Feasibility and efficacy of upper limb robotic rehabilitation in a subacute cervical spinal cord injury population

Upper Extremity Functional Status in Patients with Chronic Tetraplegia in Universiti Malaya Medical Centre

Background

Persons with tetraplegia rank improved upper extremity (UE) function as the most important rehabilitation outcome because it allows them greater independence in activities of daily living (ADL). The aim of this study was to describe UE status in patients with tetraplegia using the International Spinal Cord Injury Upper Extremity Basic Data Set version 1.1 (ISCI-UE 1.1) and to determine differences in UE status between tetraplegic individuals with traumatic and non-traumatic SCIs.

Methods

This cross-sectional study was conducted among patients with tetraplegia who attended the SCI rehabilitation clinic of a tertiary hospital from September 2021 to August 2022. Both upper limbs were assessed using ISCI-UE 1.1.

Results

One hundred patients were included in this study, of whom 80 were men. The mean (SD) age of the patients was 54.30 (16.95) years old. In these patients, most SCIs (62%) were of traumatic origin. Two hundred UEs were evaluated, of which 109 showed good hand function (level 5) and 10 had the poorest hand function (level 1). Meanwhile, 130 UEs showed good shoulder function (level D) and 10 had the poorest shoulder function (level A). A statistically significant association with UE status (reach-and-grasp ability and shoulder function) was found in both the non-traumatic and traumatic SCI groups, with better hand and shoulder functions in the non-traumatic SCI group (right-hand, P = 0.004 and left hand, P = 0.001; right shoulder, P < 0.001 and left shoulder, P = 0.002).

Conclusion

ISCI-UE 1.1 is a feasible tool for documenting UE function in patients with tetraplegia. Compared with the individuals with traumatic SCI in this study, those with non-traumatic SCI demonstrated better upper extremity functionality.

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).

The Use of Kinematic Features in Evaluating Upper Limb Motor Function Learning Progress Based on Machine Learning

Evaluating progress throughout a patient's rehabilitation process helps choose effective treatment and formulate personalised and evidence-based rehabilitation interventions. The evaluation process is difficult due to the limitations of current clinical assessments. They lack the ability to reflect sensitive changes continuously throughout the rehabilitation process. Kinematic features have been extracted from individual's movement to address this problem due to their sensitivity and continuity. However, choosing appropriate kinematic features for rehabilitation evaluation has always been challenging. This paper exploits the application of kinematic features to classify movement patterns and movement qualities. 12 kinematic features were firstly extracted from a 7-segment triangle pattern of motion to monitor the learning progress with more numbers of drawing attempts. A statistical analysis was then conducted to compare the selected kinematic features with the clinically validated normalised jerk. Two supervised machine learning models were finally developed to classify movement patterns and movement qualities based on the selected kinematic features. The study was based on data recorded from 14 participants using a single position sensor. 6 kinematic features were able to reflect sensitive changes during the experiment and all kinematic features contributed to the classification tasks. Consistent with the literature, the results indicated that features based on movement velocity were the most beneficial in the classification tasks.

The effectiveness of robotic-assisted upper limb rehabilitation to improve upper limb function in patients with cervical spinal cord injuries: a systematic literature review

Background

Spinal Cord Injury (SCI) damages corticospinal tracts and descending motor pathways responsible for transmitting signals from the brain to the spinal cord, leading to temporary or permanent changes in sensation, motor function, strength, and body function below the site of injury. Cervical SCI (cSCI), which leads to tetraplegia, causes severe functional upper limb (UL) impairments that increase falls risk, limits independence, and leads to difficulties with activities of daily living (ADLs). Robotic therapy (RT) has been developed in recent decades as a new treatment approach for people with cervical spinal cord injuries (cSCI). The present review aimed to explore current available evidence and studies regarding the effectiveness of RT for individuals with cSCI in improving UL function, identify current research gaps and future research directions.

Method

This review was conducted by searching PubMed, CINAHL, Medline, Embase, and APA PsycInfo for relevant studies published from January 2010 to January 2022. Selected studies were analyzed with a focus on the patients' self-perception of limited UL function and level of independence in activities of daily living. In addition, the JBI Critical Appraisal checklist was used to assess study quality.

Results

A total of 7 articles involving 87 patients (74 males and 13 females) were included in the analysis, with four studies utilizing exoskeleton and three studies utilizing end-effector robotic devices, respectively. The quality of these studies varied between JBI Critical Appraisal scores of 4 to 8. Several studies lacked blinding and a control group which affected internal validity. Nevertheless, four out of seven studies demonstrated statistically significant improvements in outcome measurements on UL function and strength after RT.

Conclusion

This review provided mixed evidence regarding the effectiveness of RT as a promising intervention approach to improve upper limb function in participants with cSCI. Although RT was shown to be safe, feasible, and reduces active therapist time, further research on the long-term effects of UL RT is still needed. Nevertheless, this review serves as a useful reference for researchers to further develop exoskeletons with practical and plausible applications toward geriatric orthopaedics.

A 3D-printed passive exoskeleton for upper limb assistance in children with motor disorders: proof of concept through an electromyography-based assessment

The rehabilitation of children with motor disorders is mainly focused on physical interventions. Numerous studies have demonstrated the benefits of upper function using robotic exoskeletons. However, there is still a gap between research and clinical practice, owing to the cost and complexity of these devices. This study presents a proof of concept of a 3D-printed exoskeleton for the upper limb, following a design that replicates the main characteristics of other effective exoskeletons described in the literature. 3D printing enables rapid prototyping, low cost, and easy adjustment to the patient anthropometry. The 3D-printed exoskeleton, called POWERUP, assists the user’s movement by reducing the effect of gravity, thereby allowing them to perform upper limb exercises. To validate the design, this study performed an electromyography-based assessment of the assistive performance of POWERUP, focusing on the muscular response of both the biceps and triceps during elbow flexion–extension movements in 11 healthy children. The Muscle Activity Distribution (MAD) is the proposed metric for the assessment. The results show that (1) the exoskeleton correctly assists elbow flexion, and (2) the proposed metric easily identifies the exoskeleton configuration: statistically significant differences (p-value = 2.26 ⋅ 10−7 < 0.001) and a large effect size (Cohen’s d = 3.78 > 0.8) in the mean MAD value were identified for both the biceps and triceps when comparing the transparent mode (no assistance provided) with the assistive mode (anti-gravity effect). Therefore, this metric was proposed as a method for assessing the assistive performance of exoskeletons. Further research is required to determine its usefulness for both the evaluation of selective motor control (SMC) and the impact of robot-assisted therapies.

