Effects of Assist-As-Needed Upper Extremity Robotic Therapy after Incomplete Spinal Cord Injury: A Parallel-Group Controlled Trial

Assessing the Effect of Cervical Transcutaneous Spinal Stimulation With an Upper Limb Robotic Exoskeleton and Surface Electromyography

Transcutaneous spinal stimulation (TSS) is a promising rehabilitative intervention to restore motor function and coordination for individuals with spinal cord injury (SCI). The effects of TSS are most commonly assessed by evaluating muscle response to stimulation using surface electromyography (sEMG). Given the increasing use of robotic devices to deliver therapy and the emerging potential of hybrid rehabilitation interventions that combine neuromodulation with robotic devices, there is an opportunity to leverage the on-board sensors of the robots to measure kinematic and torque changes of joints in the presence of stimulation. This paper explores the potential for robotic assessment of the effects of TSS delivered to the cervical spinal cord. We used a four degree-of-freedom exoskeleton to measure the torque response of upper limb (UL) joints during stimulation, while simultaneously recording sEMG. We analyzed joint torque and electromyography data generated during TSS delivered over individual sites of the cervical spinal cord in neurologically intact participants. We show that site-specific effects of TSS are manifested not only by modulation of the amplitude of spinally evoked motor potentials in UL muscles, but also by changes in torque generated by individual UL joints. We observed preferential resultant action of proximal muscles and joints with stimulation at the rostral site, and of proximal joints with rostral-lateral stimulation. Robotic assessment can be used to measure the effects of TSS, and could be integrated into complex control algorithms that govern the behavior of hybrid neuromodulation-robotic systems.

Essential training variables of arm-hand training in people with cervical spinal cord injury: a systematic review

OBJECTIVE

To identify and evaluate 3 training variables of motor training programmes involving people with a cervical spinal cord injury: i.e. motor training strategies, therapy dosage, and persons' motivation for arm-hand functioning in subacute and chronic phases.

METHODS

PubMed, Cochrane, CINAHL, EMBASE, and DARE databases were searched for active arm-hand motor training programmes. Two independent reviewers assessed methodological quality. Pre-post effect sizes were calculated using Hedge's g, and mean effect sizes were calculated to compare outcomes on the International Classification of Functioning, Disability, and Health levels of function and activity.

RESULTS

Twelve training programmes integrated mainly skill training alone or combined with strength and/or endurance training. Task-oriented training components included: multiple movement planes, functional movements, clear functional goals, and bimanual practice. Training duration of 8 weeks was common. Quantitative analyses of 8 training programmes showed an overall small effect (0.34) on function level and an overall moderate effect (0.55) on activity level. In depth-analysis of activity level showed moderate effects of skill training only (0.55) or combined with strength and endurance training (0.53). Moderate effects (0.53-0.60) were found for integrating functional movements, clear functional goals, real-life object manipulation, multiple movement planes, total skill practice, context-specific environment, exercise variety, and bimanual practice. Training of minimum 8 weeks showed a moderate effect (0.60-0.69).

CONCLUSION

Based on limited studies, arm-hand functioning aiming to improve activity level can be improved using skill training with at least 8 task-oriented training components, additional strength and endurance training, with a minimum training duration of 8 weeks.

Computer-assisted robotic device for upper limb interventions for a patient with an incomplete cervical level spinal cord injury

A man in his 50s with an incomplete cervical spinal cord injury underwent a 3-week occupational therapy programme using a computer-assisted robotic device for the upper limbs (Diego) in an acute care spinal injury unit. The patient and their partner reported their experience. Range of motion (ROM), muscle strength, pain, fatigue, independence and occupational performance are reported. Improvements occurred in upper limb ROM (shoulder and elbow), muscle strength (right elbow extensors), fatigue and functional status. Whether the results in this patient with the Diego were the same or better than standard care could not be determined. Preliminary findings suggest that the Diego was feasible for rehabilitation in an acute setting in our patient. However, it may not be suitable for all patients and a large comparative study with other therapies is needed. A limitation in the use of the Diego relates to the initial cost of the device ($A150 000).

