The effects of Robotic-Assisted Locomotor training on spasticity and volitional control

What does evidence tell us about the use of gait robotic devices in patients with multiple sclerosis? A comprehensive systematic review on functional outcomes and clinical recommendations

INTRODUCTION

There is growing evidence on the efficacy of gait robotic rehabilitation in patients with multiple sclerosis (MS), but most of the studies have focused on gait parameters. Moreover, clear indications on the clinical use of robotics still lack. As part of the CICERONE Italian Consensus on Robotic Rehabilitation, the aim of this systematic review was to investigate the existing evidence concerning the role of lower limb robotic rehabilitation in improving functional recovery in patients with MS.

EVIDENCE ACQUISITION

We searched for and systematically reviewed evidence-based studies on gait robotic rehabilitation in MS, between January 1^st, 2010 and December 31^st, 2020, in the following databases: Cochrane Library, PEDro, PubMed and Google Scholar. The study quality was assessed by the 16-item assessment of multiple systematic reviews 2 (AMSTAR 2) and the 10-item PEDro scale for the other research studies.

EVIDENCE SYNTHESIS

After an accurate screening, only 17 papers were included in the review, and most of them (13 RCT) had a level II evidence. Most of the studies used the Lokomat as a grounded robotic device, two investigated the efficacy of end-effectors and two powered exoskeletons. Generally speaking, robotic treatment has beneficial effects on gait speed, endurance and balance with comparable outcomes to those of conventional treatments. However, in more severe patients (EDSS >6), robotics leads to better functional outcomes. Notably, after gait training with robotics (especially when coupled to virtual reality) MS patients also reach better non-motor outcomes, including spasticity, fatigue, pain, psychological well-being and quality of life. Unfortunately, no clinical indications emerge on the treatment protocols.

CONCLUSIONS

The present comprehensive systematic review highlights the potential beneficial role on functional outcomes of the lower limb robotic devices in people with MS. Future studies are warranted to evaluate the role of robotics not only for walking and balance outcomes, but also for other gait-training-related benefits, to identify appropriate outcome measures related to a specific subgroup of MS subjects' disease severity.

Upper limb robotic assessment: Pilot study comparing velocity dependent resistance in individuals with acquired brain injury to healthy controls

Introduction

Assessment of velocity dependent resistance (VDR) can provide insights into spasticity in individuals with upper motor neuron syndrome. This study investigates the relationship between Modified Ashworth scores and a biomechanical based representation of VDR using a rehabilitation robot. Comparisons in VDR are made for the upper limb (UL) between individuals with acquired brain injury and healthy controls for the para-sagittal plane.

Methods

The system manipulates the individual’s limb through five flexion and extension motions at increasing speeds to obtain force profiles at different velocities. An approximation of VDR is calculated and analyzed statistically against clinical scales and tested for interactions.

Results

All individuals (aged 18–65), including healthy controls exhibited VDR greater than 0 (P < 0.05). MAS scores were found to be related to VDR (P < 0.05) with an interaction found between MAS Bicep and Tricep scores (P < 0.01). Considering this interaction, evidence of differences in VDR were found between several neighboring assessment score combinations.

Conclusion

The robot can detect and quantify VDR that captures information relevant to UL spasticity. Results suggests a better categorization of VDR is possible and supports further development of rehabilitation robotics for assisting spasticity assessment.

Influences of the biofeedback content on robotic post-stroke gait rehabilitation: electromyographic vs joint torque biofeedback

Background

Add-on robot-mediated therapy has proven to be more effective than conventional therapy alone in post-stroke gait rehabilitation. Such robot-mediated interventions routinely use also visual biofeedback tools. A better understanding of biofeedback content effects when used for robotic locomotor training may improve the rehabilitation process and outcomes.

Methods

This randomized cross-over pilot trial aimed to address the possible impact of different biofeedback contents on patients’ performance and experience during Lokomat training, by comparing a novel biofeedback based on online biological electromyographic information (EMGb) versus the commercial joint torque biofeedback (Rb) in sub-acute non ambulatory patients.

12 patients were randomized into two treatment groups, A and B, based on two different biofeedback training. For both groups, study protocol consisted of 12 Lokomat sessions, 6 for each biofeedback condition, 40 min each, 3 sessions per week of frequency. All patients performed Lokomat trainings as an add-on therapy to the conventional one that was the same for both groups and consisted of 40 min per day, 5 days per week. The primary outcome was the Modified Ashworth Spasticity Scale, and secondary outcomes included clinical, neurological, mechanical, and personal experience variables collected before and after each biofeedback training.