The Outcomes of Robotic Rehabilitation Assisted Devices Following Spinal Cord Injury and the Prevention of Secondary Associated Complications

Spinal cord injuries (SCIs) have major consequences on the patient’s health and life. Voluntary muscle paralysis caused by spinal cord damage affects the patient’s independence. Following SCI, an irreversible motor and sensory deficit occurs (spasticity, muscle paralysis, atrophy, pain, gait disorders, pain). This pathology has implications on the whole organism: on the osteoarticular, muscular, cardiovascular, respiratory, gastrointestinal, genito-urinary, skin, metabolic disorders, and neuro-psychic systems. The rehabilitation process for a subject having SCIs can be considered complex, since the pathophysiological mechanism and biochemical modifications occurring at the level of spinal cord are not yet fully elucidated. This review aims at evaluating the impact of robotic-assisted rehabilitation in subjects who have suffered SCI, both in terms of regaining mobility as a major dysfunction in patients with SCI, but also in terms of improving overall fitness and cardiovascular function, respiratory function, as well as the gastrointestinal system, bone density and finally the psychosocial issues, based on multiple clinical trials, and pilot studies. The researched literature in the topic revealed that in order to increase the chances of neuro-motor recovery and to obtain satisfactory results, the combination of robotic therapy, a complex recovery treatment and specific medication is one of the best decisions. Furthermore, the use of these exoskeletons facilitates better/greater autonomy for patients, as well as optimal social integration.

The Impact of Robotic Therapy on the Self-Perception of Upper Limb Function in Cervical Spinal Cord Injury: A Pilot Randomized Controlled Trial

Background: The aim of the present study was to evaluate the impact of robotic therapy in patients with cervical spinal cord injury (SCI), measured on the basis of the patients’ self-perception of limited upper limb function and level of independence in activities of daily living. Methods: Twenty-six patients with cervical SCI completed the treatment after being randomly assigned to the intervention or control group. The training consisted of 40 experimental sessions 1 h in duration, ideally occurring 5 days/week for 8 weeks. In addition to the conventional daily therapy (30 min), the control group received another 30 min of conventional therapy, whereas the intervention group received 30 min of robotic therapy. Patients were evaluated by means of the Capabilities of Upper Extremity Questionnaire (CUE) and Spinal Cord Independence Measure (SCIM) clinical scales. Results: The improvement in the feeding item of SCIM was significantly higher in the intervention group than in the control group after the treatment (2.00 (0.91) vs. 1.18 (0.89), p = 0.03). The correlation between the CUE and SCIM scales was higher at the ending than at baseline for both groups. Conclusions: Although both groups improved, the clinical relevance related to the changes observed for both assessments was slightly higher in the intervention group than in the control group.

Preliminary evaluation of the reliability and validity of the 3D printed Toronto Rehabilitation Institute-Hand Function Test in individuals with spinal cord injury

OBJECTIVE

The study objectives were to evaluate the inter-rater and intra-rater reliability; and criterion and construct validity of the 3D printed Toronto Rehabilitation Institute -Hand Function Test (3D TRI-HFT) in individuals with spinal cord injury (SCI).

DESIGN

Observational study.

SETTING

Inpatient Rehabilitation Hospital.

PARTICIPANTS

Four individuals with subacute and three individuals with chronic SCI.

INTERVENTIONS

Reliability and validity of the 3D TRI-HFT was assessed within two interventional studies.

OUTCOME MEASURES

Participants performed the 3D TRI-HFT, Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP), Functional Independence Measure (FIM) and the Spinal Cord Independence Measure (SCIM) at baseline, after 20 and 40 sessions of therapy and at six month follow-up from baseline. 3D TRI-HFT assessments were graded at the time of performance and re-graded from the video recordings for purpose of reliability testing. Validity testing was done by comparing the scores on 3D TRI-HFT with the scores on the GRASSP, and the FIM and SCIM self care sub-scores.

RESULTS

The 3D TRI-HFT had high intra-rater and inter-rater reliability in sub-acute and chronic SCI with ICC values exceeding 0.99. Moderate to strong correlations were found between 3D TRI-HFT object manipulation scores and the FIM and SCIM self care sub-scores, with r values in the range of 0.7-0.8. Strong correlations were found between the various components of GRASSP and the 3D TRI-HFT, with r values exceeding 0.9.

CONCLUSIONS

The 3D TRI-HFT is a reliable and valid measure to assess unilateral hand gross motor function in individuals with SCI.

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.

Single limb cable driven wearable robotic device for upper extremity movement support after traumatic brain injury

Introduction

Recently, soft exosuits have been proposed for upper limb movement assistance, most supporting single joint movements. We describe the design of a portable wearable robotic device (WRD), “Armstrong,” able to support three degrees-of-freedom of arm movements, and report on its feasibility for movement support of individuals with hemiparesis after traumatic brain injury (TBI).

Methods

We introduce Armstrong and report on a pilot evaluation with two male individuals post-TBI (T1 and T2) and two healthy individuals. Testing involved elbow flexion/extension with and without robotic-assisted shoulder stabilization; shoulder abduction with and without robotic-assisted elbow stabilization; and assisted shoulder abduction and flexion. Outcome measures included range of motion and root mean square trajectory and velocity errors.

Results

TBI subjects performed active, passive, hybrid and active assistive movements with Armstrong. Subjects showed improvements in movement trajectory and velocity. T1 benefited from hybrid, active, and assistive modes due to upper extremity weakness and muscle tone. T2 benefited from hybrid and assistive modes due to impaired coordination. Healthy subjects performed isolated movements of shoulder and elbow with minimal trajectory and velocity errors.

