Neurorehabilitation: A Novel Six-Bar Linkage Mechanism for Gait Rehabilitation

Repeated and intensive gait training can improve muscle strength and movement coordination of patients with neurological or orthopedic impairments. However, conventional physical therapy by a physiotherapist is laborious and expensive. Therefore, this therapy is not accessible for the majority of patients. This paper presents a six-bar linkage mechanism for human gait rehabilitation with a natural ankle trajectory. Firstly, a six-bar linkage mechanism is selected as the original mechanism to construct a gait rehabilitation device. Then the ankle trajectory is formulated as a function of the crank angle. And the rotation angle of the crank is set as a linear function of time. Therefore, constant speed motor is sufficient to control the mechanism. For the dimensional synthesis, the precise point distances of the gait trajectory and the coupler curve are set as objective functions, with the kinematic constraints including in the optimization procedure. To obtain the optimal structure design parameters, a cooperative dual particle swarm optimization algorithm is developed. The results show that the coupler curve matches well with the gait trajectory. The average distance between the 60 precision points is 3.5 mm.

Robotic-assisted gait rehabilitation following stroke: a systematic review of current guidelines and practical clinical recommendations

INTRODUCTION

Stroke is the third leading cause of adult disability worldwide, and lower extremity motor impairment is one of the major determinants of long-term disability. Although robotic therapy is becoming more and more utilized in research protocols for lower limb stroke rehabilitation, the gap between research evidence and its use in clinical practice is still significant. The aim of this study was to determine the scope, quality, and consistency of guidelines for robotic lower limb rehabilitation after stroke, in order to provide clinical recommendations.

EVIDENCE ACQUISITION

We systematically reviewed stroke rehabilitation guideline recommendations between January 1, 2010 and October 31, 2020. We explored electronic databases (N.=4), guideline repositories and professional rehabilitation networks (N.=12). Two independent reviewers used the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument, and brief syntheses were used to evaluate and compare the different recommendations, considering only the most recent version.

EVIDENCE SYNTHESIS

From the 1219 papers screened, ten eligible guidelines were identified from seven different regions/countries. Four of the included guidelines focused on stroke management, the other six on stroke rehabilitation. Robotic rehabilitation is generally recommended to improve lower limb motor function, including gait and strength. Unfortunately, there is still no consensus about the timing, frequency, training session duration and the exact characteristics of subjects who could benefit from robotics.

CONCLUSIONS

Our systematic review shows that the introduction of robotic rehabilitation in standard treatment protocols seems to be the future of stroke rehabilitation. However, robot assisted gait training (RAGT) for stroke needs to be improved with new solutions and in clinical practice guidelines, especially in terms of applicability.

Exploiting telerobotics for sensorimotor rehabilitation: a locomotor embodiment

Background

Manual treadmill training is used for rehabilitating locomotor impairments but can be physically demanding for trainers. This has been addressed by enlisting robots, but in doing so, the ability of trainers to use their experience and judgment to modulate locomotor assistance on the fly has been lost. This paper explores the feasibility of a telerobotics approach for locomotor training that allows patients to receive remote physical assistance from trainers.

Methods

In the approach, a trainer holds a small robotic manipulandum that shadows the motion of a large robotic arm magnetically attached to a locomoting patient's leg. When the trainer deflects the manipulandum, the robotic arm applies a proportional force to the patient. An initial evaluation of the telerobotic system’s transparency (ability to follow the leg during unassisted locomotion) was performed with two unimpaired participants. Transparency was quantified by the magnitude of unwanted robot interaction forces. In a small six-session feasibility study, six individuals who had prior strokes telerobotically interacted with two trainers (separately), who assisted in altering a targeted gait feature: an increase in the affected leg’s swing length.

Results

During unassisted walking, unwanted robot interaction forces averaged 3−4 N (swing–stance) for unimpaired individuals and 2−3 N for the patients who survived strokes. Transients averaging about 10 N were sometimes present at heel-strike/toe-off. For five of six patients, these forces increased with treadmill speed during stance (R² = .99; p < 0.001) and increased with patient height during swing (R² = .71; p = 0.073). During assisted walking, the trainers applied 3.0 ± 2.8 N (mean ± standard deviation across patients) and 14.1 ± 3.4 N of force anteriorly and upwards, respectively. The patients exhibited a 20 ± 21% increase in unassisted swing length between Days 1−6 (p = 0.058).

Conclusions

The results support the feasibility of locomotor assistance with a telerobotics approach. Simultaneous measurement of trainer manipulative actions, patient motor responses, and the forces associated with these interactions may prove useful for testing sensorimotor rehabilitation hypotheses. Further research with clinicians as operators and randomized controlled trials are needed before conclusions regarding efficacy can be made.

Design and kinematic analysis of a novel rehabilitative robotic walking simulation device

This paper presents an original rehabilitative robotic walking simulation device. As a novel feature, it can duplicate the walking motion of the feet completely by including the motion of the metatarsophalangeal joints as well. It is also adjustable to different foot sizes and gait parameters such as speed, step length, and foot elevation. The presented device comprises two identical mechanisms that simulate the right and left feet. Each mechanism is designed as a planar parallel manipulator with three degrees of freedom and thus its platform (i.e. foot plate) can duplicate the sagittal-plane motion of a foot completely. A prototype of the device is already built, patented, and tested by several people, two of whom are physiotherapists. In the paper, the inverse and forward kinematic analyses of each parallel manipulator are also presented. The inverse kinematic analysis is carried out based on a typical gait cycle data of a healthy person gathered from the related literature. The results of the inverse kinematic analysis are then used as reference trajectory data in testing the device with different healthy people at different speeds.

Toward improving functional recovery in spinal cord injury using robotics: a pilot study focusing on ankle rehabilitation

