Effects of an automated stride assistance system on walking parameters and muscular glucose metabolism in elderly adults

Safety & efficacy of a robotic hip exoskeleton on outpatient stroke rehabilitation

OBJECTIVE

The objective of this study was to analyze the safety and efficacy of using a robotic hip exoskeleton designed by Samsung Electronics Co., Ltd., Korea, called the Gait Enhancing and Motivating System-Hip (GEMS-H), in assistance mode only with the poststroke population in an outpatient-rehabilitation setting.

METHODS

Forty-one participants with an average age of 60 and average stroke latency of 6.5 years completed this prospective, single arm, interventional, longitudinal study during the COVID-19 pandemic. Significant modifications to the traditional outpatient clinical environment were made to adhere to organizational physical distancing policies as well as guidelines from the Centers for Disease Control. All participants received gait training with the GEMS-H in assistance mode for 18 training sessions over the course of 6-8 weeks. Performance-based and self-reported clinical outcomes were assessed at four time points: baseline, midpoint (after 9 training sessions), post (after 18 training sessions), and 1-month follow up. Daily step count was also collected throughout the duration of the study using an ankle-worn actigraphy device. Additionally, corticomotor excitability was measured at baseline and post for 4 bilateral lower limb muscles using transcranial magnetic stimulation.

RESULTS

By the end of the training program, the primary outcome, walking speed, improved by 0.13 m/s (p < 0.001). Secondary outcomes of walking endurance, balance, and functional gait also improved as measured by the 6-Minute Walk Test (47 m, p < 0.001), Berg Balance Scale (2.93 points, p < 0.001), and Functional Gait Assessment (1.80 points, p < 0.001). Daily step count significantly improved with and average increase of 1,750 steps per day (p < 0.001). There was a 35% increase in detectable lower limb motor evoked potentials and a significant decrease in the active motor threshold in the medial gastrocnemius (-5.7, p < 0.05) after training with the device.

CONCLUSIONS

Gait training with the GEMS-H exoskeleton showed significant improvements in walking speed, walking endurance, and balance in persons with chronic stroke. Day-to-day activity also improved as evidenced by increased daily step count. Additionally, corticomotor excitability changes suggest that training with this device may help correct interhemispheric imbalance typically seen after stroke.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov (NCT04285060).

Improvement of Functional Mobility Using a Hip-Wearable Exoskeleton Robot in Guillain-Barré Syndrome With Residual Gait Disturbance: A Case Report

Patients with Guillain-Barré syndrome (GBS) occasionally have residual gait disturbance one year after disease onset. We hypothesized that providing hip joint movement assistance can improve gait in patients with GBS and residual gait disturbance. A 78-year-old man with GBS showed improvement in gait following conventional rehabilitation and gait training using GAIT TRAINER HWA-01 (HWA-01; Honda Motor Co., Ltd., Tokyo, Japan), which is a hip-wearable exoskeleton robot. Initially, he presented with gastrointestinal symptoms, subsequently flaccid quadriplegia, and respiratory muscle paralysis. He was diagnosed with acute motor axonal neuropathy and was transferred to our hospital on day 185 after the disease onset. Seven months after rehabilitation, his walking ability plateaued. On day 382, a single-case study with ABABA design intervention, with conventional gait training in phase A and gait training using HWA-01 in phase B, was conducted. The primary outcomes included a comfortable walking speed, stride length, and cadence. Comfortable walking speed, stride length, and cadence statistically improved after gait training using HWA-01. Furthermore, improvement in exercise capacity and activities of daily living exceeded the minimal clinically important difference for the intervention. The use of the HWA-01 gait trainer potentially improves gait in patients with GBS who have residual gait disturbance.

Use of a Robotic Walking Device for Home and Community Mobility in Parkinson Disease: A Randomized Controlled Trial

BACKGROUND/PURPOSE

Gait impairments in Parkinson disease (PD) contribute to decreased quality of life. This randomized controlled trial examined immediate- and longer-term effects of a single joint robotic exoskeleton device (EXOD), the Honda Walking Assist device, on gait.