Conclusions

This study demonstrates the safety and feasibility of Armstrong for upper extremity movement assistance for individuals with TBI, with therapist supervision.

Dual motor cortex and spinal cord neuromodulation improves rehabilitation efficacy and restores skilled locomotor function in a rat cervical contusion injury model

Motor recovery after spinal cord injury is limited due to sparse descending pathway axons caudal to the injury. Rehabilitation is the primary treatment for paralysis in humans with SCI, but only produces modest functional recovery. Here, we determined if dual epidural motor cortex (M1) intermittent theta burst stimulation (iTBS) and cathodal transcutaneous spinal direct stimulation (tsDCS) enhances the efficacy of rehabilitation in improving motor function after cervical SCI. iTBS produces CST axon sprouting and tsDCS enhances M1-evoked spinal activity and muscle contractions after SCI. Rats were trained to perform the horizontal ladder task. Animals received a moderate midline C4 contusion, producing bilateral forelimb impairments. After 2 weeks, animals either received 10 days of iTBS+tsDCS or no stimulation; subsequently, all animals received 6 weeks of daily rehabilitation on the horizontal ladder task. Lesion size was not different in the two animal groups. Rehabilitation alone improved performance by a 22% reduction in skilled locomotion error rate, whereas stimulation+rehabilitation was markedly more effective (52%), and restored error rate to pre-injury levels. Stimulation+rehabilitation significantly increased CST axon length caudal to the injury and the amount of ventral horn label was positively correlated with functional improvement. The stimulation+rehabilitation group had significantly less proprioceptive afferent terminal labelling in the intermediate zone and fewer synapses on motoneurons . Afferent fiber terminal labeling was negatively correlated with motor recovery. Thus, the dual neuromodulation protocol promotes adaptive plasticity in corticospinal and proprioceptive afferents networks after contusion SCI, leading to enhanced rehabilitation efficacy and recovery of skilled locomotion.

Portable Motion-Analysis Device for Upper-Limb Research, Assessment, and Rehabilitation in Non-Laboratory Settings

This study presents the design and feasibility testing of an interactive portable motion-analysis device for the assessment of upper-limb motor functions in clinical and home settings. The device engages subjects to perform tasks that imitate activities of daily living, e.g. drinking from a cup and moving other complex objects. Sitting at a magnetic table subjects hold a 3D printed cup with an adjustable magnet and move this cup on the table to targets that can be drawn on the table surface. A ball rolling inside the cup can enhance the task challenge by introducing additional dynamics. A single video camera with a portable computer tracks real-time kinematics of the cup and the rolling ball using a custom-developed, color-based computer-vision algorithm. Preliminary verification with marker-based 3D-motion capture demonstrated that the device produces accurate kinematic measurements. Based on the real-time 2D cup coordinates, audio-visual feedback about performance can be delivered to increase motivation. The feasibility of using this device in clinical diagnostics is demonstrated on 2 neurotypical children and also 3 children with upper-extremity impairments in the hospital, where conventional motion-analysis systems are difficult to use. The device meets key needs for clinical practice: 1) a portable solution for quantitative motor assessment for upper-limb movement disorders at non-laboratory clinical settings, 2) a low-cost rehabilitation device that can increase the volume of in-home physical therapy, and 3) the device affords testing and training a variety of motor tasks inspired by daily challenges to enhance self-confidence to participate in day-to-day activities.

Design of Shape Memory Alloy-Based Soft Wearable Robot for Assisting Wrist Motion

In this paper, we propose a shape memory alloy (SMA)-based wearable robot that assists the wrist motion for patients who have difficulties in manipulating the lower arm. Since SMA shows high contraction strain when it is designed as a form of coil spring shape, the proposed muscle-like actuator was designed after optimizing the spring parameters. The fabricated actuator shows a maximum force of 10 N and a maximum contraction ratio of 40%. The SMA-based wearable robot, named soft wrist assist (SWA), assists 2 degrees of freedom (DOF) wrist motions. In addition, the robot is totally flexible and weighs 151g for the wearable parts. A maximum torque of 1.32 Nm was measured for wrist flexion, and a torque of larger than 0.5 Nm was measured for the other motions. The robot showed the average range of motion (ROM) with 33.8, 30.4, 15.4, and 21.4 degrees for flexion, extension, ulnar, and radial deviation, respectively. Thanks to the soft feature of the SWA, time cost for wearing the device is shorter than 2 min as was also the case for patients when putting it on by themselves. From the experimental results, the SWA is expected to support wrist motion for diverse activities of daily living (ADL) routinely for patients.

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.

Robotics in Health Care: Perspectives of Robot-Aided Interventions in Clinical Practice for Rehabilitation of Upper Limbs

Robot-aided systems to support the physical rehabilitation of individuals with neurological impairment is one of the fields that has been widely developed in the last few decades. However, the adoption of these systems in clinical practice remains limited. In order to better understanding the causes of this limitation, a systematic review of robot-based systems focused on upper extremity rehabilitation is presented in this paper. A systematic search and review of related articles in the literature were conducted. The chosen works were analyzed according to the type of device, the data analysis capability, the therapy method, the human–robot interaction, the safety strategies, and the focus of treatment. As a conclusion, self-adaptation for personalizing the treatments, safeguarding and enhancing of patient–robot interaction towards training essential factors of movement generation into the same paradigm, or the use of lifelike environments in fully-immersive virtual reality for increasing the assimilation of motor gains could be relevant factors to develop more accepted robot-aided systems in clinical practice.

Robot-Assisted Therapy in Upper Extremity Hemiparesis: Overview of an Evidence-Based Approach

Robot-mediated therapy is an innovative form of rehabilitation that enables highly repetitive, intensive, adaptive, and quantifiable physical training. It has been increasingly used to restore loss of motor function, mainly in stroke survivors suffering from an upper limb paresis. Multiple studies collated in a growing number of review articles showed the positive effects on motor impairment, less clearly on functional limitations. After describing the current status of robotic therapy after upper limb paresis due to stroke, this overview addresses basic principles related to robotic therapy applied to upper limb paresis. We demonstrate how this innovation is an evidence-based approach in that it meets both the improved clinical and more fundamental knowledge-base about regaining effective motor function after stroke and the need of more objective, flexible and controlled therapeutic paradigms.