Background: Conventional physical therapy interventions are strongly recommended to improve ambulation potential and upright mobility in persons with incomplete spinal cord injury (iSCI). Ankle rehabilitation plays a significant role, as it aims to stem drop foot consequences.Research question: This pilot study aimed to assess the neurophysiological underpinnings of robot-aided ankle rehabilitation (using a platform robot) compared to conventional physiotherapy and its efficacy in improving gait performance and balance in persons with iSCI.Methods: Ten individuals with subacute/chronic iSCI (six males and four females, 39 ± 13 years, time since injury 8 ± 4 months, ASIA impairment scale grade C-D) were provided with one-month intensive training for robot-aided ankle rehabilitation (24 sessions, 1 h daily, six times a week). Clinical (10-Meter Walk Test (10MWT), 6-Minute Walk Test (6MWT), and Timed Up and Go test (TUG)), and electrophysiological aftereffects (surface-EMG from tibialis anterior and medial gastrocnemius muscles to estimate muscle activation patterns; and corticomuscular coherence-CMC-to assess functional synchronization between sensorimotor cortex and muscles, i.e. the functional integrity of corticospinal output) were assessed at baseline (PRE) and after the trial completion (POST). The experimental group (EG) data were compared with those coming from a retrospective control group (CG; n = 10) matched for clinical-demographic characteristics, who previously underwent conventional ankle rehabilitation.Results: the EG achieved a greater improvement in balance and gait as compared to the CG (TUG EG from 70 ± 18 to 45 ± 15 s, p = 0.002; CG from 68 ± 21 to 48 ± 18 s, p = 0.01; group-comparison p = 0.001; 10MWT EG from 0.43 ± 0.11 to 0.51 ± 0.09 m/s, p = 0.006; CG from 0.4 ± 0.13 to 0.45 ± 0.12, p = 0.01; group-comparison p = 0.006; 6 MWT EG from 231 ± 13 to 274 ± 15 m, p < 0.001; CG from 236 ± 13 to 262 ± 15 m, p = 0.003; group-comparison p = 0.01). Furthermore, the EG showed a retraining of muscle activation (an increase within proper movements, with a reduction of co-contractions) and CMC (beta frequency increase within proper movements, i.e. in a framework of preserved motor coordination). The improvements in CMC, gait, balance, and muscle activation were not correlated with each other.Conclusions: Robot-aided ankle rehabilitation improved gait performance by selectively ameliorating CMC, muscle activation patterns, and, lastly, gait balance and speed. Despite CMC, gait, balance, and muscle activation were not correlated, this pilot study suggests that robot-aided ankle rehabilitation may favor a better communication between above-SCI and below-SCI structures. This communication improvement may depend on a more synchronized corticospinal output (as per CMC increase) and a better responsiveness of below-SCI motorneurons to corticospinal output (as per specific and ankle movement focused muscle activation increases at the surface EMG), thus favoring greater recruitment of spinal motor units and, ultimately, improving muscle activation pattern and strength.Significance: Adopting robot-aided ankle rehabilitation protocols for persons with iSCI in the subacute/chronic phase may allow achieving a clinically significant improvement in gait performance.

The Kickstart Walk Assist System for improving balance and walking function in stroke survivors: a feasibility study

BACKGROUND

Compared with traditional physical therapy for stroke patients, lower extremity exoskeletons can provide patients with greater endurance and more repeatable and controllable training, which can reduce the therapeutic burden of the therapist. However, most exoskeletons are expensive, heavy or require active power to be operated. Therefore, a lighter, easy to wear, easy to operate, low-cost technology for stroke rehabilitation would be a welcome opportunity for stroke survivors, caregivers and clinicians. One such device is the Kickstart Walk Assist system and the purpose of this study was to determine feasibility of using this unpowered exoskeleton device in a sample of stroke survivors.

METHODS

Thirty stroke survivors were enrolled in the study and experienced walking with the Kickstart exoskeleton device that provided spring-loaded assistance during gait. After 5 days of wearing the exoskeleton, participants were evaluated in the two states of wearing and not wearing the exoskeleton. Outcome measures included: (a) spatio-temporal gait measures, (b) balance measures and (c) exoskeleton-use feedback questionnaire.

RESULTS

In comparison to not wearing the device, when participants wore the Kickstart walking system, weight bearing asymmetry was reduced. The time spent on the 10-m walk test was also reduced, but there was no difference in the timed-up-and-go test (TUGT). Gait analysis data showed reduction in step time and double support time. Stroke survivors were positive about the Kickstart walking system's ability to improve their balance, speed and gait. In addition, their confidence level and willingness to use the device was also positive.

CONCLUSIONS

These findings show the feasibility of using the Kickstart walking system for improving walking performance in stroke survivors. Our future goal is to perform a longer duration study with more comprehensive pre- and post-testing in a larger sample of stroke survivors. Trial registration Chinese Clinical Trial Registry, ChiCTR2000032665. Registered 5 May 2020-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=53288.

Clinical Practice Guideline to Improve Locomotor Function Following Chronic Stroke, Incomplete Spinal Cord Injury, and Brain Injury

BACKGROUND

Individuals with acute-onset central nervous system (CNS) injury, including stroke, motor incomplete spinal cord injury, or traumatic brain injury, often experience lasting locomotor deficits, as quantified by decreases in gait speed and distance walked over a specific duration (timed distance). The goal of the present clinical practice guideline was to delineate the relative efficacy of various interventions to improve walking speed and timed distance in ambulatory individuals greater than 6 months following these specific diagnoses.

METHODS

A systematic review of the literature published between 1995 and 2016 was performed in 4 databases for randomized controlled clinical trials focused on these specific patient populations, at least 6 months postinjury and with specific outcomes of walking speed and timed distance. For all studies, specific parameters of training interventions including frequency, intensity, time, and type were detailed as possible. Recommendations were determined on the basis of the strength of the evidence and the potential harm, risks, or costs of providing a specific training paradigm, particularly when another intervention may be available and can provide greater benefit.

RESULTS

Strong evidence indicates that clinicians should offer walking training at moderate to high intensities or virtual reality-based training to ambulatory individuals greater than 6 months following acute-onset CNS injury to improve walking speed or distance. In contrast, weak evidence suggests that strength training, circuit (ie, combined) training or cycling training at moderate to high intensities, and virtual reality-based balance training may improve walking speed and distance in these patient groups. Finally, strong evidence suggests that body weight-supported treadmill training, robotic-assisted training, or sitting/standing balance training without virtual reality should not be performed to improve walking speed or distance in ambulatory individuals greater than 6 months following acute-onset CNS injury to improve walking speed or distance.

DISCUSSION

The collective findings suggest that large amounts of task-specific (ie, locomotor) practice may be critical for improvements in walking function, although only at higher cardiovascular intensities or with augmented feedback to increase patient's engagement. Lower-intensity walking interventions or impairment-based training strategies demonstrated equivocal or limited efficacy.

LIMITATIONS

As walking speed and distance were primary outcomes, the research participants included in the studies walked without substantial physical assistance. This guideline may not apply to patients with limited ambulatory function, where provision of walking training may require substantial physical assistance.

SUMMARY

The guideline suggests that task-specific walking training should be performed to improve walking speed and distance in those with acute-onset CNS injury although only at higher intensities or with augmented feedback. Future studies should clarify the potential utility of specific training parameters that lead to improved walking speed and distance in these populations in both chronic and subacute stages following injury.

DISCLAIMER

These recommendations are intended as a guide for clinicians to optimize rehabilitation outcomes for persons with chronic stroke, incomplete spinal cord injury, and traumatic brain injury to improve walking speed and distance.

Lower limb rehabilitation robotics: The current understanding and technology

BACKGROUND

With the increasing rate of ambulatory disabilities and rise in the elderly population, advance methods to deliver the rehabilitation and assistive services to patients have become important. Lower limb robotic therapeutic and assistive aids have been found to improve the rehabilitation outcome.