METHODS

Participants (n = 45) with PD (Hoehn and Yahr stages 1-3) were randomized to a robotic-assisted gait training (RAGT) group (n = 23) or control (CON) group (n = 22). The RAGT group was tested with and without the EXOD at baseline and then received supervised in-home and community training with the EXOD twice weekly for 8 weeks. The CON group received no interventions. Outcome measures included gait speed (primary), gait endurance (6-minute walk test), perceived ease of walking, and questionnaires and logs assessing performance of daily activities, freezing of gait, and daily activity levels.

RESULTS

Forty participants completed the study. No significant immediate impact of EXOD usage on participants' gait measures was found. Differences in gait speed and secondary outcome measures postintervention were not significantly different between the RAGT and CON groups. Participants with greater disease severity (worse baseline motor scores) had greater improvements in stride length during unassisted walking after the intervention than those with lower severity (mean difference: 3.22, 95% confidence interval: 0.05-6.40; P = 0.04).

DISCUSSION AND CONCLUSIONS

All RAGT participants could use the EXOD safely. The RAGT treatment used in this mostly low impairment population of people with PD may be ineffective and/or was insufficiently dosed to see a positive treatment effect. Our findings suggest that RAGT interventions in PD may be more effective in individuals with greater motor impairments.

Opportunities and challenges in the development of exoskeletons for locomotor assistance

Exoskeletons can augment the performance of unimpaired users and restore movement in individuals with gait impairments. Knowledge of how users interact with wearable devices and of the physiology of locomotion have informed the design of rigid and soft exoskeletons that can specifically target a single joint or a single activity. In this Review, we highlight the main advances of the past two decades in exoskeleton technology and in the development of lower-extremity exoskeletons for locomotor assistance, discuss research needs for such wearable robots and the clinical requirements for exoskeleton-assisted gait rehabilitation, and outline the main clinical challenges and opportunities for exoskeleton technology.

MotorSkins-a bio-inspired design approach towards an interactive soft-robotic exosuit

The work presents a bio-inspired design approach to a soft-robotic solution for assisting the knee-bending in users with reduced mobility in lower limbs. Exosuits and fluid-driven actuators are fabric-based devices that are gaining increasing relevance as alternatives assistive technologies that can provide simpler, more flexible solutions in comparison with the rigid exoskeletons. These devices, however, commonly require an external energy supply or a pressurized-fluid reservoir, which considerably constrain the autonomy of such solutions. In this work, we introduce an event-based energy cycle (EBEC) design concept, that can harvest, store, and release the required energy for assisting the knee-bending, in a synchronised interaction with the user and the environment, thus eliminating any need for external energy or control input. Ice-plant hydro-actuation system served as the source of inspiration to address the specific requirements of such interactive exosuit through a fluid-driven material system. Based on the EBEC design concepts and the abstracted bio-inspired principles, a series of (material and process driven) design experimentations helped to address the challenges of realising various functionalities of the harvest, storage, actuation and control instances within a closed hydraulic circuit. Sealing and defining various areas of water-tight seam made out of thermoplastic elastomers provided the base material system to program various chambers, channels, flow-check valves etc of such EBEC system. The resulting fluid-driven EBEC-skin served as a proof of concept for such active exosuit, that brings these functionalities into an integrated 'sense-acting' material system, realising an auto-synchronised energy and information cycles. The proposed design concept can serve as a model for development of similar fluid-driven EBEC soft-machines for further applications. On the more general scheme, the work presents an interdisciplinary design-science approach to bio-inspiration and showcases how biological material solutions can be looked at from a design/designer perspective to bridge the bottom-up and top-down approach to bio-inspiration.

WITHDRAWN: Immediate Adaptations to Poststroke Walking Performance Using a Wearable Robotic Exoskeleton

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What Do Older Adults and Clinicians Think About Traditional Mobility Aids and Exoskeleton Technology?