A suite of automated tools to quantify hand and wrist motor function after cervical spinal cord injury

Background

Cervical spinal cord injury (cSCI) often causes chronic upper extremity disability. Reliable measurement of arm function is critical for development of therapies to improve recovery after cSCI. In this study, we report a suite of automated rehabilitative tools to allow simple, quantitative assessment of hand and wrist motor function.

Methods

We measured range of motion and force production using these devices in cSCI participants with a range of upper limb disability and in neurologically intact participants at two time points separated by approximately 4 months. Additionally, we determined whether measures collected with the rehabilitative tools correlated with standard upper limb assessments, including the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) and the Jebsen Hand Function Test (JHFT).

Results

We find that the rehabilitative devices are useful to provide assessment of upper limb function in physical units over time in SCI participants and are well-correlated with standard assessments.

Conclusions

These results indicate that these tools represent a reliable system for longitudinal evaluation of upper extremity function after cSCI and may provide a framework to assess the efficacy of strategies aimed at improving recovery of upper limb function.

Electronic supplementary material

The online version of this article (10.1186/s12984-019-0518-8) contains supplementary material, which is available to authorized users.

A single-subject study of robotic upper limb training in the subacute phase for four persons with cervical spinal cord injury

Study design

Single-subject design, standard training ("B") compared with Robotic training ("C").

Objectives

To explore the impact of robotic training on upper limb function, activities of daily living (ADL) and training experience in subacute tetraplegic inpatients.

Setting

Inpatient subacute Norwegian spinal cord injury (SCI) unit.

Methods

Four participants (C4-7, AIS A-C) completed 11 sessions of robotic training using a passive robotic exoskeleton (Armeo Spring®). Descriptive statistics and visual analyses were used for comparing standard occupational therapy and robotic training. Outcome measures included the Spinal Cord Independence Measure (SCIM-III), the Graded Redefined Assessment of Strength Sensibility and Prehension (GRASSP), and a questionnaire.

Results

All of the participants exhibited an increase in assessments of upper limb function (GRASSP-total) right side (0.4%-61.2%), and all except for one participant (-8%) showed an increase on their left side (20.9%-106.2%). Three out of four participants had improvements in ADL function SCIM-III (ranging from 5.6% to 46.7%). Results demonstrated improvements during the robotic intervention period in five out of 28 measurements. The participants enjoyed the exercise, and found it motivating and relevant to their injury (median ranged from 3.5 to 6.5 on a 0-7 scale).

Conclusions

Three out of four participants improved upper limb function and ADL independence, but the study could not confirm that improvements were due to the robotic intervention. The participants enjoyed the robotic training and found it relevant to their injury.

Reliability of Wearable-Sensor-Derived Measures of Physical Activity in Wheelchair-Dependent Spinal Cord Injured Patients

Physical activity (PA) has been shown to have a positive influence on functional recovery in patients after a spinal cord injury (SCI). Hence, it can act as a confounder in clinical intervention studies. Wearable sensors are used to quantify PA in various neurological conditions. However, there is a lack of knowledge about the inter-day reliability of PA measures. The objective of this study was to investigate the single-day reliability of various PA measures in patients with a SCI and to propose recommendations on how many days of PA measurements are required to obtain reliable results. For this, PA of 63 wheelchair-dependent patients with a SCI were measured using wearable sensors. Patients of all age ranges (49.3 ± 16.6 years) and levels of injury (from C1 to L2, ASIA A-D) were included for this study and assessed at three to four different time periods during inpatient rehabilitation (2 weeks, 1 month, 3 months, and if applicable 6 months after injury) and after in-patient rehabilitation in their home-environment (at least 6 months after injury). The metrics of interest were total activity counts, PA intensity levels, metrics of wheeling quantity and metrics of movement quality. Activity counts showed consistently high single-day reliabilities, while measures of PA intensity levels considerably varied depending on the rehabilitation progress. Single-day reliabilities of metrics of movement quantity decreased with rehabilitation progress, while metrics of movement quality increased. To achieve a mean reliability of 0.8, we found that three continuous recording days are required for out-patients, and 2 days for in-patients. Furthermore, the results show similar weekday and weekend wheeling activity for in- and out-patients. To our knowledge, this is the first study to investigate the reliability of an extended set of sensor-based measures of PA in both acute and chronic wheelchair-dependent SCI patients. The results provide recommendations for sensor-based assessments of PA in clinical SCI studies.

Effects of robot-assisted training on upper limb functional recovery during the rehabilitation of poststroke patients

BACKGROUND

The study aims to determine the effectiveness of robot-assisted training in the recovery of stroke-affected arms using an exoskeleton robot Armeo Spring.

OBJECTIVE

To identify the effect of robot training on functional recovery of the arm.

METHODS

A total of 34 stroke patients were divided into either an experimental group (EG; n= 17) or a control group (n= 17). EG was also trained to use the Armeo Spring during occupational therapy. Both groups were clinically assessed before and after treatment. Statistical comparison methods (i.e. one-tailed t-tests for differences between two independent means and the simplest test) were conducted to compare motor recovery using robot-assisted training or conventional therapy.

RESULTS

Patients assigned to the EG showed a statistically significant improvement in upper extremity motor function when compared to the CG by FIM (P< 0.05) and ACER (P< 0.05). The calculated treatment effect in the EG and CG was meaningful for shoulder and elbow kinematic parameters.

CONCLUSIONS

The findings show the benefits of robot therapy in two areas of functional recovery. Task-oriented robotic training in rehabilitation setting facilitates recovery not only of the motor function of the paretic arm but also of the cognitive abilities in stroke patients.

Getting the Best Out of Advanced Rehabilitation Technology for the Lower Limbs: Minding Motor Learning Principles

Advanced technology, including gait-training devices, is increasingly being integrated into neurorehabilitation. However, to use gait-training devices to their optimal potential, it is important that they are applied in accordance with motor learning and locomotor training principles. In this article, we outline the most important principles and explain how advanced gait-training devices are best used to improve therapy outcome.