Motor Control Changes after Utilizing Upper Extremity Myoelectric Powered Wearable Orthotics in Persons with Acute SCI

Following spinal cord injury (SCI), upper extremity (UE) weakness may impede one's ability to carry out activities of daily living (ADLs). Such a limitation drastically lowers a person's level of independence. Additionally, therapy and the field of assistive technology continue to place a strong premium on the restoration of UE motor function in patients with SCI. The main objective of this study was to assess the benefits of an UE myoelectric-powered wearable orthosis (MPWO) produced by MyoMo, Inc. (Boston, MA) on improving UE motor function in order to enhance ADLs and quality of life in individuals with subacute SCI. A 43-year-old man with subacute incomplete SCI (iSCI), American Spinal Injury Association (ASIA) Impairment Scale (AIS) C grade received 18 sessions (over a period of six weeks) of UE mobility therapy utilizing the MPWO. The MPWO was used to enhance active range of motion (AROM) of the hand and elbow, and associated muscle activations. After training with the MPWO, hand and elbow AROM and muscle activations were enhanced. These preliminary findings imply that UE-MPWO device-assisted rehabilitation may increase participants' UE activities, leading to improved function.Clinical Relevance- These preliminary findings from a person with iSCI in the subacute phase indicate that training with UE-MPWO assistive devices may enhance UE use during ADLs for people with muscle weakness but still having some residual voluntary muscle activation ability.

Hybrid FES-exoskeleton control: Using MPC to distribute actuation for elbow and wrist movements

Introduction

Individuals who have suffered a cervical spinal cord injury prioritize the recovery of upper limb function for completing activities of daily living. Hybrid FES-exoskeleton systems have the potential to assist this population by providing a portable, powered, and wearable device; however, realization of this combination of technologies has been challenging. In particular, it has been difficult to show generalizability across motions, and to define optimal distribution of actuation, given the complex nature of the combined dynamic system.

Methods

In this paper, we present a hybrid controller using a model predictive control (MPC) formulation that combines the actuation of both an exoskeleton and an FES system. The MPC cost function is designed to distribute actuation on a single degree of freedom to favor FES control effort, reducing exoskeleton power consumption, while ensuring smooth movements along different trajectories. Our controller was tested with nine able-bodied participants using FES surface stimulation paired with an upper limb powered exoskeleton. The hybrid controller was compared to an exoskeleton alone controller, and we measured trajectory error and torque while moving the participant through two elbow flexion/extension trajectories, and separately through two wrist flexion/extension trajectories.

Results

The MPC-based hybrid controller showed a reduction in sum of squared torques by an average of 48.7 and 57.9% on the elbow flexion/extension and wrist flexion/extension joints respectively, with only small differences in tracking accuracy compared to the exoskeleton alone.

Discussion

To realize practical implementation of hybrid FES-exoskeleton systems, the control strategy requires translation to multi-DOF movements, achieving more consistent improvement across participants, and balancing control to more fully leverage the muscles' capabilities.

Upper Limb Robotic Rehabilitation for Patients with Cervical Spinal Cord Injury: A Comprehensive Review

The upper extremities limitation represents one of the essential functional impairments in patients with cervical spinal cord injury. Electromechanics assisted devices and robots are increasingly used in neurorehabilitation to help functional improvement in patients with neurological diseases. This review aimed to systematically report the evidence-based, state-of-art on clinical applications and robotic-assisted arm training (RAT) in motor and functional recovery in subjects affected by cervical spinal cord injury. The present study has been carried out within the framework of the Italian Consensus Conference on "Rehabilitation assisted by robotic and electromechanical devices for persons with disability of neurological origin" (CICERONE). PubMed/MEDLINE, Cochrane Library, and Physiotherapy Evidence Database (PEDro) databases were systematically searched from inception to September 2021. The 10-item PEDro scale assessed the study quality for the RCT and the AMSTAR-2 for the systematic review. Two different authors rated the studies included in this review. If consensus was not achieved after discussion, a third reviewer was interrogated. The five-item Oxford CEBM scale was used to rate the level of evidence. A total of 11 studies were included. The selected studies were: two systematic reviews, two RCTs, one parallel-group controlled trial, one longitudinal intervention study and five case series. One RCT was scored as a high-quality study, while the systematic review was of low quality. RAT was reported as feasible and safe. Initial positive effects of RAT were found for arm function and quality of movement in addition to conventional therapy. The high clinical heterogeneity of treatment programs and the variety of robot devices could severely affect the generalizability of the study results. Therefore, future studies are warranted to standardize the type of intervention and evaluate the role of robotic-assisted training in subjects affected by cervical spinal cord injury.