OBJECTIVE

The article aims to present the updated understanding in the field of lower limb rehabilitation robotics and identify future research avenues.

METHODS

Groups of keywords relating to assistive technology, rehabilitation robotics, and lower limb were combined and searched in EMBASE, IEEE Xplore Digital Library, Scopus, Web of Science and Google Scholar database.

RESULTS

Based on the literature collected from the databases we provide an overview of the understanding of robotics in rehabilitation and state of the art devices for lower limb rehabilitation. Technological advancements in rehabilitation robotic architecture (sensing, actuation and control) and biomechanical considerations in design have been discussed. Finally, a discussion on the major advances, research directions, and challenges is presented.

CONCLUSIONS

Although the use of robotics has shown a promising approach to rehabilitation and reducing the burden on caregivers, extensive and innovative research is still required in both cognitive and physical human-robot interaction to achieve treatment efficacy and efficiency.

Occurrence and Type of Adverse Events During the Use of Stationary Gait Robots-A Systematic Literature Review

Robot-assisted gait training (RAGT) devices are used in rehabilitation to improve patients' walking function. While there are some reports on the adverse events (AEs) and associated risks in overground exoskeletons, the risks of stationary gait trainers cannot be accurately assessed. We therefore aimed to collect information on AEs occurring during the use of stationary gait robots and identify associated risks, as well as gaps and needs, for safe use of these devices. We searched both bibliographic and full-text literature databases for peer-reviewed articles describing the outcomes of stationary RAGT and specifically mentioning AEs. We then compiled information on the occurrence and types of AEs and on the quality of AE reporting. Based on this, we analyzed the risks of RAGT in stationary gait robots. We included 50 studies involving 985 subjects and found reports of AEs in 18 of those studies. Many of the AE reports were incomplete or did not include sufficient detail on different aspects, such as severity or patient characteristics, which hinders the precise counts of AE-related information. Over 169 device-related AEs experienced by between 79 and 124 patients were reported. Soft tissue-related AEs occurred most frequently and were mostly reported in end-effector-type devices. Musculoskeletal AEs had the second highest prevalence and occurred mainly in exoskeleton-type devices. We further identified physiological AEs including blood pressure changes that occurred in both exoskeleton-type and end-effector-type devices. Training in stationary gait robots can cause injuries or discomfort to the skin, underlying tissue, and musculoskeletal system, as well as unwanted blood pressure changes. The underlying risks for the most prevalent injury types include excessive pressure and shear at the interface between robot and human (cuffs/harness), as well as increased moments and forces applied to the musculoskeletal system likely caused by misalignments (between joint axes of robot and human). There is a need for more structured and complete recording and dissemination of AEs related to robotic gait training to increase knowledge on risks. With this information, appropriate mitigation strategies can and should be developed and implemented in RAGT devices to increase their safety.

Brain Connectivity Modulation After Exoskeleton-Assisted Gait in Chronic Hemiplegic Stroke Survivors: A Pilot Study

OBJECTIVE

The aim of this study was to investigate electroencephalographic (EEG) connectivity short-term changes, quantified by node strength and betweenness centrality, induced by a single trial of exoskeleton-assisted gait in chronic stroke survivors.

DESIGN

Study design was randomized crossover. Electroencephalographic data (64-channel system) were recorded before gait (baseline) and after unassisted overground walking and overground exoskeleton-assisted walking. Coherence was estimated for alpha1, alpha2, and beta frequency ranges. Graph analysis assessed network model properties: node strength and betweenness centrality.

RESULTS

Nine participants were included in the final analysis. In the group (four participants) with a left-hemisphere stroke lesion (dominant hemisphere), over the vertex, node strength increased in alpha1, alpha2, and beta bands, and betweenness centrality decreased in alpha2 both after unassisted overground walking and exoskeleton-assisted walking. In the group (five participants) with a right-hemisphere lesion (nondominant hemisphere), node strength increased in alpha1 and alpha2 over the contralesional sensorimotor area and ipsilesional prefrontal area after overground exoskeleton-assisted walking, compared with baseline and unassisted overground walking.

CONCLUSION

A single session of exoskeleton training provides short-term neuroplastic modulation in chronic stroke. In participants with a nondominant hemisphere lesion, exoskeleton training induces activations similar to those observed in able-bodied participants, suggesting a role of lesion lateralization in networks' reorganization.

Development of an Improved Rotational Orthosis for Walking With Arm Swing and Active Ankle Control

Based on interlimb neural coupling, gait robotic systems should produce walking-like movement in both upper and lower limbs for effective walking restoration. Two orthoses were previously designed in our lab to provide passive walking with arm swing. However, an active system for walking with arm swing is desirable to serve as a testbed for investigation of interlimb neural coupling in response to voluntary input. Given the important function of the ankle joint during normal walking, this work aimed to develop an improved rotational orthosis for walking with arm swing, which is called ROWAS II, and especially to develop and evaluate the algorithms for active ankle control. After description of the mechanical structure and control schemes of the overall ROWAS II system, the closed-loop position control and adjustable admittance control algorithms were firstly deduced, then simulated in Matlab/Simulink and finally implemented in the ROWAS II system. Six able-bodied participants were recruited to use the ROWAS II system in passive mode, and then to estimate the active ankle mechanism. It was showed that the closed-loop position control algorithms enabled the ROWAS II system to track the target arm-leg walking movement patterns well in passive mode, with the tracking error of each joint <0.7°. The adjustable admittance control algorithms enabled the participants to voluntarily adjust the ankle movement by exerting various active force. Higher admittance gains enabled the participants to more easily adjust the movement trajectory of the ankle mechanism. The ROWAS II system is technically feasible to produce walking-like movement in the bilateral upper and lower limbs in passive mode, and the ankle mechanism has technical potential to provide various active ankle training during gait rehabilitation. This novel ROWAS II system can serve as a testbed for further investigation of interlimb neural coupling in response to voluntary ankle movement and is technically feasible to provide a new training paradigm of walking with arm swing and active ankle control.

A Review of Robot-Assisted Lower-Limb Stroke Therapy: Unexplored Paths and Future Directions in Gait Rehabilitation

Stroke affects one out of every six people on Earth. Approximately 90% of stroke survivors have some functional disability with mobility being a major impairment, which not only affects important daily activities but also increases the likelihood of falling. Originally intended to supplement traditional post-stroke gait rehabilitation, robotic systems have gained remarkable attention in recent years as a tool to decrease the strain on physical therapists while increasing the precision and repeatability of the therapy. While some of the current methods for robot-assisted rehabilitation have had many positive and promising outcomes, there is moderate evidence of improvement in walking and motor recovery using robotic devices compared to traditional practice. In order to better understand how and where robot-assisted rehabilitation has been effective, it is imperative to identify the main schools of thought that have prevailed. This review intends to observe those perspectives through three different lenses: the goal and type of interaction, the physical implementation, and the sensorimotor pathways targeted by robotic devices. The ways that researchers approach the problem of restoring gait function are grouped together in an intuitive way. Seeing robot-assisted rehabilitation in this unique light can naturally provoke the development of new directions to potentially fill the current research gaps and eventually discover more effective ways to provide therapy. In particular, the idea of utilizing the human inter-limb coordination mechanisms is brought up as an especially promising area for rehabilitation and is extensively discussed.