Rehabilitation robots for the treatment of sensorimotor deficits: a neurophysiological perspective

The past decades have seen rapid and vast developments of robots for the rehabilitation of sensorimotor deficits after damage to the central nervous system (CNS). Many of these innovations were technology-driven, limiting their clinical application and impact. Yet, rehabilitation robots should be designed on the basis of neurophysiological insights underlying normal and impaired sensorimotor functions, which requires interdisciplinary collaboration and background knowledge.

Recovery of sensorimotor function after CNS damage is based on the exploitation of neuroplasticity, with a focus on the rehabilitation of movements needed for self-independence. This requires a physiological limb muscle activation that can be achieved through functional arm/hand and leg movement exercises and the activation of appropriate peripheral receptors. Such considerations have already led to the development of innovative rehabilitation robots with advanced interaction control schemes and the use of integrated sensors to continuously monitor and adapt the support to the actual state of patients, but many challenges remain. For a positive impact on outcome of function, rehabilitation approaches should be based on neurophysiological and clinical insights, keeping in mind that recovery of function is limited. Consequently, the design of rehabilitation robots requires a combination of specialized engineering and neurophysiological knowledge. When appropriately applied, robot-assisted therapy can provide a number of advantages over conventional approaches, including a standardized training environment, adaptable support and the ability to increase therapy intensity and dose, while reducing the physical burden on therapists. Rehabilitation robots are thus an ideal means to complement conventional therapy in the clinic, and bear great potential for continued therapy and assistance at home using simpler devices.

This review summarizes the evolution of the field of rehabilitation robotics, as well as the current state of clinical evidence. It highlights fundamental neurophysiological factors influencing the recovery of sensorimotor function after a stroke or spinal cord injury, and discusses their implications for the development of effective rehabilitation robots. It thus provides insights on essential neurophysiological mechanisms to be considered for a successful development and clinical inclusion of robots in rehabilitation.

Upper limb robotics applied to neurorehabilitation: An overview of clinical practice

BACKGROUND

During the last two decades, extensive interaction between clinicians and engineers has led to the development of systems that stimulate neural plasticity to optimize motor recovery after neurological lesions. This has resulted in the expansion of the field of robotics for rehabilitation. Studies in patients with stroke-related upper-limb paresis have shown that robotic rehabilitation can improve motor capacity. However, few other applications have been evaluated (e.g. tremor, peripheral nerve injuries or other neurological diseases).

PURPOSE

This paper presents an overview of the current use of upper limb robotic systems for neurorehabilitation, and highlights the rationale behind their use for the assessment and treatment of common neurological disorders.

CONCLUSIONS

Rehabilitation robots are little integrated in clinical practice, except after stroke. Although few studies have been carried out to evaluate their effectiveness, evidence from the neurosciences and indications from pilot studies suggests that upper limb robotic rehabilitation can be applied safely in various other neurological conditions. Rehabilitation robots provide an intensity, quality and dose of treatment that exceeds therapist-mediated rehabilitation. Moreover, the use of force fields, multi-sensory environments, feedback etc. renders such rehabilitation engaging and motivating. Future studies should evaluate the effectiveness of rehabilitation robots in neurological pathologies other than stroke.

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.

EMG-Based Continuous and Simultaneous Estimation of Arm Kinematics in Able-Bodied Individuals and Stroke Survivors

Among the potential biological signals for human-machine interactions (brain, nerve, and muscle signals), electromyography (EMG) widely used in clinical setting can be obtained non-invasively as motor commands to control movements. The aim of this study was to develop a model for continuous and simultaneous decoding of multi-joint dynamic arm movements based on multi-channel surface EMG signals crossing the joints, leading to application of myoelectrically controlled exoskeleton robots for upper-limb rehabilitation. Twenty subjects were recruited for this study including 10 stroke subjects and 10 able-bodied subjects. The subjects performed free arm reaching movements in the horizontal plane with an exoskeleton robot. The shoulder, elbow and wrist movements and surface EMG signals from six muscles crossing the three joints were recorded. A non-linear autoregressive exogenous (NARX) model was developed to continuously decode the shoulder, elbow and wrist movements based solely on the EMG signals. The shoulder, elbow and wrist movements were decoded accurately based only on the EMG inputs in all the subjects, with the variance accounted for (VAF) > 98% for all three joints. The proposed approach is capable of simultaneously and continuously decoding multi-joint movements of the human arm by taking into account the non-linear mappings between the muscle EMGs and joint movements, which may provide less effortful control of robotic exoskeletons for rehabilitation training of individuals with neurological disorders and arm impairment.

Rehabilitation of hand function after spinal cord injury using a novel handgrip device: a pilot study

Background

Activity-based therapy (ABT) for patients with spinal cord injury (SCI), which consists of repetitive use of muscles above and below the spinal lesion, improves locomotion and arm strength. Less data has been published regarding its effects on hand function. We sought to evaluate the effects of a weekly hand-focused therapy program using a novel handgrip device on grip strength and hand function in a SCI cohort.

Methods

Patients with SCI were enrolled in a weekly program that involved activities with the MediSens (Los Angeles, CA) handgrip. These included maximum voluntary contraction (MVC) and a tracking task that required each subject to adjust his/her grip strength according to a pattern displayed on a computer screen. For the latter, performance was measured as mean absolute accuracy (MAA). The Spinal Cord Independence Measure (SCIM) was used to measure each subject’s independence prior to and after therapy.

Results

Seventeen patients completed the program with average participation duration of 21.3 weeks. The cohort included patients with American Spinal Injury Association (ASIA) Impairment Scale (AIS) A (n = 12), AIS B (n = 1), AIS C (n = 2), and AIS D (n = 2) injuries. The average MVC for the cohort increased from 4.1 N to 21.2 N over 20 weeks, but did not reach statistical significance. The average MAA for the cohort increased from 9.01 to 21.7% at the end of the study (p = .02). The cohort’s average SCIM at the end of the study was unchanged compared to baseline.

Conclusions

A weekly handgrip-based ABT program is feasible and efficacious at increasing hand task performance in subjects with SCI.