Mobility impairments can prevent older adults from performing their daily activities, which highly impacts quality of life. Powered exoskeletons, which are wearable robotic devices, can assist older adults by providing additional support to compensate for age-related decline in muscle strength. To date, little is known about the opinions and needs of older adults regarding exoskeletons, as current research primarily focuses on the technical development of exoskeleton devices and on groups with more severe mobility impairments such as people with spinal cord injuries. Therefore, the aim of this article is to inform the design of exoskeletons for older adults from a person-centered perspective. Interviews were conducted with seven older adults and six clinicians. Results indicated that exoskeletons can be a valuable addition to existing mobility devices to support older adults during walking and other actions necessary to perform their daily activities. Although reactions towards the concept of exoskeleton technology were positive, older adults did not currently perceive the need for an exoskeleton device. Exoskeletons for older adults should be easy to use; preferably, users should be able to put the device on and take it off independently. Moreover, the appearance of the exoskeleton should be as inconspicuous as possible, as most older adults do not like to advertise their need for assistive devices. At this point in time, the willingness to use exoskeleton technology will depend on personal needs and preferences.

Long-Term Effects of a Soft Robotic Suit on Gait Characteristics in Healthy Elderly Persons

As a walking assistive device for elderly persons, one of the major aims should be to improve and rehabilitate gait characteristics after long-term repeated use of the device. However, most of the existing research on walking assistive devices only emphasize their immediate effects, and there is limited research indicating the long-term effects. To address this gap, this paper experimentally validates the effects of our soft wearable robotic suit on gait characteristics of elderly persons after repeated use of the device for six weeks. Experimental results on four elderly subjects (age = 74.8 ± 5.0 year) show that, after six weeks of gait rehabilitation training by the robotic suit, the gait characteristics of the subjects were improved, leading to an increased walk ratio with an average of 9.8% compared with the initial state. The results of this research will benefit the potential use of the robotic suit in gait training and rehabilitation for elderly persons and also will be useful to the establishment of practical guidelines that maximize the training and rehabilitation effectiveness of the robotic suit.

Gait training using a robotic hip exoskeleton improves metabolic gait efficiency in the elderly

Robotic exoskeletons are regarded as promising technologies for neurological gait rehabilitation but have been investigated comparatively little as training aides to facilitate active aging in the elderly. This study investigated the feasibility of an exoskeletal Active Pelvis Orthosis (APO) for cardiopulmonary gait training in the elderly. Ten healthy elderly volunteers exhibited a decreased (-26.6 ± 16.1%) Metabolic Cost of Transport (MCoT) during treadmill walking following a 4-week APO-assisted training program, while no significant changes were observed for a randomly assigned control group (n = 10) performing traditional self-paced overground walking. Moreover, robot-assisted locomotion was found to require 4.24 ± 2.57% less oxygen consumption than free treadmill walking at the same speed. These findings support the adoption of exoskeletal devices for the training of frail individuals, thus opening new possibilities for sustainable strategies for healthy aging.

A wearable hip-assist robot reduces the cardiopulmonary metabolic energy expenditure during stair ascent in elderly adults: a pilot cross-sectional study

Background

Stair ascent is one of the most important and challenging activities of daily living to maintain mobility and independence in elderly adults. Recently, various types of wearable walking assist robots have been developed to improve gait function and metabolic efficiency for elderly adults. Several studies have shown that walking assist robots can improve cardiopulmonary metabolic efficiency during level walking in elderly. However, there is limited evidence demonstrating the effect of walking assist robots on cardiopulmonary metabolic efficiency during stair walking in elderly adults. Therefore, the aim of this study was to investigate the assistance effect of a newly developed wearable hip assist robot on cardiopulmonary metabolic efficiency during stair ascent in elderly adults.

Methods

Fifteen healthy elderly adults participated. The Gait Enhancing Mechatronic System (GEMS), developed by Samsung Electronics Co., Ltd., Korea, was used in the present study. The metabolic energy expenditure was measured using a K4b² while participants performed randomly assigned two conditions consecutively: free ascending stairs without the GEMS or robot-assisted ascending stair with the GEMS.

Results

There were significant differences in the oxygen consumption per unit mass (ml/min/kg), metabolic power per unit mass (W/kg) and metabolic equivalents (METs) values between the GEMS and NoGEMS conditions. A statistically significant difference was found between the two conditions in net oxygen consumption and net metabolic power, with a reduction of 8.59% and 10.16% respectively in GEMS condition (p < 0.05). The gross oxygen consumption while climbing stairs under the GEMS and NoGEMS conditions was equivalent to 6.38 METs and 6.85 METs, respectively.