The Rehabilitation Effects of Myoelectric Powered Wearable Orthotics on Improving Upper Extremity Function in Persons with SCI

Upper extremity (UE) weakness and/or paralysis following spinal cord injury (SCI) can lead to a limited capacity to perform activities of daily living (ADL). Such disability significantly reduces an individual's level of independence. Further, restoration of UE motor function in people with SCI remains a high priority in rehabilitation and the field of assistive technology. The overall goal of this study was to evaluate the effects of a myoelectric-powered wearable orthosis (MPWO) manufactured by MyoMo, Inc. (Boston, MA) for UE movement assistance on ameliorating UE motor function in order to improve ADL and quality of life in people with SCI. Two male participants with chronic incomplete SCI (iSCI), a 75- and a 31-year-old with AIS D and B, respectively, underwent 18 sessions (over 6 weeks) of UE movement rehabilitation using the MPWO. Handgrip strength, active range of motion (AROM) of the hand, response time to initiate a movement, and muscles activations were examined before and after the rehabilitation training using the MPWO. The response time to initiate UE movements decreased, and handgrip strength and AROM improved after training with the MPWO. These preliminary data suggest that rehabilitation with the use of the UE-MPWO device could enhance the participants' UE activities that led to improved function.Clinical Relevance- These preliminary results from two individuals with iSCI suggest that training with UE-MPWO assistive devices may improve UE utilization during ADL for individuals with muscle weakness or paralysis but still possessing residual voluntary muscle activation capabilities.

Upper Extremity Functional Improvements in Persons with SCI Resulted from Daily Utilization of Myoelectric Powered Wearable Orthotics

Spinal cord injury (SCI) is a medically complex and life-disrupting condition. It is estimated that 17,700 new traumatic SCI cases are reported each year in the United States. Approximately half of those cases, involves paralysis, sensory loss, and impaired motor control in the upper extremity (UE) and lower extremities. Such impairments could affect the person's independence as well as their family members and caregiver. The limitation at the UE can significantly limit the general activities of daily living (ADL). The purpose of this paper is to determine the daily utilization effects on changing the handgrip AROM and handgrip forces before and after providing upper extremity in-clinic rehabilitation along with at-home utilization using an UE myoelectric powered wearable orthosis (UE-MPWO) in a person with incomplete spinal cord injury (iSCI). This device helps restore function to the weakened or paralyzed UE muscles. We demonstrate that the handgrip AROM and handgrip force improved after 6-weeks of training with the UE-MPWO. The overall goal of this study was to evaluate the effects of UE-MPWO (MyoPro) when utilized for in-clinic rehabilitation combined with at-home daily use in improving UE movement and function of people with iSCI.Clinical Relevance- The results of in-clinic rehabilitation combined with at-home daily utilization suggest that this UE-MPWO may improve UE function. The examined UE-MPWO could represent a relatively good example as a rehabilitation and assistive tool for persons with iSCI.

Robotic assistive and rehabilitation devices leading to motor recovery in upper limb: a systematic review

PURPOSE

Stroke, spinal cord injury and other neuromuscular disorders lead to impairments in the human body. Upper limb impairments, especially hand impairments affect activities of daily living (ADL) and reduce the quality of life. The purpose of this review is to compare and evaluate the available robotic rehabilitation and assistive devices that can lead to motor recovery or maintain the current motor functional level.