Use of an arm weight-bearing combined with upper-limb reaching apparatus to facilitate motor paralysis recovery in an incomplete spinal cord injury patient: a single case report

[Purpose] Training using an arm weight-bearing device combined with upper-limb reaching apparatus to facilitate motor paralysis recovery, named the “Reaching Robot”, as well as Repetitive Facilitation Exercise were applied to a patient with severe impairment of the shoulder and elbow due to incomplete spinal cord injury and the effects were examined. [Subjects and Methods] A 66-year-old man with incomplete spinal cord injury participated in an upper extremity rehabilitation program involving a Reaching Robot. The program was comprised of active motor suspension, continuous low amplitude neuromuscular electrical stimulation and functional vibratory stimulation, as well as Repetitive Facilitation Exercise combined with continuous low amplitude neuromuscular electrical stimulation. This protocol used a crossover design following an A₁-B₁-A₂-B₂. “A” consisted of 2 weeks of Repetitive Facilitation Exercise, and “B” consisted of 2 weeks of Reaching Robot training. [Results] Improvements were observed after all sessions. Active range of motion for shoulder flexion improved after 2 weeks of Reaching Robot sessions only. There were no adverse events. [Conclusion] Reaching Robot training for severe paretic upper-extremity after incomplete spinal cord injury was a safe and effective treatment. Reaching Robot training may be useful for rehabilitation of paretic upper-extremity after incomplete spinal cord injury.

Using a brain-machine interface to control a hybrid upper limb exoskeleton during rehabilitation of patients with neurological conditions

Background

As a consequence of the increase of cerebro-vascular accidents, the number of people suffering from motor disabilities is raising. Exoskeletons, Functional Electrical Stimulation (FES) devices and Brain-Machine Interfaces (BMIs) could be combined for rehabilitation purposes in order to improve therapy outcomes.

Methods

In this work, a system based on a hybrid upper limb exoskeleton is used for neurological rehabilitation. Reaching movements are supported by the passive exoskeleton ArmeoSpring and FES. The movement execution is triggered by an EEG-based BMI. The BMI uses two different methods to interact with the exoskeleton from the user’s brain activity. The first method relies on motor imagery tasks classification, whilst the second one is based on movement intention detection.

Results

Three healthy users and five patients with neurological conditions participated in the experiments to verify the usability of the system. Using the BMI based on motor imagery, healthy volunteers obtained an average accuracy of 82.9 ± 14.5 %, and patients obtained an accuracy of 65.3 ± 9.0 %, with a low False Positives rate (FP) (19.2 ± 10.4 % and 15.0 ± 8.4 %, respectively). On the other hand, by using the BMI based on detecting the arm movement intention, the average accuracy was 76.7 ± 13.2 % for healthy users and 71.6 ± 15.8 % for patients, with 28.7 ± 19.9 % and 21.2 ± 13.3 % of FP rate (healthy users and patients, respectively).

Conclusions

The accuracy of the results shows that the combined use of a hybrid upper limb exoskeleton and a BMI could be used for rehabilitation therapies. The advantage of this system is that the user is an active part of the rehabilitation procedure. The next step will be to verify what are the clinical benefits for the patients using this new rehabilitation procedure.

Feasibility of an Exoskeleton-Based Interactive Video Game System for Upper Extremity Burn Contractures

BACKGROUND

Burn contractures are common and difficult to treat. Measuring continuous joint motion would inform the assessment of contracture interventions; however, it is not standard clinical practice. This study examines use of an interactive gaming system to measure continuous joint motion data.

OBJECTIVE

To assess the usability of an exoskeleton-based interactive gaming system in the rehabilitation of upper extremity burn contractures.

DESIGN

Feasibility study.

SETTING

Eight subjects with a history of burn injury and upper extremity contractures were recruited from the outpatient clinic of a regional inpatient rehabilitation facility.

METHODS

Subjects used an exoskeleton-based interactive gaming system to play 4 different video games. Continuous joint motion data were collected at the shoulder and elbow during game play.

MAIN OUTCOME MEASURES

Visual analog scale for engagement, difficulty and comfort. Angular range of motion by subject, joint, and game.

RESULTS

The study population had an age of 43 ± 16 (mean ± standard deviation) years and total body surface area burned range of 10%-90%. Subjects reported satisfactory levels of enjoyment, comfort, and difficulty. Continuous joint motion data demonstrated variable characteristics by subject, plane of motion, and game.

CONCLUSIONS

This study demonstrates the feasibility of use of an exoskeleton-based interactive gaming system in the burn population. Future studies are needed that examine the efficacy of tailoring interactive video games to the specific joint impairments of burn survivors.

Satisfaction with upper extremity surgery in individuals with tetraplegia

OBJECTIVE

To supplement the scant information available regarding the satisfaction of patients with tetraplegia following upper extremity reconstructive surgery for such individuals with spinal cord injury (SCI).

STUDY DESIGN

Retrospective study with questionnaire follow-up.

SETTING

The Danish Spinal Cord Injury Centers.

MATERIAL AND METHODS

In the initial review period, 119 upper extremity surgeries were performed on patients with tetraplegia (n = 49). Seven died and the remaining 42 were invited to complete a follow-up questionnaire with a five-level scale ranging from strongly agree to strongly disagree regarding satisfaction. Forty patients completed the questionnaire.

RESULTS

Median time from first surgery was 13 years (2-36). Sixty-five percent of the sample had a C5-C6 SCI, with 64% experiencing complete injury. Initially, 76% of the sample expressed general satisfaction with life, but only 28% of the sample reported that hand appearance improved after surgery. Interestingly, those having surgery from 1991 to 2008 reported significantly greater satisfaction (P < 0.001) and were significantly more satisfied with activities of daily living (ADL) (P < 0.001) than those having surgery between the years 1973 and 1990. In particular, gain of independence was obtained with pinch/specific hand surgery compared to triceps activation. Accordingly, the pinch/specific hand surgery group was significantly more satisfied than the triceps group on the ADL (P = 0.027), and the independence questions (P < 0.001).

CONCLUSION

Overall satisfaction with upper extremity surgery is high. It can have a positive impact on life in general, ability to perform ADL, as well as supplying an increased level of independence.