Conclusion

This study demonstrated that the GEMS was helpful for reducing cardiopulmonary metabolic energy expenditure during stair climbing in elderly adults. The use of the GEMS allows elderly adults to climb stairs with less metabolic energy, therefore, they may experience more endurance in stair climbing while using the GEMS.

Trial registration

NCT03389165, Registered 26 December 2017 - retrospectively registered

Influence of a Soft Robotic Suit on Metabolic Cost in Long-Distance Level and Inclined Walking

Metabolic cost during walking is positively linked to exercise intensity. For a walking assistive device, one of the major aims should be the maximization of wearers' metabolic benefits for different walking situations. Toward this goal, this paper experimentally evaluates the influence of an authors' soft robotic suit, which has been developed to assist hip flexion for energy-efficient walking of elderly persons in daily life activities, on metabolic cost reduction in the long-distance level and inclined walking. Experiment results show that, for a 79-year-old healthy male subject, the robotic suit significantly reduced metabolic cost in the condition of the robotic suit worn and powered on compared with the condition of worn but powered off.

Gait performance and foot pressure distribution during wearable robot-assisted gait in elderly adults

BACKGROUND

A robotic exoskeleton device is an intelligent system designed to improve gait performance and quality of life for the wearer. Robotic technology has developed rapidly in recent years, and several robot-assisted gait devices were developed to enhance gait function and activities of daily living in elderly adults and patients with gait disorders. In this study, we investigated the effects of the Gait-enhancing Mechatronic System (GEMS), a new wearable robotic hip-assist device developed by Samsung Electronics Co, Ltd., Korea, on gait performance and foot pressure distribution in elderly adults.

METHODS

Thirty elderly adults who had no neurological or musculoskeletal abnormalities affecting gait participated in this study. A three-dimensional (3D) motion capture system, surface electromyography and the F-Scan system were used to collect data on spatiotemporal gait parameters, muscle activity and foot pressure distribution under three conditions: free gait without robot assistance (FG), robot-assisted gait with zero torque (RAG-Z) and robot-assisted gait (RAG).

RESULTS

We found increased gait speed, cadence, stride length and single support time in the RAG condition. Reduced rectus femoris and medial gastrocnemius muscle activity throughout the terminal stance phase and reduced effort of the medial gastrocnemius muscle throughout the pre-swing phase were also observed in the RAG condition. In addition, walking with the assistance of GEMS resulted in a significant increase in foot pressure distribution, specifically in maximum force and peak pressure of the total foot, medial masks, anterior masks and posterior masks.

CONCLUSION

The results of the present study reveal that GEMS may present an alternative way of restoring age-related changes in gait such as gait instability with muscle weakness, reduced step force and lower foot pressure in elderly adults. In addition, GEMS improved gait performance by improving push-off power and walking speed and reducing muscle activity in the lower extremities.

TRIAL REGISTRATION

NCT02843828 .

Regional Variation in Skeletal Muscle and Adipose Tissue FDG Uptake Using PET/CT and Their Relation to BMI

RATIONALE AND OBJECTIVES

Skeletal muscle metabolism is a primary contributor to whole-body energy expenditure. Currently, methods to measure changes in skeletal muscle metabolism in vivo are limited. Our objectives were to characterize the regional variation in skeletal muscle and adipose tissue (AT) FDG uptake as a surrogate for glycolytic metabolism using ¹⁸F-2-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in healthy men and to correlate these findings to body mass index (BMI).

MATERIALS AND METHODS

Eighteen healthy men were enrolled and underwent FDG-PET/CT. The mean standardized uptake value of 14 skeletal muscles and two AT regions was measured and linear regression analysis was performed to identify metabolic predictors of BMI.

RESULTS

FDG-PET/CT reliably detected changes in skeletal muscle and AT depot metabolic activity based on location. The most metabolically active muscles were those used for posture and breathing, which have the highest percentage of reported type I muscle myofiber content. Visceral AT tended to have a higher FDG uptake than subcutaneous AT. The mean standardized uptake value of VAT, pectoralis major, and gluteus maximus muscles accounted for 64% of the variance in BMI.