METHODS

A systematic review was conducted of the literature published in the years from 2016-2021, to focus on the most recent rehabilitation and assistive devices available in the market or research environments.

RESULTS

A total of 230 studies published between 2016 and 2021 were identified from various databases. 107 were excluded with various reasons. Twenty-eight studies were taken into detailed review, to determine the efficacy of robotic devices in improving upper limb impairments or maintaining the current level from getting worse.

CONCLUSION

It was concluded that with a good strategy and treatment plan; appropriate and regular use of these robotic rehabilitation and assistive devices do lead to improvements in current conditions of most of the subjects and prolonged use may lead to motor recovery.Implications for RehabilitationStroke, accidents, spinal cord injuries and other neuromuscular disorders lead to impairments. Upper limb impairments have a tremendous adverse affect on ADL and reduces quality of life drastically.Advancement in technology has led to the designing of many robotic assistive and rehabilitation devices to assist in motor recovery or aid in ADL.This review analyses different available devices for rehabilitation and assistance and points out that use of these devices in time does help in motor recovery. Most of the studies reviewed showed improvements for the user.Future devices should be more portable and easier to use from home.

Assistive robotic arm: Evaluation of the performance of intelligent algorithms

People with upper body disabilities may be limited in their activities of daily living. Robotic arms, such as JACO, are assistive devices that could improve their abilities, independent living, and social participation. However, performing complex tasks with JACO can be time-consuming or tedious. Therefore, some advanced functionalities have been developed to enhance the performance of users. The main objective of this study is to evaluate the performance, in terms of ease of use, task completion time, and participants' perception of usability, of three new algorithms applied to the JACO robotic arm: (1) predefined position, (2) fluidity filter, and (3) drinking mode. The secondary objective is to evaluate differences in performance variables between proportional and non-proportional control modes. Fourteen participants with upper body disabilities completed various tasks with and without these functionalities. Using JACO with the algorithms led to a significant decrease of up to 72% in task completion time and improvements of 2.3 and 2.9 on a 7-point Likert scale for perceived ease of use and usability, respectively. There was no significant difference between control modes. Our results demonstrate that algorithms could produce significant improvements in performing daily living activities.

van Asseldonk EH. Automatic versus manual tuning of robot-assisted gait training in people with neurological disorders

BACKGROUND

In clinical practice, therapists choose the amount of assistance for robot-assisted training. This can result in outcomes that are influenced by subjective decisions and tuning of training parameters can be time-consuming. Therefore, various algorithms to automatically tune the assistance have been developed. However, the assistance applied by these algorithms has not been directly compared to manually-tuned assistance yet. In this study, we focused on subtask-based assistance and compared automatically-tuned (AT) robotic assistance with manually-tuned (MT) robotic assistance.

METHODS

Ten people with neurological disorders (six stroke, four spinal cord injury) walked in the LOPES II gait trainer with AT and MT assistance. In both cases, assistance was adjusted separately for various subtasks of walking (in this study defined as control of: weight shift, lateral foot placement, trailing and leading limb angle, prepositioning, stability during stance, foot clearance). For the MT approach, robotic assistance was tuned by an experienced therapist and for the AT approach an algorithm that adjusted the assistance based on performances for the different subtasks was used. Time needed to tune the assistance, assistance levels and deviations from reference trajectories were compared between both approaches. In addition, participants evaluated safety, comfort, effect and amount of assistance for the AT and MT approach.

RESULTS

For the AT algorithm, stable assistance levels were reached quicker than for the MT approach. Considerable differences in the assistance per subtask provided by the two approaches were found. The amount of assistance was more often higher for the MT approach than for the AT approach. Despite this, the largest deviations from the reference trajectories were found for the MT algorithm. Participants did not clearly prefer one approach over the other regarding safety, comfort, effect and amount of assistance.