Measurement and Analysis of Gait Pattern during Stair Walk for Improvement of Robotic Locomotion Rehabilitation System

Background

Robotic locomotion rehabilitation systems have been used for gait training in patients who have had a stroke. Most commercialized systems allow patients to perform simple exercises such as balancing or level walking, but an additional function such as stair-walk training is required to provide a wide range of recovery cycle rehabilitation. In this study, we analyzed stair-gait patterns and applied the result to a robotic rehabilitation system that can provide a vertical motion of footplates.

Methods

To obtain applicable data for the robotic system with vertically movable footplates, stair-walk action was measured using an optical marker-based motion capture system. The spatial position data of joints during stair walking was obtained from six healthy adults who participated in the experiment. The measured marker data were converted into joint kinematic data by using an algorithm that included resampling and normalization. The spatial position data are represented as angular trajectories and the relative displacement of each joint on the anatomical sagittal plane and movements of hip joints on the anatomical transverse plane.

Results

The average range of motion (ROM) of each joint was estimated as (−6.75°, 48.69°) at the hip, (8.20°, 93.78°) at the knee, and (−17.78°, 11.75°) at the ankle during ascent and as (6.41°, 31.67°) at the hip, (7.38°, 91.93°) at the knee, and (−24.89°, 24.18°) at the ankle during descent. Additionally, we attempted to create a more natural stair-gait pattern by analyzing the movement of the hip on the anatomical transverse plane. The hip movements were estimated to within ±1.57 cm and ±2.00 cm for hip translation and to within ±2.52° and ±2.70° for hip rotation during stair ascent and stair descent, respectively.

Conclusions

Based on the results, standard patterns of stair ascent and stair descent were derived and applied to a lower-limb rehabilitation robot with vertically movable footplates. The relative trajectory from the experiment ascertained that the function of stair walking in the robotic system properly worked within a normal ROM.

Pediatric Traumatic Brain Injury and Exercise Medicine: A Narrative Review

The multidisciplinary field of pediatric traumatic brain injury (TBI) and exercise medicine is of growing importance. There is active study into the diagnostic and therapeutic potential of exercise in pediatric TBI as well as the effects of TBI on postinjury fitness. With the evidence-based growing, a literature review can help establish the state of the science and inform future research. Therefore, the authors performed a narrative review (based on a search of 6 health sciences databases) to summarize evidence on pediatric TBI and cardiorespiratory fitness, muscular fitness and neuromotor control, and obesity. To date, studies related to cardiorespiratory fitness have centered on exercise tolerance and readiness to return to play, and indicate that protracted rest may not facilitate symptom recovery; this suggests a role for exercise in concussion management. Furthermore, strength and gait may be impaired following pediatric brain injury, and interventions designed to train these impairments may lead to their improvement. Pediatric brain injury can also lead to changes in body composition (which may be related to poorer cognitive recovery), but additional research is required to better understand such associations. This narrative review of pediatric TBI and exercise medicine can serve as a reference for researchers and clinicians alike.

Exoskeleton and End-Effector Robots for Upper and Lower Limbs Rehabilitation: Narrative Review

Recovery of upper and lower limbs function is essential to reach independence in daily activities in patients with upper motor neuron syndrome (UMNS). Rehabilitation can provide a guide for motor recovery influencing the neurobiology of neuronal plasticity providing controlled, repetitive, and variable patterns. Increasing therapy dosage, intensity, number of repetition, execution of task-oriented exercises, and combining top-down and bottom-up approaches can promote plasticity and functional recovery. Robotic exoskeletons for upper and lower limbs, based on the principle of motor learning, have been introduced in neurorehabilitation. In this narrative review, we provide an overview of literature published on exoskeleton devices for upper and lower limb rehabilitation in patients with UMNS; we summarized the available current research evidence and outlined the new challenges that neurorehabilitation and bioengineering will have to face in the upcoming years. Robotic treatment should be considered a rehabilitation tool useful to generate a more complex, controlled multisensory stimulation of the patient and useful to modify the plasticity of neural connections through the experience of movement. Efficacy and efficiency of robotic treatment should be defined starting from intensity, complexity, and specificity of the robotic exercise, that are related to human-robot interaction in terms of motion, emotion, motivation, meaning of the task, feedback from the exoskeleton, and fine motion assistance. Duration of a single session, global period of the treatment, and the timing for beginning of robotic treatment are still open questions. There is the need to evaluate and individualize the treatment according to patient's characteristics. Robotic devices for upper and lower limbs open a window to define therapeutic modalities as possible beneficial drug, able to boost biological, neurobiological, and epigenetic changes in central nervous system. We need to implement large and innovative research programs to answer these issues in the near future.

Is Robotic Gait Training Feasible in Adults With Disorders of Consciousness?

OBJECTIVE

To investigate the feasibility and safety of robotic-assisted gait training (RAGT) in adults with disorders of consciousness (DoC).

SETTING

Inpatient rehabilitation hospital.

PARTICIPANTS

Four adult male patients with traumatic brain injury and DoC.

DESIGN

Subjects participated in RAGT with body weight support for 5 to 20 minutes, over 1- to 2-week periods.

MAIN MEASURES

Primary measures included vital signs, walking parameters, pain, arousal, and Agitation Behavior Scale scores. Additional data included Modified Ashworth Scale, Coma Recovery Scale-Revised, and Rancho Los Amigos Scale scores.

RESULTS

All participants safely completed at least one session of RAGT with body weight support with safe vital signs and low agitation levels. Two adverse events occurred (increased somnolence and pain due to harness placement), which were not considered severe. All subjects emerged out of DoC at which point research protocol was stopped.

CONCLUSIONS

Findings suggest inpatient-based RAGT may be safe and feasible to consider when developing a therapy plan of care in adults with DoC.