CONCLUSIONS

FDG-PET/CT can be used to quantify the regional variation in glucose metabolism of multiple skeletal muscle groups and AT depots.

A Wearable Hip Assist Robot Can Improve Gait Function and Cardiopulmonary Metabolic Efficiency in Elderly Adults

The aims of this paper were to investigate the effectiveness of a newly developed wearable hip assist robot, that uses an active assist algorithm to improve gait function, muscle effort, and cardiopulmonary metabolic efficiency in elderly adults. Thirty elderly adults (15 males/ 15 females) participated in thispaper. The experimental protocol consisted of overground gait at comfortable speed under three different conditions: free gait without robot assistance, robot-assisted gait with zero torque (RAG-Z), and full RAG. Under all conditions, muscle effort was analyzed using a 12-channel surface electromyography system. Spatio-temporal data were collected at 120 Hz using a 3-D motion capture system with six infrared cameras. Metabolic cost parameters were collected as oxygen consumption per unit (ml/min/kg) and aerobic energy expenditure (Kcal/min). In the RAG condition, participants demonstrated improved gait function, decreased muscle effort, and reduced metabolic cost. Although the hip assist robot only provides assistance at the hip joint, our results demonstrated a clear reduction in knee and ankle muscle activity in addition to decreased hip flexor and extensor activity. Our findings suggest that this robot has the potential to improve stabilization of the trunk during walking in elderly adults.

Experimental Evaluation of Energy Efficiency for a Soft Wearable Robotic Suit

This paper presents a new soft wearable robotic suit for energy-efficient walking in daily activities for elderly persons. The presented robotic suit provides a small yet effective assistive force for hip flexion through winding belts that include elastic elements. In addition, it does not restrict the range of movement in the lower limbs. Moreover, its structure is simple and lightweight, and thus wearers can easily take the device on and off by themselves. Experimental results on nine elderly subjects (age = 74.23.7 years) show that the robotic suit worn and powered on (PON) significantly reduced energy expenditure by an average of 5.9 % compared with the condition of worn but powered off (POFF). Furthermore, compared with the POFF condition, there was a significant improvement in gait characteristics in the PON condition for all subjects.

Automated stride assistance device improved the gait parameters and energy cost during walking of healthy middle-aged females but not those of young controls

[Purpose] The aim of this study was to clarify the effects of an automated stride assistance device on gait parameters and energy cost during walking performed by healthy middle-aged and young females. [Subjects and Methods] Ten middle-aged females and 10 young females were recruited as case and control participants, respectively. The participants walked for 3 minutes continuously under two different experimental conditions: with the device and without the device. Walking distance, mean walking speed, mean step length, cadence, walk ratio and the physiological cost index during the 3-minutes walk were measured. [Results] When walking with the stride assistance device, the step length and walk ratio of the middle-aged group were significantly higher than without it. Also, during walking without assistance from the device, the physiological cost index of the middle-aged group significantly increased; whereas during walking with assistance, there was no change. The intergroup comparison in the middle-aged group showed the physiological cost index was lower under the experimental condition with assistance provided, as opposed to the condition without the provision of assistance. [Conclusion] The results of this study show that the stride assistance device improved the gait parameters of the middle-aged group but not those of young controls.

Effects of a wearable exoskeleton stride management assist system (SMA®) on spatiotemporal gait characteristics in individuals after stroke: a randomized controlled trial

Background

Robots offer an alternative, potentially advantageous method of providing repetitive, high-dosage, and high-intensity training to address the gait impairments caused by stroke. In this study, we compared the effects of the Stride Management Assist (SMA®) System, a new wearable robotic device developed by Honda R&D Corporation, Japan, with functional task specific training (FTST) on spatiotemporal gait parameters in stroke survivors.

Methods

A single blinded randomized control trial was performed to assess the effect of FTST and task-specific walking training with the SMA® device on spatiotemporal gait parameters. Participants (n = 50) were randomly assigned to FTST or SMA. Subjects in both groups received training 3 times per week for 6–8 weeks for a maximum of 18 training sessions. The GAITRite® system was used to collect data on subjects’ spatiotemporal gait characteristics before training (baseline), at mid-training, post-training, and at a 3-month follow-up.