CONCLUSION

Automatic tuning had the following advantages compared to manual tuning: quicker tuning of the assistance, lower assistance levels, separate tuning of each subtask and good performance for all subtasks. Future clinical trials need to show whether these apparent advantages result in better clinical outcomes.

Effects of Combined Upper Limb Robotic Therapy in Patients With Tetraplegic Spinal Cord Injury

OBJECTIVE

To confirm the effects of combined upper limb robotic therapy (RT) as compared to conventional occupational therapy (OT) in tetraplegic spinal cord injury (SCI) patients and to suggest the optimized treatment guidelines of combined upper limb RT.

METHODS

After subject recruitment and screening for eligibility, the baseline evaluation for outcome measures were performed. We evaluated the Graded and Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP), the American Spinal Injury Association upper extremity motor score, grip and pinch strength, and the Spinal Cord Independence Measurement III (SCIM-III). In this study, the pre-tested participants were divided randomly into the RT and OT group. The utilized interventions included combined upper limb RT using ArmeoPower and Amadeo (RT group), or conventional OT (OT group) in addition to daily inpatient rehabilitation program. The participants underwent 40 minutes×3 sessions×5 weeks of interventions.

RESULTS

A total of 30 tetraplegic SCI patients completed entire study program. After 5 weeks of intervention, both groups demonstrated increases in GRASSP-strength and SCIM-III. The manual muscle test scores of elbow flexion, elbow extension, 2-5th metacarpophalangeal extension, and SCIM-III subscores of bathing-upper, dressing-upper, and grooming as well as the GRASSP-qualitative prehension score were noted to have been significantly increased in the RT group as evaluated. The OT group showed improvements in the GRASSP-quantitative prehension score and some items in grip and pinch strength. There was no significant difference between the two groups in almost all measurements except for the SCIM-III bathing-upper subscore.

CONCLUSION

Combined upper limb RT demonstrated beneficial effects on the upper limb motor function in patients with tetraplegic SCI, which were comparable with conventional OT.

Adjusting Assistance Commensurates with Patient Effort During Robot-Assisted Upper Limb Training for a Patient with Spasticity After Cervical Spinal Cord Injury: A Case Report

Limited evidence is available on optimal patient effort and degree of assistance to achieve preferable changes during robot-assisted training (RAT) for spinal cord injury (SCI) patients with spasticity. To investigate the relationship between patient effort and robotic assistance, we performed training using an electromyography-based robotic assistance device (HAL-SJ) in an SCI patient at multiple settings adjusted to patient effort. In this exploratory study, we report immediate change in muscle contraction patterns, patient effort, and spasticity in a 64-year-old man, diagnosed with cervical SCI and with American Spinal Injury Association Impairment Scale C level and C4 neurological level, who underwent RAT using HAL-SJ from post-injury day 403. Three patient effort conditions (comfortable, somewhat hard, and no-effort) by adjusting HAL-SJ’s assists were set for each training session. Degree of effort during flexion and extension exercise was assessed by visual analog scale, muscle contraction pattern by electromyography, modified Ashworth scale, and maximum elbow extension and flexion torques, immediately before and after each training session, without HAL-SJ. The amount of effort during training with the HAL-SJ at each session was evaluated. The degree of effort during training can be set to three effort conditions as we intended by adjusting HAL-SJ. In sessions other than the no-effort setting, spasticity improved, and the level of effort was reduced immediately after training. Spasticity did not decrease in the training session using HAL-SJ with the no-effort setting, but co-contraction further increased during extension after training. Extension torque was unchanged in all sessions, and flexion torque decreased in all sessions. When performing upper-limb training with HAL-SJ in this SCI patient, the level of assistance with some effort may reduce spasticity and too strong assistance may increase co-contraction. Sometimes, a patient’s effort may be seemingly unmeasurable; hence, the degree of patient effort should be further measured.