Perspectives and Challenges in Robotic Neurorehabilitation

The development of robotic devices for rehabilitation is a fast-growing field. Nowadays, thanks to novel technologies that have improved robots’ capabilities and offered more cost-effective solutions, robotic devices are increasingly being employed during clinical practice, with the goal of boosting patients’ recovery. Robotic rehabilitation is also widely used in the context of neurological disorders, where it is often provided in a variety of different fashions, depending on the specific function to be restored. Indeed, the effect of robot-aided neurorehabilitation can be maximized when used in combination with a proper training regimen (based on motor control paradigms) or with non-invasive brain machine interfaces. Therapy-induced changes in neural activity and behavioral performance, which may suggest underlying changes in neural plasticity, can be quantified by multimodal assessments of both sensorimotor performance and brain/muscular activity pre/post or during intervention. Here, we provide an overview of the most common robotic devices for upper and lower limb rehabilitation and we describe the aforementioned neurorehabilitation scenarios. We also review assessment techniques for the evaluation of robotic therapy. Additional exploitation of these research areas will highlight the crucial contribution of rehabilitation robotics for promoting recovery and answering questions about reorganization of brain functions in response to disease.

Gait-phase-dependent control using a smart walker for physical training

Falling has become a key factor that affects the quality of life of the elderly. Currently, the use of a few rehabilitation robots can contribute to the restoration of balance. In this paper, a walker-based rehabilitation robot with a gait-phasedependent control algorithm is proposed to promote dynamic balance in the elderly. It has unique characteristics in that the level of the walker to resist the propulsion force exerted by a user can vary depending on the gait-phase that is estimated using the interaction force between the robot and the user. The robot efficiently improves the muscle power of various muscle groups of the user. Experiments with three young subjects were conducted to validate the effectiveness of the walker with the gait-phase-dependent control algorithm.

Lower limb rehabilitation using multimodal measurement of sit-to-stand and stand-to-sit task

PURPOSE

Assistive and rehabilitation devices are dependent upon detecting the user intent through physiological and kinematics changes. Rising from a chair and vice-versa have been less investigated for the purpose of rehabilitation-aids. This study investigates the muscle activation along with trunk and knee biomechanics in sagittal plane during sit-to-stand and stand-to-sit transfer.

METHOD

Nine healthy participants (age 25.67 ± 3.27 years) were measured for flexion/extension of knee and trunk, and for surface electromyography (EMG) of vastus lateralis (VL) and biceps femoris (BF) of both the legs at a speed of 100 beats per minute while performing sit-to-stand and stand-to-sit task.

RESULTS

The knee flexion angles at peak EMG-RMS (root mean square envelope of EMG) were significantly different for the two tasks (p = 0.002). Also, for each muscle, EMG-RMS peak was obtained at significantly different knee angle within the same task (p = 0.046). EMG work done (WD) was also found to be significantly different for the intervened muscles (p = 0.002).

CONCLUSIONS

Trunk flexion together with VL showed an earlier onset in sit-to-stand task, which might form an important modality for detecting human intention to perform the activity. However, for stand-to-sit task, some other muscle group in conjunction to BF may be useful for detecting the human intention. The understanding from the study could be used as a first step in devising multimodal control for assistive devices aiding sit-to-stand and stand-to-sit transfers. That would be a novel approach to fuse the data of postural deviation into the EMG signal to achieve lower limb rehabilitation or in prosthetic control.Implications for rehabilitationMulti-modal sensor fusion can be used for realtime monitoring of patient biomechanics.Development of control algorithms for assistive devices aiding sit-stand transfers.Sensor fusion will help in achieving greater robotic compliance rehabilitation.

Stroke Gait Rehabilitation: A Comparison of End-Effector, Overground Exoskeleton, and Conventional Gait Training

Gait recovery is one of the main goals of post-stroke rehabilitation and Robot-Assisted Gait Training (RAGT) has shown positive outcomes. However, there is a lack of studies in the literature comparing the effects of different devices. This paper aims to study the effects, in terms of clinical and gait outcomes, of treadmill-based and overground RAGT, compared to conventional gait training in stroke subjects. The results showed a significant improvement of clinical outcomes in both robotic treatments and in conventional therapy. The performance of locomotor tasks was clinically significant in the robotic groups only. The spatio-temporal gait parameters did not reveal any significant difference. Results suggest future multicentre studies on a larger number of subjects.

Admittance Control of the Ankle Mechanism in a Rotational Orthosis for Walking with Arm Swing

In order to provide an effective system for rehabilitation of walking, a new rotational orthosis for walking with arm swing, called ROWAS II, was developed. This study focused on development and implementation of admittance control of the ankle mechanism in the ROWAS II system for promoting active training. Firstly, the mechanical structure of the ankle mechanism is briefly introduced. Then the algorithms of the closed-loop position control and the admittance control for the ankle mechanism are described in detail. Four able-bodied participants were recruited to use the ankle mechanism running in passive and active modes. The experimental results showed that the ankle mechanism well tracked the target trajectory in passive mode. In active mode, the participants interacted with the ankle mechanism, and adjusted their ankle movement based on their active force. The ankle mechanism has the technical potential to meet the requirements of passive and active training in the ankle movement for patients in different post-stroke stages.

The effects of locomotor training in children with spinal cord injury: a systematic review

PURPOSE

Discuss the effectiveness of locomotor training (LT) in children following spinal cord injury (SCI). This intervention was assessed following an exhaustive search of the literature using the Preferred Reporting Items for Systematic Reviews and Meta- Analyses: The PRISMA Statement as a guideline.

METHOD

Six databases were searched including PubMed, PEDro, CINAHL, Cochrane, PsycINFO, and Web of Knowledge in January 2016 and November 2016, without date restrictions. Inclusion criteria were: studies in English and peer-reviewed and journal articles with a primary intervention of LT in children following SCI.

RESULTS

Twelve articles, reporting eleven studies, were included. A systematic review assessing locomotor training in children with SCI published in April 2016 was also included. Participants were ages 15 months to 18 years old. Forms of LT included body-weight supported treadmill or over ground training, functional electrical stimulation, robotics, and virtual reality. Protocols differed in set-up and delivery mode, with improvements seen in ambulation for all 41 participants following LT.

CONCLUSION

Children might benefit from LT to develop or restore ambulation following SCI. Age, completeness, and level of injury remain the most important prognostic factors to consider with this intervention. Additional benefits include improved bowel/ bladder management and control, bone density, cardiovascular endurance, and overall quality of life. Looking beyond the effects LT has just on ambulation is crucial because it can offer benefits to all children sustaining a SCI, even if restoration or development of walking is not the primary goal. Further rigorous research is required to determine the overall effectiveness of LT.