Influence of different rehabilitation therapy models on patient outcomes: hand function therapy in individuals with incomplete SCI

OBJECTIVES

The primary objective was to compare the benefits of single (COT1) versus double (COT2) dose of conventional occupational therapy (COT) in improving voluntary hand function in individuals with incomplete, sub-acute C3-C7 spinal cord injury (SCI). The secondary objective was to compare these two interventions versus functional electrical stimulation therapy plus COT (FES + COT).

DESIGN

Retrospective analysis. Setting Inpatient spinal cord rehabilitation center, Toronto.

PARTICIPANTS

Individuals with traumatic incomplete sub-acute SCI.

INTERVENTIONS

Data from Phases I and II (ClinicalTrials.gov ID NCT00221117) randomized control trials were pooled together for the purpose of this study. Participants in the COT1 group received 45 hours of therapy, the COT2 group received 80 hours of therapy, and the FES + COT group received 40 hours of COT therapy +40 hours of FES therapy.

OUTCOME MEASURES

We analyzed the functional independence measure (FIM) and the spinal cord independence measure (SCIM) self-care sub-scores. Results The mean change scores on the FIM self-care sub-score for the COT1, COT2, and FES + COT groups were 12.8, 10, and 20.1 points, respectively. Similarly, the mean change scores on the SCIM self-care sub-score for the COT1, COT2, and FES + COT groups were, 2.6, 3.16, and 10.2 points, respectively.

CONCLUSION

Increased rehabilitation intensity alone may not always be beneficial. The type of intervention plays a significant role in determining functional changes. In this instance, receiving one (COT1) or two (COT2) doses of COT resulted in similar outcomes, however, FES + COT therapy yielded much better outcomes compared to COT1 and COT2 interventions.

Feature dimensionality reduction for myoelectric pattern recognition: a comparison study of feature selection and feature projection methods

This study investigates the effect of the feature dimensionality reduction strategies on the classification of surface electromyography (EMG) signals toward developing a practical myoelectric control system. Two dimensionality reduction strategies, feature selection and feature projection, were tested on both EMG feature sets, respectively. A feature selection based myoelectric pattern recognition system was introduced to select the features by eliminating the redundant features of EMG recordings instead of directly choosing a subset of EMG channels. The Markov random field (MRF) method and a forward orthogonal search algorithm were employed to evaluate the contribution of each individual feature to the classification, respectively. Our results from 15 healthy subjects indicate that, with a feature selection analysis, independent of the type of feature set, across all subjects high overall accuracies can be achieved in classification of seven different forearm motions with a small number of top ranked original EMG features obtained from the forearm muscles (average overall classification accuracy >95% with 12 selected EMG features). Compared to various feature dimensionality reduction techniques in myoelectric pattern recognition, the proposed filter-based feature selection approach is independent of the type of classification algorithms and features, which can effectively reduce the redundant information not only across different channels, but also cross different features in the same channel. This may enable robust EMG feature dimensionality reduction without needing to change ongoing, practical use of classification algorithms, an important step toward clinical utility.

Effects of training on upper limb function after cervical spinal cord injury: a systematic review

Objective:

To summarize the evidence for the effectiveness of exercise training in promoting recovery of upper extremity function after cervical spinal cord injury.

Data sources:

Medline, Cochrane, CINAHL, EMBASE and PEDro were used to search the literature.

Review methods:

Two reviewers independently selected and summarized the included studies. Methodological quality of the selected articles was scored using the Downs and Black checklist.

Results:

A total of 16 studies were included, representing a total of 426 participants. Overall, the internal validity and reporting of the studies was fair to good, while power and external validity were poor. Interventions included exercise therapy, electrical stimulation, functional electrical stimulation, robotic training and repetitive transcranial magnetic stimulation. Most of the studies reported improvements in muscle strength, arm and hand function, activity of daily living or quality of life after intervention.

Conclusions:

Training including exercise therapy, electrical stimulation, functional electrical stimulation of the upper limb following cervical spinal cord injury leads to improvements in muscle strength, upper limb function and activity of daily living or quality of life. Further research is needed into the effects of repetitive transcranial magnetic stimulation and robotic training on upper limb function.

EMG feature assessment for myoelectric pattern recognition and channel selection: a study with incomplete spinal cord injury

Myoelectric pattern recognition with a large number of electromyogram (EMG) channels provides an approach to assessing motor control information available from the recorded muscles. In order to develop a practical myoelectric control system, a feature dependent channel reduction method was developed in this study to determine a small number of EMG channels for myoelectric pattern recognition analysis. The method selects appropriate raw EMG features for classification of different movements, using the minimum Redundancy Maximum Relevance (mRMR) and the Markov random field (MRF) methods to rank a large number of EMG features, respectively. A k-nearest neighbor (KNN) classifier was used to evaluate the performance of the selected features in terms of classification accuracy. The method was tested using 57 channels' surface EMG signals recorded from forearm and hand muscles of individuals with incomplete spinal cord injury (SCI). Our results demonstrate that appropriate selection of a small number of raw EMG features from different recording channels resulted in similar high classification accuracies as achieved by using all the EMG channels or features. Compared with the conventional sequential forward selection (SFS) method, the feature dependent method does not require repeated classifier implementation. It can effectively reduce redundant information not only cross different channels, but also cross different features in the same channel. Such hybrid feature-channel selection from a large number of EMG recording channels can reduce computational cost for implementation of a myoelectric pattern recognition based control system.

Improved motor performance in chronic spinal cord injury following upper-limb robotic training

BACKGROUND

Recovering upper-limb motor function has important implications for improving independence of patients with tetraplegia after traumatic spinal cord injury (SCI).

OBJECTIVE

To evaluate the feasibility, safety and effectiveness of robotic-assisted training of upper limb in a chronic SCI population.

METHODS

A total of 10 chronic tetraplegic SCI patients (C4 to C6 level of injury, American Spinal Injury Association Impairment Scale, A to D) participated in a 6-week wrist-robot training protocol (1 hour/day 3 times/week). The following outcome measures were recorded at baseline and after the robotic training: a) motor performance, assessed by robot-measured kinematics, b) corticospinal excitability measured by transcranial magnetic stimulation (TMS), and c) changes in clinical scales: motor strength (Upper extremity motor score), pain level (Visual Analog Scale) and spasticity (Modified Ashworth scale).