Improving short-term retention after robotic training by leveraging fixed-gain controllers

INTRODUCTION

When developing control strategies for robotic rehabilitation, it is important that end-users who train with those strategies retain what they learn. Within the current state-of-the-art, however, it remains unclear what types of robotic controllers are best suited for promoting retention. In this work, we experimentally compare short-term retention in able-bodied end-users after training with two common types of robotic control strategies: fixed- and variable-gain controllers.

METHODS

Our approach is based on recent motor learning research, where reward signals are employed to reinforce the learning process. We extend this approach to now include robotic controllers, so that participants are trained with a robotic control strategy and auditory reward-based reinforcement on tasks of different difficulty. We then explore retention after the robotic feedback is removed.

RESULTS

Overall, our results indicate that fixed-gain control strategies better stabilize able-bodied users' motor adaptation than either a no controller baseline or variable-gain strategy. When breaking these results down by task difficulty, we find that assistive and resistive fixed-gain controllers lead to better short-term retention on less challenging tasks but have opposite effects on the learning and forgetting rates.

CONCLUSIONS

This suggests that we can improve short-term retention after robotic training with consistent controllers that match the task difficulty.

Assessing User Transparency with Muscle Synergies during Exoskeleton-Assisted Movements: A Pilot Study on the LIGHTarm Device for Neurorehabilitation

Exoskeleton devices for upper limb neurorehabilitation are one of the most exploited solutions for the recovery of lost motor functions. By providing weight support, passively compensated exoskeletons allow patients to experience upper limb training. Transparency is a desirable feature of exoskeletons that describes how the device alters free movements or interferes with spontaneous muscle patterns. A pilot study on healthy subjects was conducted to evaluate the feasibility of assessing transparency in the framework of muscle synergies. For such purpose, the LIGHTarm exoskeleton prototype was used. LIGHTarm provides gravity support to the upper limb during the execution of movements in the tridimensional workspace. Surface electromyography was acquired during the execution of three daily life movements (reaching, hand-to-mouth, and hand-to-nape) in three different conditions: free movement, exoskeleton-assisted (without gravity compensation), and exoskeleton-assisted (with gravity compensation) on healthy people. Preliminary results suggest that the muscle synergy framework may provide valuable assessment of user transparency and weight support features of devices aimed at rehabilitation.

Robot-assisted upper extremity rehabilitation for cervical spinal cord injuries: a systematic scoping review

Abstact Purpose: To provide an overview of the feasibility and outcomes of robotic-assisted upper extremity training for individuals with cervical spinal cord injury (SCI), and to identify gaps in current research and articulate future research directions.

MATERIALS AND METHODS

A systematic search was conducted using Medline, Embase, PsycINFO, CCTR, CDSR, CINAHL and PubMed on June 7, 2017. Search terms included 3 themes: (1) robotics; (2) SCI; (3) upper extremity. Studies using robots for upper extremity rehabilitation among individuals with cervical SCI were included. Identified articles were independently reviewed by two researchers and compared to pre-specified criteria. Disagreements regarding article inclusion were resolved through discussion. The modified Downs and Black checklist was used to assess article quality. Participant characteristics, study and intervention details, training outcomes, robot features, study limitations and recommendations for future studies were abstracted from included articles.

RESULTS

Twelve articles (one randomized clinical trial, six case series, five case studies) met the inclusion criteria. Five robots were exoskeletons and three were end-effectors. Sample sizes ranged from 1 to 17 subjects. Articles had variable quality, with quality scores ranging from 8 to 20. Studies had a low internal validity primarily from lack of blinding or a control group. Individuals with mild-moderate impairments showed the greatest improvements on body structure/function and performance-level measures. This review is limited by the small number of articles, low-sample sizes and the diversity of devices and their associated training protocols, and outcome measures.

CONCLUSIONS

Preliminary evidence suggests robot-assisted interventions are safe, feasible and can reduce active assistance provided by therapists. Implications for rehabilitation Robot-assisted upper extremity training for individuals with cervical spinal cord injury is safe, feasible and can reduce hands-on assistance provided by therapists. Future research in robotics rehabilitation with individuals with spinal cord injury is needed to determine the optimal device and training protocol as well as effectiveness.