Human–robot interactive control based on reinforcement learning for gait rehabilitation training robot

A human–robot interactive control is proposed to govern the assistance provided by a lower limb exoskeleton robot to patients in the gait rehabilitation training. The rehabilitation training robot with two lower limb exoskeletons is driven by the pneumatic proportional servo system and has two rotational degrees of freedom of each lower limb. An adaptive admittance model is adopted considering its suitability for human–robot interaction. The adaptive law of the admittance parameters is designed with Sigmoid function and the reinforcement learning algorithm. Individualized admittance parameters suitable for patients are obtained by reinforcement learning. Experiments in passive and active rehabilitation training modes were carried out to verify the proposed control method. The passive rehabilitation training experimental results verify the effectiveness of the inner-loop position control strategy, which can meet the demands of gait tracking accuracy in rehabilitation training. The active rehabilitation training experimental results demonstrate that the personal adaption and active compliance are provided by the interactive controller in the robot-assistance for patients. The combined effects of flexibility of pneumatic actuators and compliance provided by the controller contribute to the training comfort, safety, and therapeutic outcome in the gait rehabilitation.

Robot-assisted ankle rehabilitation: a review

Aim: The aim of this review paper is to summarize recent developments and research in robotics, relevant to the field of ankle rehabilitation, to overview new findings and determine the actual state of the art.Method: The literature search was performed using scientific and medical databases (Scopus, PubMed and Web of Science) and other websites related to robots used in the area of ankle rehabilitation, analysing studies from 1950s to present. Information about the mechanical and kinematic specifications, actuation and stage of development was extracted from the selected literature.Results: Several types of rehabilitation robots have been considered, and they were classified depending on their architecture and design features. We we found that, regardless of the differences in architectures, only a few of them have been commercialized. The majority of rehabilitation robots designs allows plantarflexion-dorsiflexion movements. Unless some exceptions, most of the wearable robots do not allow the adduction-abduction movement. Neither the physical appearance of the robot nor the user's perception towards it has not regularly been taken into account in the design stage. This limits the possibility of successful commercialization.Conclusions: Up to the present moment, the main challenges in the field of robot rehabilitation are the lack of unique rehabilitation protocols capable to fulfil the needs of all types of patients and the additional resources to measure the effectiveness of proposals that have not yet been commercialized. Nonetheless, we have mentioned above three areas were the challenges in design are more pressing. The first one is the robot architecture, which still presents some incommodities nowadays to emulate the ankle joint movement in a natural way. Thus, the displacements experienced by the axes in the joint must be adaptable to each patient and a wide range of pathologies. Moreover, many proposals are not been conceived to the purpose of commercialization, and even less to become an object of personal use.Implications for rehabilitationThis review states that the use of robotic devices for ankle rehabilitation is a consolidated paradigm in the ankle's rehabilitation.Platform-based robots allow to do complex and specialized spatial movements and these architectures endow the device with high stiffness, a balanced force distribution and better adaptability to the mechanical properties of human ankle joints. Unless some exceptions, most of the wearable robots do not allow the adduction-abduction movement.For a full integration of these technologies in the ankle's rehabilitation field, more clinical evaluations are needed.Regardless of the potential of robotic devices in rehabilitation, only a few of them have been commercialized.

Overground wearable powered exoskeleton for gait training in subacute stroke subjects: clinical and gait assessments

BACKGROUND

Wearable powered exoskeletons provide intensive overground gait training with patient's active participation: these features promote a successful active motor relearning of ambulation in stroke survivors.

AIM

The aim of this study was to investigate the feasibility and the clinical effects of an overground exoskeleton-assisted gait training (OEAGT) in subacute stroke patients.

DESIGN

Prospective, pilot pre-post, open label, non-randomized experimental study.

SETTING

Four Italian neurological rehabilitation centers.

POPULATION

Forty-eight subacute stroke patients were enrolled. Two patients dropped out because of medical problems. Data analysis was conducted on 46 subjects (56.84±14.29 years; 27 male; 29 ischemic; 24 left hemiparesis).

METHODS

Patients underwent 15±2 sessions (60 min/session, 3-5 times/week) of OEAGT. Clinical and gait assessments were performed at the beginning (T1) and at the end (T2) of the training period: modified Barthel Index (BI), modified Ashworth Scale at Hip (MAS-H), Knee (MAS-K), and Ankle (MAS-A) level, Motricity Index (MI), Trunk Control Test (TCT), Functional Ambulation Classification (FAC), Walking Handicap Scale (WHS), 10-Meter Walking Test (10MWT), 6-Minute Walking Test (6mWT), Timed Up-and-Go test (TUG). The Technology Acceptance Model (TAM) questionnaire evaluated the acceptance of OEAGT by patients. Data stratification was performed using the time post the acute event and the onset of rehabilitation treatment, and the MI at T1. Wilcoxon's test (P<0.05) was used.

RESULTS

All clinical scales significantly improved at T2; no statistically significant changes were reported for MAS-H, MAS-K, MAS-A. The 69.57% patients were able to walk at T1; 17.39% were not able to walk at T1 but regained ambulation at T2; and 13.04% were not able to walk at either T1 or T2. The ambulant patients showed a statistical improvement in speed measured during the 10MWT and in the distance covered over a time of 6 minutes (6mWT). The results from the TAM questionnaire showed that all subjects perceived the OEAGT positively. The data stratification analysis suggests that the OEAGT does not have any restriction of use.

CONCLUSIONS

The OEAGT improved the clinical and gait outcomes in subacute patients. Randomized studies on larger samples are needed to confirm these data and to assess the efficacy of OEAGT.

CLINICAL REHABILITATION IMPACT

Introduce innovative rehabilitation strategies based on customized OEAGT.

Conceptual design and dimensional synthesis of a novel parallel mechanism for lower-limb rehabilitation

This paper introduces a novel 2R1T parallel manipulator redundantly actuated by pneumatic muscles for lower-limb rehabilitation. First, the conceptual design of the proposed 3-DOF parallel mechanism is presented. Then, the inverse kinematics and the generalized Jacobian analysis are carried out. Based on the generalized Jacobian and the constraint characteristics of the mechanism, the force/motion transmissibility of the redundantly actuated parallel mechanism is investigatedviafour individual cases without actuation redundancy, leading to a suitable local transmission index for the evaluation of kinematic performance of the proposed mechanism. Finally, the design variables are optimized by maximizing the mean value of the local transmission index with the aid of genetic algorithm. The numerical result shows that the proposed parallel mechanism can achieve a good kinematic performance in its task workspace.

Robot-assisted training using Hybrid Assistive Limb® for cerebral palsy

PURPOSE

The Hybrid Assistive Limb® (HAL®, CYBERDYNE) is a wearable robot that provides assistance to a patient while they are walking, standing, and performing leg movements based on the wearer's intended movement. The effect of robot-assisted training using HAL® for cerebral palsy (CP) is unknown. Therefore, we assessed the effect of robot-assisted training using HAL® on patients with CP, and compared walking and gross motor abilities between pre-intervention and post-intervention.