RESULTS

No adverse effects were observed during or after the robotic training. Statistically significant improvements were found in motor performance kinematics: aim (pre 1.17 ± 0.11 raduans, post 1.03 ± 0.08 raduans, p = 0.03) and smoothness of movement (pre 0.26 ± 0.03, post 0.31 ± 0.02, p = 0.03). These changes were not accompanied by changes in upper-extremity muscle strength or corticospinal excitability. No changes in pain or spasticity were found.

CONCLUSIONS

Robotic-assisted training of the upper limb over six weeks is a feasible and safe intervention that can enhance movement kinematics without negatively affecting pain or spasticity in chronic SCI. In addition, robot-assisted devices are an excellent tool to quantify motor performance (kinematics) and can be used to sensitively measure changes after a given rehabilitative intervention.

Prediction and Stratification of Upper Limb Function and Self-Care in Acute Cervical Spinal Cord Injury With the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP)

Background. There is inherent heterogeneity within individuals suffering from cervical spinal cord injury (SCI), and early prediction of upper limb function and self-care is challenging. As a result, considerable uncertainty exists regarding the prediction of functional outcome following cervical SCI within 1 year of injury. Objective. To evaluate the value of Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) in predicting upper limb function and self-care outcomes in individuals with cervical SCI. Method. A prospective longitudinal multicenter study was performed. Data from the GRASSP, the Spinal Cord Independence Measure (SCIM III), and the American Spinal Injury Association (ASIA) Impairment Scale were recorded at 1, 6, and 12 months after cervical SCI. For prediction of functional outcome at 6 and 12 months, a logistic regression model, receiver operating characteristics (ROC), and unbiased recursive partitioning conditional inference tree (URP-CTREE) were used with 8 different predictor variables. Results. Logistic regression analysis, ROC analysis, and URP-CTREE all revealed that the strength subtest within GRASSP is the strongest predictor for upper limb function and self-care outcomes. URP-CTREE provides useful information on the distribution of different outcomes in acute cervical SCI and can be used to predict cohorts with homogeneous outcomes. Conclusion. The GRASSP at 1 month can accurately predict upper limb function and self-care outcomes even in a heterogeneous group of individuals across a wide spectrum of neurological recovery. The application of URP-CTREE can reveal the distribution of outcome categories and, based on this, inform trial protocols with respect to outcomes analysis and patient stratification.

Hand contour detection in wearable camera video using an adaptive histogram region of interest

BACKGROUND

Monitoring hand function at home is needed to better evaluate the effectiveness of rehabilitation interventions. Our objective is to develop wearable computer vision systems for hand function monitoring. The specific aim of this study is to develop an algorithm that can identify hand contours in video from a wearable camera that records the user's point of view, without the need for markers.

METHODS

The two-step image processing approach for each frame consists of: (1) Detecting a hand in the image, and choosing one seed point that lies within the hand. This step is based on a priori models of skin colour. (2) Identifying the contour of the region containing the seed point. This is accomplished by adaptively determining, for each frame, the region within a colour histogram that corresponds to hand colours, and backprojecting the image using the reduced histogram.

RESULTS

In four test videos relevant to activities of daily living, the hand detector classification accuracy was 88.3%. The contour detection results were compared to manually traced contours in 97 test frames, and the median F-score was 0.86.

CONCLUSION

This algorithm will form the basis for a wearable computer-vision system that can monitor and log the interactions of the hand with its environment.

A novel myoelectric pattern recognition strategy for hand function restoration after incomplete cervical spinal cord injury

This study presents a novel myoelectric pattern recognition strategy towards restoration of hand function after incomplete cervical spinal cord Injury (SCI). High density surface electromyogram (EMG) signals comprised of 57 channels were recorded from the forearm of nine subjects with incomplete cervical SCI while they tried to perform six different hand grasp patterns. A series of pattern recognition algorithms with different EMG feature sets and classifiers were implemented to identify the intended tasks of each SCI subject. High average overall accuracies (> 97%) were achieved in classification of seven different classes (six intended hand grasp patterns plus a hand rest pattern), indicating that substantial motor control information can be extracted from partially paralyzed muscles of SCI subjects. Such information can potentially enable volitional control of assistive devices, thereby facilitating restoration of hand function. Furthermore, it was possible to maintain high levels of classification accuracy with a very limited number of electrodes selected from the high density surface EMG recordings. This demonstrates clinical feasibility and robustness in the concept of using myoelectric pattern recognition techniques toward improved function restoration for individuals with spinal injury.

Relationship Between Motor Recovery and Independence After Sensorimotor-Complete Cervical Spinal Cord Injury

Background. For therapeutics directed to the injured spinal cord, a change in neurological impairment has been proposed as a relevant acute clinical study end point. However, changes in neurological function, even if statistically significant, may not be associated with a functional impact, such as a meaningful improvement in items within the self-care subscore of the Spinal Cord Independence Measure (SCIM). Objective. The authors examined the functional significance associated with spontaneously recovering upper-extremity motor function after sensorimotor-complete cervical spinal cord injury (SCI). Methods. Using the European Multi-center Study about Spinal Cord Injury (EMSCI) data set, a retrospective analysis was undertaken of individuals with cervical sensorimotor-complete SCI (initial motor level, C4-C7). Specifically, changes in upper-extremity motor score (UEMS), motor level, and SCIM (total and self-care subscore) were assessed between approximately 1 and 48 weeks after injury (n = 74). Results. The initial motor level did not significantly influence the total UEMS recovered or number of motor levels recovered. SCIM self-care subscore recovery was significantly greater for those individuals regaining 2 motor levels compared with those recovering only 1 or no motor levels. However, the recovery in the SCIM self-care subscore was not significantly different between individuals recovering only 1 motor level and those individuals who showed no motor-level improvement. Conclusions. A 2 motor-level improvement indicates a clinically meaningful change and might be considered a primary outcome in acute and subacute interventional trials enrolling individuals with cervical sensorimotor-complete SCI.