Results

After training, significant improvements in gait parameters were observed in both training groups compared to baseline, including an increase in velocity and cadence, a decrease in swing time on the impaired side, a decrease in double support time, an increase in stride length on impaired and non-impaired sides, and an increase in step length on impaired and non-impaired sides. No significant differences were observed between training groups; except for SMA group, step length on the impaired side increased significantly during self-selected walking speed trials and spatial asymmetry decreased significantly during fast-velocity walking trials.

Conclusions

SMA and FTST interventions provided similar, significant improvements in spatiotemporal gait parameters; however, the SMA group showed additional improvements across more parameters at various time points. These results indicate that the SMA® device could be a useful therapeutic tool to improve spatiotemporal parameters and contribute to improved functional mobility in stroke survivors. Further research is needed to determine the feasibility of using this device in a home setting vs a clinic setting, and whether such home use provides continued benefits.

Trial registration

This study is registered under the title “Development of walk assist device to improve community ambulation” and can be located in clinicaltrials.gov with the study identifier: NCT01994395.

Reduction in energy expenditure during walking using an automated stride assistance device in healthy young adults

OBJECTIVE

To investigate the effects of an automated stride assistance device that assists hip joint flexion and extension movement in energy expenditure during walking in healthy young adults using an expired gas method.

DESIGN

Prospective, single-group design to compare the differences of energy expenditure between 2 assistive conditions.

SETTING

Laboratory.

PARTICIPANTS

Healthy volunteers (N=10) aged 21 to 32 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Oxygen consumption per unit time (V˙o2) cost (ml·kg(-1)·m(-1)), and heart rate (beats/min) were measured in 2 assistive conditions (with 3-Nm hip motion assistance and without assistance) and at 2 walking speeds (comfortable walking speed [CWS] and maximum walking speed [MWS]).

RESULTS

There were no significant differences in walking speed between the with- and without-assistance conditions at either the CWS or MWS. The V˙o2 cost and heart rate were significantly reduced in the with-assistance condition compared with the without-assistance condition, at both the CWS and MWS. The reduction in the V˙o2 cost during the with-assistance condition, relative to the without-assistance condition, was 7.06% at the CWS and 10.52% at the MWS.

CONCLUSIONS

The automated stride assistance device is useful for reducing energy expenditure during walking in healthy adults. Further studies are warranted to investigate if this device provides substantial help to individuals with impaired mobility as a result of strength deficits.

Relationship between whole body oxygen consumption and skeletal muscle glucose metabolism during walking in older adults: FDG PET study

BACKGROUND AND AIMS

The purpose of this study was to determine the relationship between whole body energy metabolism measured as oxygen consumption (VO2) and local muscle activity measured by positron emission tomography (PET) and [18F]fluorodeoxyglucose (FDG).

METHODS

Ten community- dwelling older women (73-83 yrs) had FDG PET and VO2 measured while walking at a comfortable speed.

RESULTS

A significant positive correlation was found between VO2 and FDG uptake in the biceps femoris (r=0.83), gluteus minimus (r=0.67), gluteus medius (r=0.77) and pelvis section muscles (r=0.76). The subjects who showed high FDG uptake in the hip muscle group had significantly higher VO2 while walking, compared with subjects without high FDG uptake in the hip muscles.

CONCLUSIONS

These results indicate that FDG PET provides an index which reflects whole body energy metabolism during walking, and revealed that excess muscle activity in the hip muscles during walking plays a key role in increasing VO2 in older adults.

Development of PET radiopharmaceuticals and their clinical applications at the Positron Medical Center

The Positron Medical Center has developed a large number of radiopharmaceuticals and 36 radiopharmaceuticals have been approved for clinical use for studying aging and geriatric diseases, especially brain functions. Positron emission tomography (PET) has been used to provide a highly advanced PET-based diagnosis. The current status of the development of radiopharmaceuticals, and representative clinical and methodological results are reviewed.