METHODS

Six subjects with CP were included (mean age: 16.8 years; range: 13-24 years; Gross Motor Function Classification System levels II-IV: n = 1, 4, 1). Robot-assisted training using HAL® were performed 2-4 sessions per week, 20 min per session, within a 4 weeks period, 12 times in total. Outcome measures included gait speed, step length, cadence, single-leg support per gait cycle, hip and knee joint angle in stance, and swing phase per gait cycle, 6-minute walking distance (6 MD), physiological cost index (PCI), knee-extension strength, and Gross Motor Function Measure (GMFM).

RESULTS

There were significant increases in self-selected walking speed (SWS), cadence during SWS and maximum walking speed (MWS), single-leg support per gait cycle, hip joint angle in the swing phase, 6 MD, and GMFM. In contrast, gait speed during MWS, step length during SWS and MWS, hip and knee joint angle in the stance phase, knee joint angle in the swing phase, PCI, and knee-extension strength generally improved, but not significantly.

CONCLUSION

Robot-assisted training using HAL® may improve walking and gross motor abilities of patients with CP.

Current state of balance assessment during transferring, sitting, standing and walking activities for the spinal cord injured population: A systematic review

CONTEXT

Comprehensive balance measures with high clinical utility and sound psychometric properties are needed to inform the rehabilitation of individuals with spinal cord injury (SCI).

OBJECTIVE

To identify the balance measures used in the SCI population, and to evaluate their clinical utility, psychometric properties and comprehensiveness.

METHODS

Medline, PubMed, Embase, Scopus, Web of Science, and the Allied and Complementary Medicine Database were searched from the earliest record to October 19/16. Two researchers independently screened abstracts for articles including a balance measure and adults with SCI. Extracted data included participant characteristics and descriptions of balance measures. Quality was evaluated by considering study design, sampling method and adequacy of description of research participants. Clinical utility of all balance measures was evaluated. Comprehensiveness was evaluated using the modified Systems Framework for Postural Control.

RESULTS

2820 abstracts were returned and 127 articles included. Thirty-one balance measures were identified; 11 evaluated a biomechanical construct and 20 were balance scales. All balance scales had high clinical utility. The Berg Balance Scale and Functional Reach Test were valid and reliable, while the mini-BESTest was the most comprehensive.

CONCLUSION

No single measure had high clinical utility, strong psychometric properties and comprehensiveness. The mini-BESTest and/or Activity-based Balance Level Evaluation may fill this gap with further testing of their psychometric properties.

Mechanical design and trajectory planning of a lower limb rehabilitation robot with a variable workspace

The early phase of extremity rehabilitation training has high potential impact for stroke patients. However, most of the lower limb rehabilitation robots in hospitals are proposed just suitable for patients at the middle or later recovery stage. This article investigates a new sitting/lying multi-joint lower limb rehabilitation robot. It can be used at all recovery stages, including the initial stage. Based on man–machine engineering and the innovative design for mechanism, the leg length of the lower limb rehabilitation robot is automatically adjusted to fit patients with different heights. The lower limb rehabilitation robot is a typical human–machine system, and the limb safety of the patient is the most important principle to be considered in its design. The hip joint rotation ranges are different in people’s sitting and lying postures. Different training postures cannot make the training workspace unique. Besides the leg lengths and joint rotation angles varied with different patients, the idea of variable workspace of the lower limb rehabilitation robot is first proposed. Based on the variable workspace, three trajectory planning methods are developed. In order to verify the trajectory planning methods, an experimental study has been conducted. Theoretical and actual curves of the hip rotation, knee rotation, and leg mechanism end point motion trajectories are obtained for three unimpaired subjects. Most importantly, a clinical trial demonstrated the safety and feasibility of the proposed lower limb rehabilitation robot.

A narrative review of gait training after stroke and a proposal for developing a novel gait training device that provides minimal assistance

BACKGROUND

Gait impairment is common in stroke survivors. Recovery of walking ability is one of the most pressing objectives in stroke rehabilitation.

OBJECTIVES

Of this report are to briefly review recent progress in gait training after stroke including the use of partial body weight-supported treadmill training (PBWSTT) and robot-assisted step training (RAST), and propose a minimal assistance strategy that may overcome some of limitations of current RAST.

METHODS

The literature review emphasizes a dilemma that recent randomized clinical trials did not support the use of RAST. The unsatisfactory results of current RAST clinical trials may be partially due to a lack of careful analysis of movement deficiencies and their relevance to gait training task specificity after stroke. Normal movement pattern is implied to be part of task specificity in the current RAST. Limitations of such task specificity are analyzed.

RESULTS

Based on the review, we redefine an alternative set of gait training task specificity that represents a minimal assistance strategy in terms of assisted body movements and amount of assistance. Specifically, assistances are applied only to hip flexion and ankle dorsiflexion of the affected lower limb during swing phase. Furthermore, we propose a conceptual design of a novel device that may overcome limitations of current RAST in gait training after stroke. The novel device uses a pulling cable, either manually operated by a therapist or automated by a servomotor, to provide assistive forces to help hip flexion and ankle dorsiflexion of the affected lower limb during gait training.

CONCLUSION

The proposed minimal assistance strategy may help to design better devices for gait or other motor training.

A review in gait rehabilitation devices and applied control techniques

PURPOSE

The aim of this review is to analyse the different existing technologies for gait rehabilitation, focusing mainly in robotic devices. Those robots help the patient to recover a lost function due to neurological gait disorders, accidents or after injury. Besides, they facilitate the identification of normal and abnormal features by registering muscle activity providing the doctor important data where he can observe the evolution of the patient.

METHOD

A deep literature review was realized using selected keywords considering not only the most common medical and engineering databases, but also other available sources that provide information on commercial and scientific gait rehabilitation devices. The founded literature for this review corresponds to control techniques for gait rehabilitation robots, since the early seventies to the present year.

RESULTS

Different control strategies for gait analysis in rehabilitation devices have been developed and implemented such as position control, force and impedance control, haptic simulation, and control of EMG signals. These control techniques are used to analyze the force of the patient during therapy, compensating it with the force generated by the mechanism in the rehabilitation device. It is observed that the largest number of studies reported, focuses on the impedance control technique. Leading to include new control techniques and validate them using the necessary protocols with ill patients, obtaining reliable results that allows a progressive and active rehabilitation.