Results

Lokomat training significantly improved gait/daily living activity independence and trunk control, nevertheless, different effects due to biofeedback content were remarked. EMGb was more effective to reduce spasticity and improve muscle force at the ankle, knee and hip joints. Robot data suggest that Rb induces more adaptation to robotic movements than EMGb. Furthermore, Rb was perceived less demanding than EMGb, even though patient motivation was higher for EMGb. Robot was perceived to be effective, easy to use, reliable and safe: acceptability was rated as very high by all patients.

Conclusions

Specific effects can be related to biofeedback content: when muscular-based information is used, a more direct effect on lower limb spasticity and muscle activity is evidenced. In a similar manner, when biofeedback treatment is based on joint torque data, a higher patient compliance effect in terms of force exerted is achieved. Subjects who underwent EMGb seemed to be more motivated than those treated with Rb.

The role of Sativex in robotic rehabilitation in individuals with multiple sclerosis: Rationale, study design, and methodology

INTRODUCTION

Currently, none of the available multiple sclerosis (MS) disease-modifying medications has been shown to stop or reverse gait disability. Recently, the nabiximols has been tested for the treatment of spasticity and walking impairment in MS. Nabiximols (trade name Sativex) is an oromucosal spray formulation containing 1:1 fixed ratio of delta-9-tetrahydrocannabinol and cannabidiol derived from cloned Cannabis sativa L. plant.

METHOD AND ANALYSIS

A single-center, prospective, parallel design, single-blind trial will be conducted at the IRCCS Neurolesi "Bonino-Pulejo" (Italy) involving MS patients affected by spasticity and undergoing a Robotic Rehabilitation training. The aim of the study is to clarify the role of Sativex coupled to a robotic neurehabilitation training in MS patients in improving motor outcomes, by means of clinical, kinematic, and neurophysiological measures. Patients will be randomly divided in 2 groups: one taking only an oral antispastic drug and the other with Sativex in add-on. After 1 month, we will evaluate the response to Sativex (responder patients' amelioration >20% at MRS score) enrolling into the study the first 20 patients with a good response to Sativex, whereas other 20 no-responder individuals will continue their antispastic drug. All the 40 subjects, were divided into 2 groups (A: Sativex + Lokomat Training, and B: other antispastic+Lokomat Training), will perform a neurorobotic-assisted gait training (each session will last at least 45 minutes, 3 times per week, for a total of 20 sessions). All the patients will undergo a complete physical and neurological examination at baseline, at the end of the robotic training (T1), and 30 days after the end of the neurorehabilitation training (T2).

Estimation of gait parameter using sonoelastography in children with cerebral palsy

We aimed to study the relationship between neuromuscular abnormalities associated with spasticity and gait impairments in spastic children with hemiplegia cerebral palsy (CP). Neuromuscular abnormalities of the tibialis anterior and medial gastrocnemius muscles of the spastic ankle were quantified using sonoelastography with two major features; i.e. entropy and histogram ratio of sonoelastography images. Gait impairments were evaluated in the gait laboratory using motion capture system, and the spatial and temporal features were extracted. The correlation analysis showed a significant relation between both the entropy and histogram ratio of sonoelastography images with walking speed and step time. The findings demonstrate that the neuromuscular abnormalities associated with spasticity may contribute to gait impairments in children with CP.

The correlation between transcranial magnetic stimulation parameters and neuromuscular properties in children with cerebral palsy

We studied the correlation between corticospinal signaling and neuromuscular properties in children with Cerebral Palsy (CP). Corticospinal signaling was evaluated using Transcranial Magnetic Stimulation (TMS). Neuromuscular properties were quantified using Hoffmann reflex (H-reflex), sonoelastography, clinical measurements, and isokinetic measures. In particular, we determined the relationship between the TMS parameters of the ankle joint and the neuromuscular features of ankle extensors and flexors as well as popular clinical measures of gait speed, endurance, balance and mobility. Seventeen CP patients and twelve healthy control subjects were evaluated. Our findings showed that the motor evoked potential (MEP) latency of TMS was significantly longer in CP than in healthy subjects. The MEP-latency was significantly correlated with the H-reflex response (r=0.71, p-value=0.04) and isokinetic features; i.e. max acceleration extension time (r=0.5, p-value=0.005), and max flexion time in the cycle (r=0.5, p-value =0.002). No significant correlation was observed between MEP-latency and clinical measurements of gait and sonoelastography of ankle muscles. The results suggest that the changes in corticospinal signaling could contribute to muscle weakness and hyperexcitability of reflexes observed in children with CP.