CONCLUSIONS

With this exhaustive review, we can conclude that the degree of complexity of the rehabilitation device influences in short and long-term therapeutic results since the movements become more controlled. However, there is still a lot of work in the sense of motion control in order to perform trajectories that are more alike the natural movements of humans. There are many control techniques in other areas, which seek to improve the performance of the process. These techniques may possibly be applicable in gait rehabilitation devices, obtaining controllers that are more efficient and that adapts to different people and the necessities that entail every disease. Implications for Rehabilitation Rehabilitation helps people to improve the activities of their daily life, allowing them to observe their progress in the functional abilities as the months pass by with intensive and repetitive therapies. There is a mobility issue when the patient needs to move to the hospital or to the laboratory, which is not always feasible. For overcoming it, patients use the equipment at home to perform their daily therapy. However, they need the sufficient knowledge about its operation, also about the therapeutic movements, the therapy duration and the movement speed. Besides, is necessary to place the equipment in a proper and lively environment that helps to forget or reduce pain while the patient moves his joints progressively. The purpose of robotic rehabilitation devices is to generate repetitive and progressive movements, according to the motor disability. There are training trajectories to follow, which motivate patients to generate active movements. The benefits of robotic rehabilitation depend on the ability of each patient to adapt to the speed and load variations generated by the device, improving and reinforcing motor functions in therapy, especially in patients with advanced disabilities in early rehabilitation. Multi-joint rehabilitation devices are more effective than single-joint rehabilitation devices because they involve a higher number of muscles in the therapy. The greater the number of degrees of freedom (DoF) of the device, it cushions its effect in the patient because the inertia is reduced and higher torques are generated. The assistive technological devices allows to explore different rehabilitation techniques that motivate the patient in therapy, increasing appropriately the energy and pressure in the blood which is reflected in gradually recovering his ability to walk.

Immediate effects of a single session of robot-assisted gait training using Hybrid Assistive Limb (HAL) for cerebral palsy

[Purpose] Robot-assisted gait training (RAGT) using Hybrid Assistive Limb (HAL, CYBERDYNE) was previously reported beneficial for stroke and spinal cord injury patients. Here, we investigate the immediate effect of a single session of RAGT using HAL on gait function for cerebral palsy (CP) patients. [Subjects and Methods] Twelve patients (average age: 16.2 ± 7.3 years) with CP received a single session of RAGT using HAL. Gait speed, step length, cadence, single-leg support per gait cycle, hip and knee joint angle in stance, and swing phase per gait cycle were assessed before, during, and immediately after HAL intervention. [Results] Compared to baseline values, single-leg support per gait cycle (64.5 ± 15.8% to 69.3 ± 12.1%), hip extension angle in mid-stance (149.2 ± 19.0° to 155.5 ± 20.1°), and knee extension angle in mid-stance (137.6 ± 20.2° to 143.1 ± 19.5°) were significantly increased immediately after intervention. Further, the knee flexion angle in mid-swing was significantly decreased immediately after treatment (112.0 ± 15.5° to 105.2 ± 17.1°). Hip flexion angle in mid-swing also decreased following intervention (137.2 ± 14.6° to 129.7 ± 16.6°), but not significantly. Conversely, gait speed, step length, and cadence were unchanged after intervention. [Conclusion] A single-time RAGT with HAL improved single-leg support per gait cycle and hip and knee joint angle during gait, therapeutically improving gait function in CP patients.

Design, optimisation and testing of a compact, inexpensive elastic element for series elastic actuators

This paper presents the development of a compact torsion spring for use as an elastic element in a lightweight series elastic actuator for an active orthosis. This orthosis is going to be utilised as an assistive device for motorically impaired stroke-patients. In the design a two-step optimisation strategy was implemented to meet all requirements for the torsion spring. The first step was to identify a promising topology for the element. In the second step, the shape was optimised based on a finite element model using two different optimisation methods in order to minimise the von Mises equivalent stresses. Four promising variants of the identified topology were extracted from these calculations, one of which was then chosen as the final design. A prototype was manufactured by a laser cutting process, which is a new procedure in the context of elastic elements for series elastic actuators. The calculation results were validated successfully by measurement of the spring properties of this prototype.

A novel protocol to evaluate ankle movements during reaching tasks using pediAnklebot

The aim of the study is to design a novel protocol to characterize the ankle movements during dorsal and plantar flexion reaching tasks using the pediAnklebot. Five healthy children were instructed to control a pointer and hit targets appearing on the monitor, by moving their ankle alternatively up and down. The protocol consisted of 60 targets, 30 up and 30 down, reachable via dorsiflexion and plantarflexion movements, respectively. Ankle angular displacements and torques were gathered by encoders and load cells embedded in the robot. Ankle motor performance was evaluated by means of kinematic, submovements and dynamic indices. Results suggest that (i) plantarflexion movements are faster and more accurate than the dorsiflexion ones, but children are able to perform with a higher level of smoothness the latter ones; (ii) children are able to stop the ankle movement more easily at the end of dorsiflexion rather than plantarflexion; (iii) the central nervous system plans plantarflexion and dorsiflexion movements with the same efficiency; (iv) children apply different torque levels during the two motor tasks and they cannot balance the inversion and eversion moments during dorsiflexion. These findings provide an important starting point for the assessment of a reference baseline of motor indices for the ankle joint.

Robotics in Lower-Limb Rehabilitation after Stroke

With the increase in the elderly, stroke has become a common disease, often leading to motor dysfunction and even permanent disability. Lower-limb rehabilitation robots can help patients to carry out reasonable and effective training to improve the motor function of paralyzed extremity. In this paper, the developments of lower-limb rehabilitation robots in the past decades are reviewed. Specifically, we provide a classification, a comparison, and a design overview of the driving modes, training paradigm, and control strategy of the lower-limb rehabilitation robots in the reviewed literature. A brief review on the gait detection technology of lower-limb rehabilitation robots is also presented. Finally, we discuss the future directions of the lower-limb rehabilitation robots.

Training to Improve Walking after Pediatric Spinal Cord Injury: A Systematic Review of Parameters and Walking Outcomes

Walking or locomotor training is often initiated following pediatric spinal cord injury (SCI). There is no synthesis of the literature on interventions targeting walking for pediatric SCI, although this would assist future clinical trials and interventions. To address this need, we completed a systematic review to summarize the who, what, when, and how of walking interventions in children with SCI. Participant characteristics, training parameters, and walking outcomes with training in pediatric SCI were identified and compared with training parameters and outcomes in adults with SCI. The PubMed, Medline, AMED, Embase, PsycInfo, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL databases were searched for studies that included participants aged 1-17 years with a SCI acquired post-birth, physical interventions, and pre- and post-training walking measures. Two researchers evaluated each study's risk of bias using a domain-based approach. Training parameters and walking outcomes were extracted. Total training duration (duration × frequency × number of weeks) was calculated. Thirteen pediatric studies (n = 43 children) were included; all but one were case series/reports. Risk of bias was high in the pediatric studies. A 2012 adult review was updated (11 studies added). As with adults, the training durations, frequencies, and modes used with the children varied; however, overground walking practice was included in 10/13 pediatric studies. Improvements in walking capacity, speed, and distance were comparable between children and adults. There was a trend for greater gains with greater total training durations. There is a paucity of high-quality research examining interventions targeting walking after pediatric SCI; however, intensive training, including practice overground, results in notable improvements.