The Effectiveness and Safety of Exoskeletons as Assistive and Rehabilitation Devices in the Treatment of Neurologic Gait Disorders in Patients with Spinal Cord Injury: A Systematic Review

Study Design Systematic review. Clinical Questions (1) When used as an assistive device, do wearable exoskeletons improve lower extremity function or gait compared with knee-ankle-foot orthoses (KAFOs) in patients with complete or incomplete spinal cord injury? (2) When used as a rehabilitation device, do wearable exoskeletons improve lower extremity function or gait compared with other rehabilitation strategies in patients with complete or incomplete spinal cord injury? (3) When used as an assistive or rehabilitation device, are wearable exoskeletons safe compared with KAFO for assistance or other rehabilitation strategies for rehabilitation in patients with complete or incomplete spinal cord injury? Methods PubMed, Cochrane, and Embase databases and reference lists of key articles were searched from database inception to May 2, 2016, to identify studies evaluating the effectiveness of wearable exoskeletons used as assistive or rehabilitative devices in patients with incomplete or complete spinal cord injury. Results No comparison studies were found evaluating exoskeletons as an assistive device. Nine comparison studies (11 publications) evaluated the use of exoskeletons as a rehabilitative device. The 10-meter walk test velocity and Spinal Cord Independence Measure scores showed no difference in change from baseline among patients undergoing exoskeleton training compared with various comparator therapies. The remaining primary outcome measures of 6-minute walk test distance and Walking Index for Spinal Cord Injury I and II and Functional Independence Measure-Locomotor scores showed mixed results, with some studies indicating no difference in change from baseline between exoskeleton training and comparator therapies, some indicating benefit of exoskeleton over comparator therapies, and some indicating benefit of comparator therapies over exoskeleton. Conclusion There is no data to compare locomotion assistance with exoskeleton versus conventional KAFOs. There is no consistent benefit from rehabilitation using an exoskeleton versus a variety of conventional methods in patients with chronic spinal cord injury. Trials comparing later-generation exoskeletons are needed.

Can an anti-gravity treadmill improve stability of children with cerebral palsy?

We aimed to study the effects of an anti-gravity treadmill (AlterG) training on balance and postural stability in children with cerebral palsy (CP). AlterG training was performed 3 days/week for 8 weeks, with up to 45 minutes of training per session. The subject was evaluated before and after the 8-week training. The effects of training on the balance and postural stability was evaluated based on the Romberg test that was performed by using a posturography device. The parameters quantifying Center-of-Pressure (CoP) were calculated using different analytical approaches including power spectral density and principal components analyses. All of the key parameters including the Stabilogram, the Fast Fourier Transform (FFT) Energy, the Eigenvectors, and the Eigenvalues of CoP were modified between 14%-84%. The results indicated that the balance features were improved substantially after training. The clinical implication is that the AlterG has the potential to effectively improve postural stability in children with cerebral palsy.

Feasibility study on a perceived fatigue prediction dependent power control for an electrically assisted bicycle

Several types of electric motor assists have been developed, as a result, it is important to control muscular fatigue on-site in terms of health promotion and motor rehabilitation. Predicting the perceived fatigue by several biosignal-related variables with the multiple regression model and polynomial approximation, we try to propose a self control design for the electrically assisted bicycle (EAB). We also determine the meaningful muscles during pedaling by muscle synergies in relation to the motion maturity. In field experiments, prediction of ongoing perceived physical fatigue could have the potential of suitable control of EAB.

Effectiveness of robot-assisted therapy on ankle rehabilitation--a systematic review

OBJECTIVE

The aim of this study was to provide a systematic review of studies that investigated the effectiveness of robot-assisted therapy on ankle motor and function recovery from musculoskeletal or neurologic ankle injuries.

METHODS

Thirteen electronic databases of articles published from January, 1980 to June, 2012 were searched using keywords 'ankle*', 'robot*', 'rehabilitat*' or 'treat*' and a free search in Google Scholar based on effects of ankle rehabilitation robots was also conducted. References listed in relevant publications were further screened. Eventually, twenty-nine articles were selected for review and they focused on effects of robot-assisted ankle rehabilitation.

RESULTS

Twenty-nine studies met the inclusion criteria and a total of 164 patients and 24 healthy subjects participated in these trials. Ankle performance and gait function were the main outcome measures used to assess the therapeutic effects of robot-assisted ankle rehabilitation. The protocols and therapy treatments were varied, which made comparison among different studies difficult or impossible. Few comparative trials were conducted among different devices or control strategies. Moreover, the majority of study designs met levels of evidence that were no higher than American Academy for Cerebral Palsy (CP) and Developmental Medicine (AACPDM) level IV. Only one study used a Randomized Control Trial (RCT) approach with the evidence level being II.

CONCLUSION

All the selected studies showed improvements in terms of ankle performance or gait function after a period of robot-assisted ankle rehabilitation training. The most effective robot-assisted intervention cannot be determined due to the lack of universal evaluation criteria for various devices and control strategies. Future research into the effects of robot-assisted ankle rehabilitation should be carried out based on universal evaluation criteria, which could determine the most effective method of intervention. It is also essential to conduct trials to analyse the differences among different devices or control strategies.